ELEMENTYour Guid to Foundries in Pakistan

www.pfa.org.pk2nd Edition 2015

Industrializing Pakistan

It is encouraging to note that GIFA, METAIC THERMPROCESS and NEWCAST 2015 ended with the highest visitors and exhibitor's participation of more than 120 countries including Pakistan.GIFA demonstrated that it is the principle trade fair and international venue for the casting industry.

The delegation of PFA was well received by the organizers. I thank GIFA organizers for the welcome reception hosted in their honor.

The participation of Mecas Foundry (PFA member) as exhibitor received very good response by the international visitors and exhibitors.Their interest in castings and machined parts displayed were of great importance and portrayed a good image for Pakistan Foundry industry. Mecas Foundry has developed contacts

with many vendors and buyers. I wish the visitors from PFA may have purchased new technology for the improvement of their manufacturing capacities.

I feel our PFA members have the potential to export in European countries and can get international business. I will emphasis on them to find international customers to export their foundry products to improve economy of Pakistan.

I suggest, our foundry men can benefit from the casting simulation software installed in Foundry Service Centre and can improve the quality of casting productions to meet international standards for export benefit.Using simulation software technology foundry men can view casting defects at their computer screens. The increased efficiency and accuracy can be achieved by eliminating the defects well before moving to the shop floor. Reducing scrap and improving metal quality and increasing production rates are the outcomes of casting simulation software.

It is encouraging to note that “MAGMA-SOFT” has entered in Pakistan Casting Market and has made available its latest Magmas Soft version in one of the leading casting group of engineering in Lahore. I hope other foundries will take benefit from their expertise and will acquire latest technologies to improve their quality of Production.

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-0300 8673873

Joint SecretaryPakistan Foundry Association

Foundry Sector and its Export

GIFA Event Report 2015

Using No Bake Molding System to achieve a Competitive Edge

Development Of Aluminium-cer ia Composite By Using Stir Casting

Competitiveness through Automation

SHOT PEENING OF AUTOMOBILE PARTS

Development of Resin Coated Sand

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Pakistan is a country of 186.2 million people with 1640 foundries operating with an installed

capacity of 350,000 tons per year of Grey, SG Iron, Steel and Non-Ferrous castings. This does not

include aluminum die casting industry which is still working as small scale jobbing foundries. Most

of these foundries are engaged in the production of automotive parts, tractors, sugar mills

machinery parts, cement factories consumables, chemical factories consumables, agriculture

implements, heavy industrial castings, agriculture implements, pumps, valves, electric motors,

textile and cement machinery, processing industries and others.

Pakistan Foundry Association was established with the vision to provide a platform for the growth

of the foundry industry by improving skills and up-grading technology with special emphasis on

small and medium sized foundries. It is also a data bank of relevant subjects of interest for those

engaged in the business. The importance of the foundry engineering cannot be over

emphasized and the role it can play for the economic development of Pakistan with its high value

adding possibilities.

The objectives of PFA are . . .

" To facilitate export/ import related activities of the members.

" To represent the foundry industry at Domestic and International forums.

" To promote trade, commerce and manufacture of foundry products for the local and

global markets.

PFA is helping Pakistan Foundry Industry in gearing up to grow as a producer and exporter of

castings. It is worth mentioning that foundry products exports during the year 2013-14 was 263

million US Dollar (21%) out of total engineering goods export 1205 million US Dollar. These figures

are progressive and export from Pakistan including members of PFA and non-members while

looking at the last five years data…….

Looking at the export of foundry products the ministry of Commerce and Industry in Pakistan can

support the foundry industry for further growth for even better performance. Trade Development

Authority of Pakistan (TDAP) can play its role for further growth in export by foundry industry which

is one of the major contributors. It is regrettable that TDAP has no separate statistics for exports by

the foundry industry nor a separate desk to look after foundry industry.PFA has gathered and

prepared the above figures by the data of Bureau of statistics Islamabad for their consideration.

The inception of tractor and automotive assemblers introduced product quality awareness

among the foundry industry. The interchange-ability and quality consistency of cast components

required process mechanization and proper control of input materials. Developed countries

have started shifting their casting requirements to developing Asian countries including Pakistan.

We export foundry products to many countries in the world like USA, Germany, UK, Brazil,

Netherlands, Japan, Afghanistan, France, Saudi-Arabia, Italy, China, India etc. Pakistan has

tremendous growth potential and the world foundries can benefit from……….

Abdul Rashid, Secretary, PFA

Foundry Sector and its Export

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Ÿ Low labor cost

Ÿ Large population with a strong domestic demand

Ÿ Construction cost for new casting facilities and completion time is low

Ÿ Health & Safety compliances for molding binders are not stringent as the developed world

Ÿ Tooling cost and local development of auxiliary foundry equipment is low

Despite current economic situation, Pakistan is set to become a market for 115,882 cars in the year

2013-14 as compared to 106,968 in 2012-13 and 691,037 motor cycles in the year 2013-2014 as

compare to 710,553 in the year 2012-13 in addition to bus, truck and farm machinery sectors. To

fulfill the future demands of casting in Pakistan as well as for export destinations the Japanese/

Chinese auto giants and all, interested to invest with their strong foot print in Pakistan, or their

overseas vendors may invest in the foundry sector in Pakistan in order to reap the profits of the

rising demand in Pakistan.

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After five days Messe Düsseldorf delivers a very positive summary of "The Bright World of Metals" on

Saturday 20 June. The metal fairs quartet registered good marks on the exhibitors' as well as on the

visitors' side. In particular the internationality again increased distinctly and now amounts to 56

percent at the visitors and 51 percent at the exhibitors.

With 78,000 visitors from more than 120 countries GIFA, METEC, THERMPROCESS and NEWCAST

2015 in Düsseldorf were on the level of the previous events. The experts presented themselves in

high spirits to invest and the 2.214 exhibiting companies

reported on numerous business transactions with

customers from all over the world. Especially in the Asian

region there is a great demand for European

metallurgy and foundry technology corresponding

current requirements of the industry regarding the

saving of energy and resources. Two third of the visitors

are directly involved in investment decisions in the top

and middle management of their companies. On top

of the international visitor ranking there are experts from

India, Italy, Turkey, France and China .

Messe Düsseldorf Managing Director Joachim Schäfer: "The 'Bright World of Metals' shines brighter

than ever. The atmosphere in the fair halls was excellent every day. The trade visitors really

appreciated that complete machines and systems are presented here in Düsseldorf.

Accordingly, the sales talks run extremely positive." Global market leaders as well as companies

specialized in niche technologies evaluated their fair participation as very satisfactory. Trade

visitors evaluated best marks for GIFA, METEC, THERMPROCESS and NEWCAST: Up to 98 percent

regarded their trade fair visit as good.

Spokesmen of the exhibiting companies reported that they exactly met their target groups at the

fairs. At the GIFA these were precisely the experts of ferric, steel and non-ferrous metal castings as

well as of engineering. At the METEC the major visitor group traditionally came from iron and steel

production together with plant engineering and

construction, apparatus engineering and tool making.

This is also valid for THERMPROCESS. Especially experts of

automotive and gear manufacturing as well as of the

ancillary industry came to NEWCAST but also visitors

from engineering, apparatus engineering and tool

making played a decisive role.

The ecoMetals campaign has already been performed

for the second time in 2015 on the occasion of "Bright

World of Metals" and by this campaign the topic of

energy efficiency and saving of resources was

Prepared by: Miss Tanina Vellen, Press Department GIFA

Abdul Rashid, Secretary, PFA

GIFA Event Report 2015

obviously in the focus of the visitors' interest. Director Friedrich-Georg Kehrer: "For the customer

industries the recent technologies for the saving of resources and energy efficiency play a

considerable role in placing investments. Companies distinguishing themselves in these aspects

were in great demand as a visitors' target on the four fairs." Consequently, the "ecoMetals Trails"

were well booked leading interested trade visitors to the participants of the campaign. There the

companies presented their innovative technologies and thus could get in direct contact to

potential customers from all over the world.

The fairs were a complete success for the promoting associations - bdguss, VDMA, Stahlinstitut

VDEh and IVG Industrieverband Gießerei-Chemie - of GIFA, METEC, THERMPROCESS and

NEWCAST. The three VDMA trade associations of casting machines, foundry and rolling mill

equipments as well as of thermo process and waste engineering represented by their managing

director Dr. Timo Würz were pleased with the good course of the fairs: "The expectations were

exceeded. In particular we were very pleased about the internationality of the visitors. Also from

our participating companies we received a very good feedback. GIFA, METEC, THERMPROCESS

and NEWCAST again have given proof of their outstanding position as leading trade fairs for our

branches." Max Schumacher, spokesman of the general executive board of the federal

association of the German casting industry bdguss concludes: "The GIFA again demonstrated

that it is the principal trade fair and the international venue of the casting industry."

Also for the city of Düsseldorf fairs of such magnitude are a benefit: hotels are highly booked and

Rheinufer (banks of the river Rhine) and Altstadt offer best possibilities and facilities for the visitors

for a pleasant and successful conclusion of the fair days.

The precise date for the subsequent GIFA, METEC, THERMPROCESS and NEWCAST will be set

during the following weeks.

The exhibitors' assessment of the "Bright World of Metals" is extremely positive all round too:

Dieter Rosenthal, member of the Management Board of the SMS group thinks that the

combination of trade fairs is very positive for his company: "We are pleased to see that GIFA,

METEC, THERMPROCESS and NEWCAST managed to reach their visitor target again and were

able to increase their significance in the metal industry successfully. The combination of four

different trade fairs is an excellent platform particularly for companies like the SMS Group, as we

met customers from all over the world and from many different sectors at the same place and

time. This personal dialogue between experts is of elementary importance to us as plant

manufacturers."

Dr. Ioannis Ioannidis, CEO and President of Frech Gruppe, points out that the GIFA 2015 took

place in a prospectus economic surrounding: "We had

an extremely high number of international customers

with concrete plans to invest. Additionally several

business deals have been confirmed. The demand for

innovative products as well as the atmosphere was

promising. We are looking forward for the next GIFA

show in Düsseldorf."

Erich Brunner, Director of DISA and Wheelabrator had a

very successful GIFA in 2015: "GIFA was excellently

organized once again. There were large crowds of

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existing and potential customers from all over the world. The innovative solutions we exhibited,

such as complete blasting machine programs to satisfy all the standard and special requirements

of both large and small foundries as well as a global and locally based service network, attracted

a particularly large amount of attention. We from DISA and Wheelabrator are already looking

forward to providing further services to our customers after GIFA

Thomas Angerbauer, Market Segment Manager Foundry from KUKA Roboter GmbH, reports: "The

number of visitors and the interest shown in the products and solutions from KUKA Roboter and

KUKA Industries at GIFA 2015 definitely exceeded our expectations." His colleague Steffen

Günther, Vice President Casting Solutions, KUKA Industries GmbH, adds: "Countless meetings with

our customers on the stand have helped us to understand their requirements even better and to

identify the market trends. Automation of die casting was the main focus. The trade fair was

definitely a complete success for KUKA - we are looking forward to the next GIFA.The MAGMA

Managing Director Dr Marc C. Schneider says that GIFA 2015 was a very successful event for his

company: "The atmosphere was unusually positive and the visitors to our stand at the trade fair

showed very keen interest in the technical trends in the industry and in the optimization of their

processes. Both we and our MAGMA colleagues from all over the world were delighted by the

international visitors and plenty of new contacts." Dr Jörg C. Sturm from the MAGMA

management confirms: "GIFA is the leading trade fair for an entire industry. In spite of all the

communication media that are available nowadays, numerous innovations were presented for

the first time at the trade fair, which makes GIFA an indispensable event, quite apart from the

personal contacts to customers that are possible there.

Till Schreiter, Director of ABP Induction, found participation in GIFA/THERMPROCESS very

worthwhile again: "As expected, the trade fair was a tremendous success again. It pays off here

that the event only takes place every 4 years, so that customers are very interested and focus

intensively on the exhibits, in contrast to rival trade fairs which are not as attractive."

A delegation of 30 members of Pakistan Foundry Association also participated in GIFA trade fair. I

thank GIFA organizers and Mr. Merik Chromik- Protocol Manager for the welcome reception

hosted in their honor on the request of Liaison office of Messe Dusseldorf GmbH, Lahore, Pakistan.

Mecas Foundry, a leading foundry industry in Pakistan participated as an exhibitor in GIFA Trade

fair along with their castings and finished machined parts. Video presentation regarding Mecas

foundry was also displayed. A lot of potential customers (Mr. Herbert Althaus from HWS - Sinto

Company, TCT executives etc...) visited the stall. Their

interest in castings and machined parts displayed were

of great importance and portrayed a good image for

Pakistan Foundry industry. They appreciated the quality

and machinery installed in their industry. It was an

excellent opportunity to showcase and developed

business relations with International buyers through this

fair. Pakistan foundries have a great potential of export

due to low labor cost and still an economical market

although lying between two giant's producers of

casting China and India.

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Introduction to Nobake Casting

As the metalcasting industry's second favorite method for producing cast components (green

sand molding is the first), nobake molding has proven its worth as an efficient means to produce

medium and low volumes of complex castings in both ferrous and nonferrous metals

In the nobake process, sand is mixed with a chemical binder/catalyst system and then molded

around the cope and drag halves of the tooling. After a specified period of time (from as little as

10 sec to as long as the foundry requires depending upon mold size), the sand mixture hardens

(resembling a brick in strength) to form the mold halves and the tooling is drawn. Then, a refractory

coating may be applied to both mold halves before they are brought together to form one

complete mold for pouring. (Nobake molded cores also can be produced using a similar method

and assembled into the mold to form more complex shapes.)

What No bake Syaytem Offers

Nobake molding, like green sand molding, is known for its versatility. Virtually all metals can be

cast via nobake molding with component weights ranging from less than a pound to several

hundred thousand pounds. For casting designers, nobake molding offers:

Ÿ good dimensional tolerances (±0.005-0.015) because the rigidity of the mold withstands t h e

pressures exerted by the molten metal during casting;

Ÿ compatability with most pattern materials, including wood, plastic, metal, fiberglass and

styrofoam, allowing for inexpensive tooling options for casting runs as low as one. In addition,

nobake molding imparts minimal tooling wear;

Ÿ design flexibility for intricate casting shapes. The rigidity and tensile strength of nobake molds

allows for thin sections of 0.1-in. to be routinely produced. In addition, mold strength allows for

minimal draft and radii requirements in casting design.

Ÿ reduced opportunity for gas-related defects as the nitrogen content of most binder systems

used for nobake molding minimize susceptibility to gas porosity;

Ÿ fine surface finishes that can be upgraded further with the mold and core coatings to support

special finishing on the cast components such as paint or dressing. In addition, nobake casters

can alter their molding media make-up from basic silica sand to higher-end media such as

chromite or zircon sand for applications requiring X-ray quality and extreme pressure tightness;

Ÿ ability to work well with unique metalcasting quality enhancement tools such as metal filters,

ceramic runner systems and exothermic risers to improve casting properties.

Ÿ low to medium volume production capability with runs from 1-5000 parts/yr.

Some Important questions related to No bake system

How many cast components will you require per year?

Nobake molding typically is an option for production runs from 1-5000 castings/yr . Due to the

curing time required for the chemicals to harden the mold as well as the methods to distribute the

molding media on the pattern, the high productions achievable with green sand, permanent

mold or diecasting aren't possible with nobake. Nobake molding prefers cast components with

higher complexities in low to medium volume runs.

Prepared By: Muhammad Saqib AminQadcast Pvt Ltd(Qadri Group Of Companies)

Using No Bake Molding System to achieve a Competitive Edge

When should you choose nobake molding vs. green sand molding?

Anything that can be cast in a green sand mold can be cast in a nobake mold, but the reverse

isn't true.

Besides the number of castings that need to be produced, the decision between green sand and

nobake comes down to the complexity of the casting design. Since unfinished nobake molded

castings (without machining) typically cost 20-30% higher than green sand, designers and

purchasers sourcing to nobake molding must offset this price difference by taking advantage of

what the process offers. Significant reductions in machining costs can be achieved through the

process' tight tolerances and minimal dimensional variability and by designing in complex shapes

and geometries, thin walls, and reduced draft, radii and machine stock.

Tooling cost also plays a factor in this comparison. Green sand molds require compaction force

during the molding process, which means that the tooling must be able to withstand this force.

Nobake tooling doesn't have to withstand a strong compaction force (often only light vibrations),

allowing wood and plastic to be viable tooling materials. In addition, the lack of compaction

force in molding also allows nobake molders to use loose pattern pieces and other innovative

tooling options to increase casting complexity and add design features to the components.

What about pattern cost because you only require a few parts?

Pattern materials for nobake molding include wood, plastic, fiberglass, metal and styrofoam. This

allows the tooling cost to be minimized as much as if not more than any other production casting

process. In addition, with the styrofoam option for the Full Mold process (see "Nobake Meets Lost

Foam in Full Mold Process" sidebar), hard tooling doesn't even have to be created for small

production runs.

How do you design cast components for nobake molding?

Designing castings for traditional nobake molding follows many of the same principles used in all

other casting processes. Draft is required so patterns can be drawn, sharp corners and angles

should be minimized and uniform section thicknesses (especially in the same plane) should be

employed as much as possible. However, the process does allow for more daring designs. Consult

a nobake foundry with your ideas to determine how best to accomplish a specific casting

challenge.

Cost vise comparison of No Bake system and Sodium Silicate/CO2 Process

(A Case Study)

Detail of Operating Parameters

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Part Name

Material

Pouring Weight

Mold coating

Pouring Temperature

Melting Equipment

Slag Pot

Grey Cast Iron

5700 Kg

Graphitic coating (Spirit Based )

1300 degree C

Cupola Furnace

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Characteristics of ESTER hardened No-bake Alkaline Phenolic Resin

Resin

Alkaline phenolic resin is alkaline water solution of phenolic resin with very low free phenol

andformeldehyde.

Hardener

Hardener is generally carboxylic ether of polyol

Appearance Viscosity Specific

gravity

Free

Phenol

Free

Formeldehyde

Remarks

Deep red and

brown liquid

150

CmPa.s

@ 25

degree C

1.2~1.3

g/CC @ 25

degree C

0.5 % 0.2 % High strength

low

odour

Density Viscosity Ester content Stripping time

1.1~1.2 gm/CC

@ 25 degree C

30 CmPa.s

@ 25 degree C 98 % 20 minutes @ 20~25

degree C

CO2 Process Alpha Set

MOLDING MATERIAL COST

Variable Weight Rate Cost Variable Weight Rate Cost

Silica sand 14000

Kg

Rs. 4.5/

Kg

Rs.63000/- Silica sand 14000

Kg

Rs.4.5/-

Kg

Rs.63000/-

Sodium

silicate

1120

Kg

Rs.15.2/-

Kg

Rs.

17024/-

Resin (@

2% of wt of

sand)

280 Kg Rs.141/-

Kg

Rs.39480/-

CO2 140 Kg Rs.48/-

Kg

Rs.6720/- Hardener

(@ 20 % of

weight of

Resin)

56 Kg Rs.249/-

Kg

Rs.13944/-

CO2 Process Alpha Set

LABOUR COST

Molding Time 03 days Molding time 01 days

Molders 2 no. Rs.3600/- Molders 02 no. Rs.1200/-

Helpers 8 no. Rs.3600/- Helpers 04 no. Rs.1600/-

Fettling Time 06 days Fettling Time 1 day

Chipper men 03 no. Rs.9000/- Chipper men 02 no. Rs.1500/-

Total

Rs.16200/- Total Rs.4300/-

Sand

Reclamation zero

Sand

reclamation

(@ 70 %)

9800

Kg

Rs.4.5/-

Kg

Rs.Rs.44100/-

Total

Rs.

86744/- Total

Rs.72324/-

Variable Weight Rate Cost Variable Weight Rate Cost

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CO2 Process Alpha Set

MOLDING MATERIAL COST Rs.86744/- MOLDING MATERIAL COST Rs.72324/-

LABOUR COST Rs.16200/- LABOUR COST Rs.4300/-

Total Cost Rs.Rs.102944/- Total Cost Rs.76624/-

Molding Cost per Kg

Rs.18.06/-

Molding Cost per Kg

(with reclamation) Rs.13.44/-

Molding cost per Kg

(with out reclamation)Rs. 21.17/-

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Mr. Sikandar Mustafa Khan- President, Pakistan Foundry Association hosted a sumptuous Iftar cum Dinner in the honor of PFA members at Pearl Continental Hotel Lahore on Friday July 03, 2015.It was a good opportunity for all participants to get together and develop better understanding and introduction with each other of old and new members. Such activities always b e n e c i a l f o r business relations and knowhow of each other “who is who”. It was e n c o u r a g i n g t h a t m a j o r i t y members of PFA b e l o n g i n g t o Lahore, Gujranawal, Faisalabad and SMEDA representative were present. The Iftar dinner was mouth watering and delicious, liked by every participant. Mr. Asim Qadri thanked all the participants to spare their precious time for the annual Iftar dinner especially those who have travelled form Faisalabad and Gujranwala and Lahore too. He was thankful to Dr. Fazal Ahmed Khalid (vice chancellor, U.E.T Lahore) and Mr. Javed Afzal - Project Director SMEDA for their participation. He added PFA organize such iftar dinner every year and I request everyone to do come in future too. There were 35 guests who participated in this Iftar dinner. Mr. Sikander Mustafa Khan said that it's my pleasure to meet all of you today and invite you to participate in the next annual Iftar dinner also.

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Abstract:

Development of aluminum alloy based casting composite materials via stir casting is one of the

prominent and economical route for development and processing of metal matrix composites.

Properties of these materials depend upon many processing parameters and selection of matrix

and particulates. Literature reveals that most of the researchers are using aluminum matrix with

SiC, ZnO and Al2O3 particles for achieving good mechanical and electrochemical properties

whereas, insufcient information is available on aluminum matrix composite incorporated with

CeO2 particles. The present research was conducted to investigate the effect of CeO2 particle

on mechanical and electrochemical properties of aluminum composite material using simple

foundry melting and casting route.

Key words: Stir casting, aluminium alloy, ceria, particulate composite

1. Introduction:

Modernization in the eld of science and technology increases the demand in the developments

of advanced engineering materials for various applications. These area demands light weight,

high strength, good tribological and electrochemical properties. Such demands can only be met

by development and processing of aluminium metal matrix composite materials

(Gopalakrishnan and Murugan, 2012; Moses et al., 2014; Sajjadi et al., 2012).

Literature review indicates that aluminum can be used in corrosion application as a sacricial

anode in cathodic protection system. The formation of passive layer within a very short time, is the

main reason due to which pure aluminum could not achieved industrial attraction. To overcome

these difculties aluminium is alloyed with Cu, Zn, Mg, etc. and different ceramic particulates (like

SiC, ZnO and Al2O3) are added to it by different researchers (Bharath et al., 2014; Idenyi et al.,

2009; Kumar et al., 2013; Shibli et al., 2008).

The main challenge in the development and processing of engineering materials is to control the

microstructure and properties. The processing of particulate metal matrix composite involves two

major processes (1) powder metallurgy route (2) liquid cast metal technology. The powder

metallurgy process has its own limitation such as processing cost and size of the components.

Therefore only the casting method is to be considered as the most optimum and economical

route for processing of aluminium composite materials. Stir casting is a casting method that

includes: melting of metal; addition of ceramic particles in molten metal under controlled

mechanical stirring system. Schemetic diagram of stir casting device is shown in Fig. 1 (Bauri et

al., 2011; Brabazon et al., 2002; Jokhio et al., 2011).

The present work was planned to investigate the effect of CeO2 particle on mechanical and

electrochemical properties of aluminum composite material using simple foundry conventional

casting. The details of the research work are given in the subsequent sections.

Umair Aftab*, M. I. Abro , Moazam Baloch , M. H. Jokhio Department of Metallurgy & Materials Engineering, Mehran UET, Pakistan

* umair.aftab@faculty.muet.edu.pk

Development Of Aluminium-ceria Composite By Using Stir Casting

Fig. 1: Schematic diagram of stir casting device

2. Materials and Method:

For present work aluminum ingot, zinc ingot and cerium oxide (ceria) of 1-3mm grains were

purchased from market. Composition of aluminum, zinc and ceria is described elsewhere (Aftab,

2012; Aftab et al., 2012). Ceria particles were ground in High-speed shimmy ball mill (Mtixl, SFM-1)

for 30 min and 60 min time intervals and the particles produced were labelled as micro-30 and

micro-60 respectively. The particle size distribution of micro ceria was determined using Horriba

Laser Particle Size Analyser (Model: LA-300). Aluminum-5% Zinc alloy was heated up to 750oC in pit

furnace and micro ceria particles (composition shown in Table 1) were added in the molten bath.

Temperature was kept constant and bath was mechanically agitated continuously to properly

mix the particles.

Table 1. Aluminum-5% Zinc-Ceria Composite Composition

Aluminum -5% Zinc-Ceria samples were ground initially by using emery paper of 320 to 1000 mesh

size and polished using velvet cloth. Keller's etch solution was used to etched the samples.

Scanning Electron Microscope (Model: JEOL: JSM-6380L) was utilized to assess the microscopic

texture of the samples. The VHN hardness of the composite samples was checked by using Vickers

Hardness Tester (Model: Masuzawa Seiki Co. Ltd. MV-1) at 1Kgf load.

Open circuit potential (OCP) and close circuit potential (CCP) of Auminium-5% Zinc-Ceria

composite were investigated to inspect the electrochemical properties of the composite. In OCP

investigation samples were made as anode and immersed in 3% brine solution kept at 30 ± 2oC for

seven days. After every 24 hr, potential difference of test anodes was determined using

copper/copper sulfate (CCS) reference electrode. In CCP investigation Auminum-5% Zinc-Ceria

and mild steel samples were made as anode and cathode respectively. Composite anodes were

mechanically attached with mild steel cathode and immersed in 3% brine solution for the period

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Composition AZC-1 AZC-2 AZC-3 AZC-4 AZC-5 AZC-6 AZC-7

Ceria NA 0.2%

(micro-30)

0.4%

(micro-30)

0.6%

(micro-30)

0.2%

(micro-60)

0.4%

(micro-60)

0.6%

(micro-60)

Aluminum-5 % Zinc balance balance balance Balance Balance balance Balance

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of seven days at 30 ± 2oC. After every 24 hr, emf difference of anode and cathode was

determined by using copper/copper sulphate (CCS) reference electrode.

3. Results and Discussion:

The particle size distribution of micro ceria particles ground for 30 min and 60 min is shown in Fig. 2.

It can be seen that 80% passing is achieved at 10 µm and 1.25 µm particle size in case of 30 min

and 60 min grinding time respectively. Sufcient reduction in 80% passing size achieved at

additional 30 min grinding indicates that ceria is highly fragile due to which it has better

grindability.

Fig. 2: Cumulative particle distribution of 30min and 60 min ground sample

The surface morphology of aluminum -5% zinc-ceria samples observed under Scanning Electron

Microscope is shown in Fig. 3. It can be seen that pits are rarely visible in all types of anode tested.

It is also visible in the Fig. 3(g) that agglomeration of ceria particles was increased with the

addition of ceria particles ground for 60 min. The agglomeration of ceria particles can be

attributed with their ne size distribution. Inappropriate distribution and clustering of ceria

particles recommended that more efcient mechanical mixing is required at elevated

temperatures (Jokhio et al., 2011).

Fig. 4 shows the hardness result of aluminum-5% zinc-ceria composite samples on the basis of

concentration of ceria particles, which indicates that with increasing micro-ceria particles

concentration hardness was increased. Signicant rise in hardness can be explained with the

understanding that ceria is a ceramic material, while ceramics have high hardness and wear

resistance properties. In addition, the solution strengthening mechanism may explain the role of

ceria in increasing hardness of the samples.

(a) (b) (d)

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Fig. 3: Aluminum-5% zinc- ceria composite SEM micrographs at 150 X

(a) AZC-1, ) (b) AZC-2, (c) ) AZC-3, (d) ) AZC--4, (e) ) AZC-5, (f) ) AZC-6 and (g) ) AZC-7

Fig. 4: Aluminum-5% zinc- ceria composite Hardness

Fig. 5 indicates the emf (OCP) of all Aluminum-5% zinc- anodes, the emf was remain at -1.0 volts

(mean) excluding AZC-3 anode whose emf was -0.8 volts (mean). The emf trend for seven days of

anodes with and without addition of ceria indicates that ceria has efciently stabilized the emf at -

1.0 volts. To know for how long emf of anode of AZC-6 and AZC-7 composition can stabilized the

emf at -1.0 volts, the emf results were extrapolated for three month and was noted that emf of

ceria added anodes were remained at -1.0 volts ±0.1 whereas emf of anode without ceria

reached below -0.8 volts.

(d) (e)

(f) (g)

22

Fig. 5: Time vs.OCP graph [AZC-1 to AZC-7]

Emf trend of Aluminum-5% zinc- ceria anodes in CCP shown in Fig. 6, point out that emf difference

of AZC-3 and AZC-7 anodes was moved to -0.8 volts, whereas CCP emf of remaining was

remained at -1.0 volts (mean). Furthermore, AZC-1 and AZC-4 anodes reveal unstable emf in

comparison with rest of the anodes samples. Quite constancy in emf was seen after one day in

cathode emf is evident.

Fig. 6: Time vs. CCP graph [AZC-1 to AZC-7 (anode+cathode)]

4. Conclusion:

Composite casting of Aluminum-5%Zn with ceria particles was successfully done and good

mechanical and electrochemical properties were achieved. Open and asymmetrical pits were

rarely noted in samples containing ceria particles. In few samples by raising the amount of ceria in

the composite, clustering of ne particles becomes the cause of wide pits. The hardness of

Aluminum-5% Zinc anode is considerably increased by the addition of ceria particles. Adding

ceria in Aluminum-5% Zinc anode did not alter the emf of anodes. It was worth eminent that by the

addition of ceria in Aluminum-5% Zinc anode emf is stabilized. In OCP and CCP system it was clear

that Aluminum-5% Zinc anode samples added with micro-60 samples efciently inhibit the emf of

mild steel cathode.

References:

1. Aftab, U., (2012) Manufacturing of Nano-Ceria Al-Zn Based Sacricial Anode for Cathodic

Protection (Masters of Engineering). Mehran University of Engineering and Technology,

Jamshoro.

2. Aftab, U., Abro, M.I., Khanji, H.,

Baloch, M.M., Jokhio, M.H., Maitlo, I.,

(2012) Preceding EESD 2012, Mehran

Un ivers i ty of Engineer ing and

Technology, Jamshoro.

3. Bauri, R., Yadav, D., Suhas, G., (2011)

Mater. Sci. Eng. A 528, 4732-4739.

4. Bharath, V., Nagaral, M., Auradi, V.,

Kori, S.A., (2014) Procedia Mater. Sci. 6, 1658-

1667.

5. Brabazon, D., Browne, D.J., Carr, A.J.,

(2002) Mater. Sci. Eng. A 326, 370-381.

6. Gopalakrishnan, S., Murugan, N.,

(2012) Part B Eng. 43, 302-308.

7. Idenyi, N.E., Ekuma, C.E., Owate, I.O.,

Okeke, C.E., (2009) Chalcogenide Lett. 6.

8. Jokhio, M.H., Panhwar, M.I., Unar,

M.A., (2011) Mehran Univ. Res. J. Eng.

Technol. 30.

9. Kumar, A., Lal, S., Kumar, S., (2013) J.

Mater. Res. Technol. 2, 250-254.

10. Moses, J.J., Dinaharan, I., Sekhar, S.J.,

(2014) Procedia Mater. Sci. 5, 106-112.

11. Sajjadi, S.A., Ezatpour, H.R., Torabi

Parizi, M., (2012) Mater. Des. 34, 106-111.

12. S h i b l i , S . M . A . , A r c h a n a , S . R . ,

Muhamed Ashraf, P., (2008) Corros. Sci. 50,

2232-2238.

33

Low Cost Automation using Compressed Air leads to Lower Manufacturing Costs Gujranwala

June 10, 2015- "Compared to electricity, air proves to be an excellent source of energy, which

yields efficient production and saves money as well" Said by Imtiaz Rastgar, Ex-CEO, Engineering

Development Board, Ministry of Industries, Islamabad, during a seminar at Gujranwala.

The seminar focused on various techniques which can be adopted by manufacturing units to

standardize their practices as well as by lowering cost of production. This is done by using air

cylinders, air motors, and grippers etc to speed up production and eliminate unnecessary labor

costs.

Rastgar & Co, The Compressed Air Specialist and authorized distributor of CompAir Air

Compressors in Pakistan, in collaboration with Gardner Denver FZE organized a seminar on "Use of

Compressed Air for Profitable Production in Manufacturing" for Gujranwala Industrialists. The

speakers on the occasion were Mr. Imtiaz Rastgar who is also an Engineering Sector Expert CBI

and Mr. Maqsood Zulfqar; CEO Rastgar & Co.

With changing production trends, it is important to adopt the best practices that are currently

available to the industrialists. There is a need to look into the varied forms of energy production in

order to increase the productivity while bearing minimum cost. For any industry, its success lies in

the quality of machinery being used by it, but it is also important to avoid wastage of energy,

place and material, that can occur if proper utilization of sources and services don't prevail.

Mr. Maqsood, who is an expert on German Air Compressors, provided the audience in the

Seminar with useful information regarding CompAir Air Compressors. He has been affiliated with

the Compressed Air Industry for the past 35 years. He said, "Compressed Air is often described as

the fourth utility and plays a fundamental part in the modern industrial world. Compressed air

accounts for about 10% of the global energy used in industries today."

CEOs, Technical Directors and Technical Managers from the Industrial Sector of Gujranwala,

including Master Poly Plastic Industries , Super Asia Appliances, Tahir Industries Metallisers, Haroon

Textile, Alkaram Textile, Lahore Fans, Jodhala Complex Pvt. Ltd, Kundan Ceramics, AGFA

Ceramics, 5 Start Ceramics, KPI Bottle Cover, Pioneer Industries Pvt. Ltd, Indus Home Appliances,

BOSS International Plastic Furniture, GIFT University, Sadar Family Packages, Mater Beverages

attended the seminar.

Rastgar & Company prioritizes a strong and sound base with its customers and thrives to build a

long lasting relationship with them. Training and workshops are at the forefront of its Marketing

Strategies. Rastgar & Co in association with Gardner Denver provides all sectors of the

compressed air products like compressed air audits, warranty and service offering, qualified,

factory-trained service technicians, original spare parts and lubricants, worldwide spare parts

and distribution network. (www.rastgar-co.com)

26

Competitiveness through Automation

Imtiaz A. Rastgar

Foundry News Technical Articles Events

28

Introduction

Abrasive blasting is a process of impenging abrasive particles with high velocity over metal

surface. It ius very commonly used as a finishing process in automobile component

manufacturing industries. Purpose of this process is descaling, deburring, peening, polishing, stress

relieving, deflashing and cleaning. The abrasive particles are of irregular shape cast iron grit and

sand particles are commonly used for cleaning, descaling and deburring. It should be noted that

in shot blasting spherical shot particles are useed for cleaning, descaling and deburring. It should

be noted that in shot blasting spherical short particles are used for above purposes. Basically there

is no difference bwteen shot blasting and shot peening.The term shot peening is commonly used

where above purposes are secondary but the main purpose is to indicate residual compressive

stresses in the metal surface to improve their fatigue life. Shot peening process involve complex

physical processes and results obtained are related to degree of control of peening conditions.

Perhaps, the most under-valued process in today's industrial work is that of shot peening, which

may be due to lack of appreciation of its exceptiional merits. This paper deals with greater details

about shot peening mechanism, process and applications.

Shot peening is a cold working process in which spherical steel shots or glass beads or shots of

suitable material and size are allowed to impinge with relatively high velocity on the surface of

metal parts of automobile, aircraft and other machines. This results into plastic deformation of the

peened surface thereby residual compressive stresses are included in the material upto a certain

depth which prevents the formation of surface cracks.

It is well known that a crack will not propagate into a compressed layer. As nearly all fatigue and

stress corrosion failure originate at the surface of a part, the layer of compressive stress induced by

shot peening produces the tremendoius increase in life.

When a shot strike the metal surface it results into plastic deformation and forms a dent below the

shot. Th residual stress distribution, its magnitude and depth below the dent is shown in Fig.1.

Fig. 1 Residual stress distribution below the dent produced by impinging a shot over metal surface.

The maximum compressive residfual stress produced at or near the surface is at least as great as

half the ultimate tensile strength of the material under peening.

Fig. 2 shows the yield zone below the dent which is about eight times the volume of the dent.Yield

zone produced by peening depends upon diameter and velocity of shot. Parts like compressor

By Chirag ModiDirector-TechnicSurface Finishing Equipment Co.Jodhpur-INDIA

E-mail: sfecjodhpur@gmail.com

SHOT PEENING OF AUTOMOBILE PARTS

and turbine rotor and stator blades usually require peening of the total surface. Under given

peening conditions for a componet shot exposure time for saturation, that is, for full coverage

[98% coverage] is to be established.There can be situations in service where controlled peening

and spot peening are to be used and there again shot exposure peening time is to be established

for required peening intensity in each case.

Fig. 2 Yield zone below the dent.

Exposure time beyond saturation or full coverage does not increase the volume of yield zone

appreciable but slightly increase it. Fig. 3 shows peened surfaces for one saturation time, twicxe

saturation time and thrice saturation time respectively.

Mechanism of Shot Peening Process Leading to Improvement in Fatigue Strength.

Fatigue failure of a component usually occurs due to the process of initiation of surface crack,

then its propogation and finally fracture into two places without showing any deformation in cross

section. Fatigue cracks usually originate at the surface because [i] surface crystals are inherently

weak [ii] maximum stress usually occurs at the surface in most common type of loading as

bending, torsion and combination of the two i.e. bending and torsion.These stresses are tensile in

nature causing crack initiation, [iii] some stress concentration due to geometry of the object may

always be present at the surface.

When a metal part is shot peened its surface is subjected to slight indentations, causing slight

permanent stretching of the metal in the surface and at a short distance below the surface, and

acts to strengthen the surface zone of metal by changing the shape and orientation of the

crystalline grains so as more effectively to resist flow or fracture. Thus the metal in the surface zone

is made some what stronger than the metal underneath this zone.

But the change of shape and orientation of crystalline grains is not the only change caused by

shot peening. As a the individual piece of shot strike the metal each one sets up localized stress -

longitudinal, transverse and perpendicular compression at the surface, and at a slight distance

below it. After the shot bounces off some residual stress remains in and near the surface - a

longitudinal compressive stress, a transverse compressive stress and probably vertical

compressive stress, a little below the surface. The net result of this state of three dimensional stress

tends to offset any logitudinal tensile stress applied by a load or bending moment. Then, since

tensile tress of a given internsity has more tendency to cause the start of a fatigue crack than a

compressive stress set by shot peening, in general, increases the fatigue strength of a shot

peened piece. It is recognized that shot peening unless very poorly done or carried to an

excessive intensity, does cause an increase in the fatigue strength of a metal.

Utility of Shot Peening Process

Shot peening is used to eliminate failures of existing designs, or to allow the use of higher stress

levels, which, in turn, permit weight reduction for new designs.

29

30

Shotr peening has been done commercially to following parts :-

Rocer Arms Connecting rods Tank pins

Track links Tank Treads Chain links

Jet Engine blades Steering knuckles Axles

Helical gears Fillets Transmission shafts

Pinion gears Cylinder block Bearings

Gun Extractors Bevel gears Impeller parts

Propeller shafts Compressor Blades Crank shafts

Engine Quills Crank cases Splines

Pivot shafts Universal joimts Leaf springs

Pistons Helical springs Valve inserts

Drill steel Piston Pins Milling cutters

Ring gears Valve spring washers

Shot peening is not only commercially used for improving fatigue life of above components but it

is equally good for prevention of stress cororosion cracking that is failure by cracking under

combined action of corrosion and tensile stress. No stress corrosion cracking has been reported

from compressive stresses. Therefore compressive stresses induced by shot peening will retard

stress corrosion cracking of all materials which are susceptible to stress corrosion like high strength

aluminium alloys, magnesium, titanium, copper, steel and stainless steel.

Shot peening produces cold worked surface layer which makes austenitic stainless steel not

susceptible to intergranuler corrosion mode.

The minute pockets that are produced at the surface through shot peening act as oil reservoirs,

thus resulting in longer lubricant retention .

Fi g . 3 Shot Peening over the Surface.

It is advisable to shot peen automobile parts which undergo heavy grinding to change residual

stress in the surface fromtensile to compressive.

Shot peening before chrome plating will counter act the harmful effect of plating on the fatigue

life of metal parts.

It is also possible to change the shape of parts with relatively thin cross section by shot peening

then selectively.Thus it is used for straightening the parts.

In the same manner in which shot peening has been used to straighten parts, it can be used to

form certain parts in production. Integrally stiffened wing skins arean excellent application of shot

peen forming.

The heat-affected areas adjacent to weld are nearly always in tension, which can decrease the

fatigue life of welded assembly. Shot peening, by inducing a compressive stress in the surface can

substantially increase the fatigue life of welded assemblies.

Fig. 4 Schematic view of Induction Syphen System

Fig.5 Schematic view of Gravity System .

Many times during Electro Discharge machining due to thermal stresses, plastic deformation and

shrinkage induce residual tensile stresses in the work piece.Shot peening by producing residual

compressive stresses have been found to be very beneficial in restoring fatigue strength of parts

that have been electro discharge machined.

It has been observed that during high cycle fatigue the components which have undergone

Electro chemical machining [ECM] fail at lower stress level due to surface softening occurred in

ECM. Shot peening treatment more than restores the endurance strength.

Shot peening has worked quite successfully for antigalling [anti-adhesive wear] applications on

such materials as titanium 6-4 stainless steel type 300 and 400 series, 17-4 PH, Inconed 718 and

X750, Monel K-500 and others. It has also been found that shot peening willprevent scoring on

such parts as tappet faces, cams, gears,etc. which are in sliding contact under high loads.

Auto frettaqge is internal pressurizing of a thick wall cylinder beyond the yield strength of the

material. Inelastic deformation will occur to some distance into the wall from the internal surface

during pressurization. Upon removal of this pressure the outer wall portion having remained

31

32

clastic, encapulates the inelastica deformed portion producing compressive stress on inner

surface. Compressive prestress by either shot peening of auto frettage alone very often increases

life tenfold. Initial tests of preconditioning by shot peening of auto frettaged component is very

encouraging. Improvement of life for shot peened preconditioning of auto frettage applications

is expected to show life improvement.

Shot peening onto the die casting leads to break down and elongation of grains on its surface. A

plastic deformation layer is formed and sub-surface layer structure becomes more compact

leading to the enhancement of pressure tightness of the part. This process is specially useful for

automobile parts where the die casting is done by injecting molten metal at high pressure and

high velocity into die cavity. The air entered in the die cavity is entrapped in the castings forming

gas holes leading to porosity. This causes leakage of die castings.

Fig.6 Schematic view of Direct Pressure System .

Fig. 7 Centrifugal Wheel Assembly.

Fig. 8 Pneumatic & Airless Shot Peening Process.

Shot Peening Processes

Two methods of propelling shot are widely used in shot peening. One is pneumatic, which

employs a continuous stream of compressed air also known as Air Blast Method and the other is

centrifugal,a motor driven bladed wheel rotating at high speed.

[i] In pneumatic or Air Blast Method three different types of shot peening systems are

generally employed.

a) Inductin Syphon System or Suction System.

b) Inductin - Gravity System or Gravity System

c) Direct Pressure System.

a) In the suction system : Compressed air is directed by an airjet into the nozzle to create a low

pressure, high veloicity air flow in a suction line leading to the blast nozzle. The compressed air

create ventury effect in the suction like that draws shot in the line from a hopper which is the

bottom section of the peening cabinet. Once the shots reach to the nozzle the remaining air

energy propells them against the work with high velocity.

This system is least efficient in quantity of shots moved for Cfm.of air used, and produces relatively

low shot velocities. Where, low intensities are sufficient, it is the least expensive because no

elevation system is required to move the shot over head for gravity feed. Suction system will peen

upwards while gravity fed systems are limited in this respect.

b) Induction Gravity System or Gravity System : With gravity fed systems the shot feed hopper

islocated above the gun and shot flows by gravity down a supply hose to a small hopper on the

gun. A bucket elevator or equivalent means returns the spent shot from the collecting hopper to

the elevated hopper for recirculation. In true gravity systems shot will flow regardless of whether

compressed air is flowing. This system will flow more shot at slightly higher velocities than suction

systems. The unobstructed gravity shot flow is sometimes difficult to obtain in traversing nozzle

systems.

c) Direct Pressure System : Direct pressure system is themost efficient in terms of volume per

unit time of air required per kg. of shot moved. Of the three principalair systems, direct pressure

system produces the highest shot velocity and is the only system that can move shot through long

lances and side shotting, nozzles to peen deep holes. It is also the most expensive system.

In this system, the shot must be contained in a pressure vessel where from it will drop through a

metering orifice into the high pressure air line.

When the operation must be continuous, the pressure vessel will have an upper chamber which

can be alternately vented into atmosphere for filling and pressurized for dropping this charge into

constantly pressurized lower chamber. The lower chamber in turn feeds continuously into the high

poressure air line.

Comparison of Air Blast Systems: These are advantages to each system, depending on the end

use. Direct pressure equipment is said to throw the most positive shots for the lowest consumption

of compressed air.With this equipment, blasting/peening at low pressure is more efficient.The

main disadvantages of system is its intermittent operation.

Suction-induction delivery systems are less expensive and willoperate continuously until the shots

are consumed. They are constructed with less complex apparatus, can throw very large amount

of abrasive and are simpler to maintain than the direct pressure systems.

Suction equipment is used in automated machines where continuous operation is required,

33

34

however, it normally takes more air to throw a given amount of abrasive/shot.If the air supply is

limited, the use of direct pressure unit may be indicated.

Varying shot velocity is observed in both suction and direct pressure systems due to hose and

nozzle discontinuities.Shot from centrifugal wheel does not vary their velocity at constant speed.

[ii] Centrifugal wheel system or Rotoblast : With centrifugal system, the shot is propelled on to

the work surface centrifugally.The shot is fed from the elevated bin by gravity and deflected by a

feed spout into the center of the wheel revolving at high speed,and is accelerated along the

blades and onto the work piece. In practice, the way the shot is fed into the centre of the wheel

and on to the paddle blades determines, how it is distributed when striking the work. Direction of

the shot stream can be controlled by varying the point where shot is fed on the rotating blades

through control cage. Fig.7 shows the components of the centrifugal peening equipment.

Centrifugal wheels are efficient shot throwing devices. They are used where high production is

required and are powered by solid state variable frequency drive units for absolute controlof rpm

and shot velocity. A 20 HP Rotoblast wheel can project 36,000 lbs. of shot per hour. Air nozzle

system would require 420 HP air compressor for the same volume of shot.Shot from Rotoblast

wheels does not vary in velocity and control is a simple matter of dial settings. With centrifugal

wheels velocity imparted to the particle does not diminish as does shot from nozzles and is

effective to distance of 10 ft. or more. This is tremendous advantages of wheel peening.

Projecting all sizes of shot upto 6.4 mm diameter to very high velocities is possible with centrifugal

wheel. Fig. 8 gives comparison between efficiencies of the two processes. Pneumatic and Airless

shot peening process :-

Since large quantity of shot can be thrown with centrifugal wheels, more attention must be paid

to type and location of wear plating.

Centrifugal Peening Process is qualitatively better than Pneumatic Shot Peening Process. The total

blasting area by Centrifugal Blast Process is very high in comparison to the Pneumatic Shot

Peening Process [Please refer Fig. 8]. Due to high production rate, the process is found ultimately

economical.

5) Shot Peening & Alternative Processes : Various processes which can nduce residual

compressive stresses over metal surface are :-

a. Shot Peening.

b. Hammer Peening.

c. Cold Rolling Working.

d. Auto frettage.

Amongst various above processes of inducing compresses, shotr peening has no limitation of

shape and size of the work piece. It iis most efficient compared to others. Hammer peening is time

consuming and not applicable for peening deep holes and intricate shapes. Cold working is

again limited to cylindrical parts only and is not applicable to unsymmetrical sections and

complicated shapes. Auto frettage is suitable for only inside surfades and not for outside surfaces

of components. Thus shot peening is the most efficient and versatile method of production

peening of metal parts which improves their fatigue and stress corrosion resistance appreciably.

36

Introduction

Resin Coated Sand is an economical and excellent material to produce Cores & Molds in Foundry

practices around the globe. To achieve precise dimensions, smooth core surface and defect free

casting, it is highly recommended to employ shell molding/core making process by international

foundry experts. Resin Coated Sands are specially formulated to reduce emissions, smoke and

odor during production of cores and moulds in ferrous and non-ferrous metal casting.

1. Advantages

Ÿ Castings can be produced with close tolerance and with very minimum machining

allowances along with excellent surface finish.

Ÿ It gives an exceptionally high hot strength

Ÿ Gas evolution is very low during pouring

Ÿ It develops uniform build-up with faster rate of cure

Ÿ It is highly resistant to peel back.

Ÿ It is very dry, smooth, and free flowing with good resistance to moisture

Ÿ Exceptionally smooth and excellent surface finish of the casting with no sand fusion

Ÿ Shelf life of the resin coated sand is more than 6 months.

Ÿ Hollow cores can be produced.

Ÿ Lump free sand.

Ÿ High transverse strength.

Ÿ High production with uniform baking of sand.

Ÿ Special fine Resin Coated Sand doesn't require refractory coatings or core paint.

2. Manufacturing Process

Raw Material

Ÿ Dry washed sand having AFS No. 80 - 90,

Additives/Chemicals

Ÿ Spirit (1:1 ratio to Resin)

Ÿ Hexamine (catalyst) (11 - 14 % of Phenolic Resin)

Ÿ Calcium Stearate (release agent) (3.5% of Phenolic Resin)

Ÿ Phenolic Resin (balance percentage)

Ijaz Ali, M. Mubbashir Saeed, Faisal Iqbal , Pervaiz Mahmood (G.M. Foundry, Ravi Autos)

pervaiz.mahmood@raviautos.com

Development of Resin Coated Sand

37

Additive Quantity

Spirit 1.25 liter

Phenolic Resin 1.04 kg

Hexamine 175 gm

Calcium Stearate 44 gm

50 Kg

Resin CoatedSand

SilicaSand

50 Kg

PhenolicResin

1.04 Kg

Siprit 1.25L

Hexamine

175gm %

CalciumStearate

44 gm%

38

3. Methodology

Batch Weight = 50 Kg

There are two major steps involve in production of "resin coated sand”

Quantity of materials for 50 Kg sand preparation

(A) Resin Solution Preparation Steps:

i. Add 1.04 Kg phenolic resin in 1.25 liter Spirit and heat it until Phenolic Resin completely

dissolves in spirit, this process takes 4 to 4.5 hours

ii. Cool it & add Hexamine 175gm (14% of phenolic resin) in the above solution and allow it to

dissolve.

iii. Add Calcium Stearate 44 gm (3.5% of phenolic resin).

iv. Solution is ready.

(B) To prepare a batch of 50 kg resin coated sand:O

i. Set temperature of Sand Coating Machine's temp at 360 C.

ii. Turn 'ON' the Heaters of Coating machine until it achieves the required temperature.

iii. Add 2.5 liter (5%) prepared resin in 50 kg sand.

iv. Operate mixer about 15 - 17 minutes.

v. Before extracting sand turn 'ON' Vibrator, automatically followed by sieving, for breaking

the sand lumps and cooling it which give finally graded, fine sand of homogeneous

quality.

39

vi. Pack sand in plastic bags of 25 Kg each for storing it up to indefinitely time

4. Precautions

1. Pre-coated sand should be kept dry and without exposure to excessive heat, which

causes clumping.

2. Hexamine & Spirit are highly flammable and harmful for health (organic compound)

3. Avoid over baking, agglomeration can result due to this.

4. Resin limits up to 4 to 6%, it will depend upon the size, shape of the Core.

5. Cast iron or SG Iron Dies are recommended for core production by resin coated sand

rather than copper or brass, as ammonia released during curing will cause corrosion.

6. Phenol and ammonia are released during curing, so good ventilation is needed at Core

Shooters Machine.

5. Applications

It's used in automobile foundries (both for ferrous and non ferrous), mainly at Pump and Motor

Casting foundries, Engine Block foundries and other general Engineering Industries.

By using resin coated sand on core shooter machines a wide range starting from very simple

shape to most complex and intricate can be produced with high accuracy and minimum

rejection rate. In addition to excellent surface finish casting can be produced with close

tolerance with very minimum machining allowances.

6. Cost Comparison

i. Imported Cost approx Rs. 45/Kg

ii. Locally manufactured approx. Rs. 25/Kg

That gives almost Rs 20,000 pkr/ton saving.

45000

25000

Cost Comparison: Imported Vs Local (Rupees per Ton)

( Import) Local Developed