INDUSTIAL VISIT TO BRAHMOS AEROSPACE TRIVANDRUM LIMITED

INDIAN INSTITUTE OF SPACE SCIENCE AND TECHNOLOGY

20th September 2014

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INDEX

NO.

CONTENT

PAGE

1 FOREWORD 2

2 BRAHMOS AT A GLANCE 3

3 NDT 5

4 PRECISION AND GENERAL MACHINE SHOP 7

5 QUALITY CONTROL 9

6 SURFACE TREATEMENT 11

7 APPENDIX 15

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FOREWORD

The AeroClub, Indian Institute of Space Science and Technology (IIST) organized an Industrial

visit to BrahMos Aerospace Trivandrum Ltd. (BATL), on 20th September, 2014 for members of the

Club. Total 19 student members along with 4 faculty members joined this industrial visit. The visit

was organized with the prior permission and guidance of Dr. Praveen Krishna, Assistant Professor,

IIST. Prof. Pradeep Kumar, Prof. Deepu, Prof. B.R. Vinoth and Prof. Satheesh accompanied us

with this industrial visit.

We would like to express our deepest appreciation to Mr. Rajeev Madhvan who continually and

convincingly conveyed the spirit of adventure and guided us throughout the visit explained us every

part of BrahMos. We would like to thank our Professors and Institute without whom the visit

wouldn`t have been a possibility at the first instance.

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BRAHMOS AT A GLANCE

According to the late Edwin Starr, war is good for absolutely nothing. They create havoc and loss to

mankind on a large scale. Wars put pressure on the resources of the country making them work hard

to juice out the maximum from even the little that they possess which tends to accelerate

technological development to adapt tools for the purpose of solving specific military needs. During

the Persian Gulf war, cruise missiles emerged as a key innovation which led India to look forward

in the direction of having its own Cruise missile. As a result in February 1998, the then President of

India A. P. J. Abdul Kalam and Deputy Defence Minister of Russia N.V. Mikhailov signed an inter-

governmental agreement in Moscow to establish BrahMos Aerospace for producing the BrahMos

missiles. The missile is named after two rivers, Brahmaputra of India and Moskva of Russia. First

of all, what is a Cruise missile? It is a guided missile that carries an explosive payload and uses a

lifting wing and a propulsion system, usually a jet engine to allow sustained flight. The Defence

Research and Development Organization (DRDO) of India and the Federal State Unitary Enterprise

NPO Mashinostroyenia (NPOM) of Russia have together formed the BrahMos Aerospace Private

Limited under BrahMos Aerospace. BrahMos Aerospace production centre first started

at Hyderabad in Andra Pradesh. In 2007, BrahMos Aerospace acquired Kerala Hitech Industries

Limited at Thiruvananthapuram in Kerala and converted it into BrahMos Aerospace Trivandrum

Limited which made it into the second missile making unit for a world-class missile facility with

system integration and testing. It is an AS9100 company, highest certificate given to any Aerospace

industry and is the biggest airborne launcher manufacturer in India. The symbol for BrahMos

Aerospace Trivandrum Ltd. shows that the missile is so powerful that it can even break Shivling;

Shivling depicting the epitome of power as per Indian mythology. The missile can be configured for

land, sea and aerial platforms. The technical specifications include:

Maximum range -290km

Maximum velocity Mach -2.5 2.8

Warhead -300kg

Weight -3000kg

Length -8.4m

Diameter -0.6m

Unit cost -US$ 2.73 million

BrahMos is powered by a two-stage propulsion system. A solid propellant booster provides the

initial acceleration and then the liquid-fuelled ramjet system helps it in reaching supersonic cruise

speed. The air-breathing ramjet propulsion is more fuel-efficient in comparison with conventional

rocket propulsion which provides the BrahMos with a longer range over similar missiles powered

by rocket propulsion. The missile follows Fire and forget principle of operation i.e. it has inbuilt

inertial sensors like gyroscopes and accelerometers, GPS and radar which requires no guidance

system after being launched.

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It has the capability of attacking surface targets as low as 10 meters in altitude to as high as 14000

meters. The first BrahMos missile was test fired from the integrated test range at Chandipur in

Orissa Coast in June 2001. After that, missile has been numerous times. In 2004 and 2007, the land

based BrahMos block-1 was tested for Indian army in Pokhran, Rajasthan and then was inducted

into army on June 21, 2007. In 2008, BrahMos Aerospace acquired Indian state-owned firm Keltec

to manufacture and integrate BrahMos components and missile systems. This was necessary to

meet the increased orders received from the Indian Army and Navy. Block II, with advanced

supersonic dive manoeuvrability, has also been developed and was tested in September 2010 from

the Interim test range at Chandipur, Orissa. In December 2010, the BrahMos block-III+ version was

successfully test-fired from the integrated test range at Chandipur, off the Orissa Coast, India.

Brahmos 2, a hypersonic cruise missile with a speed of Mach 7, is under development. Its range is

expected to be 290 meters; keeping in mind that Missile Technology Control Regime prohibits

Russia from helping us in developing missiles with ranges above 300 kms.

BrahMos Aerospace has developed a universal vertical launcher module (UVLM) for the ship-

based BrahMos N1 missile. The UVLM can launch up to eight missiles to destroy a group of

warships featuring modern anti-missile defence systems. An aircraft-launched variant (BrahMos A)

is currently being configured for the Sukhoi SU-30MKI aircraft of the Indian Air Force (IAF). It

features a smaller booster and additional tail fins for greater stability during launch.

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NDT

Non-destructive testing (NDT) is a wide group of analysis techniques used in science and industry

to evaluate the properties of a material, component or system without causing damage. Because

NDT does not permanently alter the article being inspected, it is a highly valuable technique that

can save both money and time in product evaluation, troubleshooting, and research. Common NDT

methods include ultrasonic, magnetic-particle, liquid penetrant, radiographic, remote visual

inspection (RVI), eddy-current testing, and low coherence interferometry. NDT is commonly used

in forensic engineering, mechanical engineering, electrical engineering, civil engineering, systems

engineering, aeronautical engineering, medicine, and art.

BraHMos

Weld verification by X ray Radiography

After welding, visual inspection can detect a variety of surface flaws, including cracks, porosity and

unfilled craters, regardless of subsequent inspection procedures. Dimensional variances, warpage

and appearance flaws, as well as weld size characteristics, can be evaluated.

Moreover for precise flaw detection, Radiography (X-ray) is one of the most important, versatile

and widely accepted of all the non-destructive examination methods - Fig. 1. X-ray is used to

determine internal soundness of the welds.

Fig 1. Radiography

Radiography is based on the ability of X-rays and gamma rays to pass through metal and other

materials opaque to ordinary light, and produce photographic records of the transmitted radiant

energy. All materials will absorb known amounts of this radiant energy and, therefore, X-rays and

gamma rays can be used to show discontinuities and inclusions within the opaque material. The

permanent film record of the internal conditions will show the basic information by which weld

soundness and be determined.

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When X-rays or gamma rays are directed at a section of weldment , not all of the radiation

passes are through the metal. Different materials, depending on their density, thickness and atomic

number, will absorb different wavelengths of radiant energy. The degree to which the different

materials absorb these rays determines the intensity of the rays penetrating through the material.

When variations of these rays are recorded, a means of seeing inside the material is available. The

image on a developed photo-sensitized film is known as a radiograph. Thicker areas of the

specimen or higher density material (tungsten inclusion), will absorb more radiation and their

corresponding areas on the radiograph will be lighter

Radiographic images are not always easy to interpret. Film handling marks and streaks, fog and

spots caused by developing errors may make it difficult to identify defects. Such film artifacts may

mask weld discontinuities. Surface defects will show up on the film and must be recognized.

Because the angle of exposure will also influence the radiograph, it is difficult or impossible to

analyze fillet welds by this method. Because a radiograph compresses all the defects that occur

throughout the thickness of the weld into one plane, it tends to give an exaggerated impression of

scattered type defects such as porosity or inclusions.

Inspection is done using X-rays and gamma rays as a penetrating medium, and densitized film as a

recording medium, to obtain a photographic record of internal quality of weld of the separate parts

of the pressure vessels. Generally, defects in welds consist either of a void in the weld metal itself

or an inclusion (tungsten in the weld strip shown to us) that differs in density from the

surrounding weld metal.

Radiographic equipment produces radiation that can be harmful to body tissue in excessive

amounts, safety precautions like proper uniform and isolation of the room with lead accessories is a

must. All instructions are followed carefully to achieve satisfactory results. Only personnel who are

trained in radiation safety and qualified as industrial radiographers are be permitted to do

radiographic testing.

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PRECISION AND GENERAL MACHINING

Precision machining is a process where material is removed from a component to a very high

tolerance. Precision Instrument Machine Shop is a full-service machine shop specializing in the

custom design and fabrication of mechanical equipment. The temperature of the room is kept at 20

degree celsius so that variation related to temperature does not affect the finish. Precision machines

use a cutter and can be solid cutters such as tungsten carbide, cobalt or HSS. Also Watercutters

were used which are very accurate and use extremely high pressure water.

There are precision type lathes, drilling and boring machines, grinders, gear cutters, and milling

machines. Precision machine tools are classified as machine tools of increased precision ( class P),

high precision ( class H), superhigh precision(class A), and highest precision ( class S). Precision

machine tools make it possible to produce articles of grade of fit 11, with geometrically regular

surfaces, precisely aligned axes, and low surface roughness.

In the Precision machining room, there are around 26 CNC machines which allows to machine

extremely small and accurate features at a sub-millimeter scale. 3 axis as well as 5 axis machines

are available. Drill bits with size as low as 2 mm are used to machine the process. There are

continuous path controllers as well as point to point path controllers helping in making contours of

any shape at any angle. The machining centres, equipped with automatic tool changers, are capable

of changing 90 or more tools. The usual process flow is:

Develop or obtain the 3D geometric model of the part, using CAD. Decide which machining operations and cutter-path directions are required

(computer assisted).

Choose the tooling required (computer assisted). Run CAM software to generate the CNC part program. Verify and edit program. Download the part program to the appropriate machine. Verify the program on the actual machine and edit if necessary .Run the program

and produce the part.

The lab also has Electron Discharge machine where an electrical spark is created between an

electrode and a workpiece. The spark is visible evidence of the flow of electricity. Intense heat is

produced due to this electric spark producing with temperatures reaching from 8000 to 12000

degree Celsius, melting almost anything. The spark is very carefully controlled and localized so that

it only affects the surface of the material. The EDM process usually does not affect the heat treat

below the surface. The spark always takes place in the dielectric of deionized water. The

conductivity of the water is carefully controlled making an excellent environment for the EDM

process. The water acts as a coolant and flushes away the eroded metal particles.

Also water Jet machining, a non-traditional process, where a jet of water at high velocity and

pressure, may be mixed with an abrasive substance like garnet or aluminium oxide, is used to make

intricate shapes The process is essentially the same as water erosion found in nature but accelerated

and concentrated by orders of magnitude. The most important benefit of the waterjet cutter is its

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ability to cut material without interfering with the material's inherent structure as there is no "heat

affected zone" or HAZ. This allows metals to be cut without harming or changing their intrinsic

properties.

Machine shop work is generally understood to include all cold-metal work by which an operator,

using either power driven equipment or hand tools, removes a portion of the metal and shapes it to

some specified form or size. This is the place from where the raw material starts its journey to

become the final product. In launch vehicles used by ISRO, Pressurized tanks are used to store air

at high pressures so as to maintain the flow rate of the liquid propellants. These tanks, alloy of

titanium and vanadium, are manufactured by Brahmos. Initially, two metal plates are made into

semi-circular shapes by mandreal and then electron beam welding is done. In an electron beam

welder electrons are "boiled off" as current passes through a filament which is in a vacuum

enclosure. An electrostatic field, generated by a negatively charged filament and bias cup and a

positively charged anode, accelerates the electrons to about 50% to 80% of the speed of light and

shapes them into a beam. Due to the physical nature of the electrons - charged particles with an

extremely low mass - their direction of travel can easily be influenced by electromagnetic fields.

Electron beam welders use this characteristic to electromagnetically focus and very precisely

deflect the beam at speeds up to 10 kHz. When fast moving electrons hit a metal surface they are

decelerated which transforms the kinetic energy of each individual electron in the beam into

thermal energy in the component. When electrons in a focused beam hit a metal surface, the high

energy density instantly vaporizes the material, generating a so-called key hole. These pressure

vessels are then tested in an underground room for a pressure 1.67 times the approximate pressure.

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QUALITY CONTROL

Quality control (QC) is a procedure or set of procedures intended to ensure that a manufactured

product or performed service adheres to a defined set of quality criteria or meets the requirements

of the client or customer. Quality Assurance (QA)is defined as a procedure or set of procedures

intended to ensure that a product or service under development (before work is complete, as

opposed to afterwards) meets specified requirements.

QC control and BrahMos:

Job Record: Keeps track of the work from its early stage to the following stages including

dimensions and tolerances with geometrical changes and processes involved. Very minute details

like orientation of the material grains in case of supporting structure components are also included

in the job record sheet. After every process the engineer responsible signs at their respective places.

Time taken by each process and consecutive measurements are also mentioned very systematically

in the job record.

Clean room: A clean room is an environment, typically used in manufacturing or scientific

research, with a low level of environmental pollutants such as dust, airborne-

microbes, aerosol particles, and chemical vapours. More accurately, a cleanroom has

a controlled level of contamination that is specified by the number of particles per cubic meter at a

specified particle size. To give perspective, the ambient air outside in a typical urban environment

contains 35,000,000 particles per cubic meter in the size range 0.5 m and larger in diameter.

Following are the standards for cleanrooms:

Table 1. ISO standards of clean room

Maximum concentration limits(paricles/m3) ISO

equivalent 0.1 m 0.2 m 0.3 m 0.5 m 5 m

10 2 ISO 1

100 24 10 4 ISO 2

1000 237 102 35 ISO 3

10000 2370 1020 352 ISO 4

100000 23700 10200 3520 29 ISO 5

1000000 237000 102000 35200 293 ISO 6

352000 2930 ISO 7

3520000 29300 ISO 8

The clean room visited had 1lakh particles per m3.

Digital 2D height gauge: Used to measure linear lengths and PCDs with significant accuracy and

precision. It has several probes for measurement of different works. Calibration required.

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CMM:

A coordinate measuring machine (CMM) is used for measuring the physical geometrical

characteristics of an object. This machine can be manually controlled by an operator or be computer

controlled. Measurements are defined by a probe attached to the third moving axis of this machine.

Probes can be mechanical, optical, laser, or white light. A machine which takes readings in six

degrees of freedom and displays these readings in mathematical form is known as a CMM. Its

advantages include flexibility of measuring dimensions, reduced setup time, improved accuracy,

reduced operator dependency and productive.

A magnificent bridge type CMM was shining in the QC section with air bearings and a set of

probes of all sizes with ruby probes and inductive probes.

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SURFACE TREATEMENT

The processes of surface treatments tailor the surfaces of engineering materials to

control friction and wear,

improve corrosion resistance,

change physical property, e.g., conductivity, resistivity, and reflection,

alter dimension,

vary appearance, e.g., color and roughness,

Ultimately, the functions and/or service lives of the materials can be improved.

Anodising: Anodising is the creation of an oxide layer on the surface of aluminium by electro-

chemical means. This oxide layer protects the underlying metal and prevents further corrosion from

taking place. An additional benefit of this process is that the oxide layer that is created will accept

certain dyes, thus allowing aluminium items to be finished in a wide range of colours.

Fig 2 .A schematic of anodising

Dyeing: Typically the dyes used are organic and can be sensitive to acid from the anodizing process

or contaminants in the rinse water. Therefore, post-anodizing rinsing is critical before parts go into

the dye tanks to avoid contamination of the dye tanks. The pre-dye rinse needs to be a high purity

water rinse such as deionized water and room temperature or cooler water. The use of a heated pre-

dye rinse would begin to seal the pores in the anodized surface and could reduce the dye pickup into

the pores. Depending on the dye, air agitation is either required or forbidden. The dye manufacturer

should be able to provide the best practices for their dyes. The dyeing tanks are typically heated per

the dye manufacturers instructions. The warm dye is drawn into the pores of the anodized layer

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due to capillary action.

Sealing- The sealing operation is the final stage of the anodizing process. Immersion of an anodized

part into hot (boiling point) water causes the pores to seal over due to the slight solubility of the

aluminium oxide of the anodized surface. This provides stain and corrosion protection for a clear

anodized surface and prevents dye migration or degradation in a dyed surface. The hot water used

in sealing also needs to be high purity such as deionized water. Sealing additives are also

sometimes used such as nickel acetate with boric acid. The use of additives requires additional

wastewater treatment.

Some of the techniques performed at BrahMos are discussed below:

Sulphuric Acid Anodising:

Often known as natural, clear or silver anodising, this is the commonest type of anodising, and the

description covers a wide range of processes at different levels. The process differs from hard

anodising in that the electrolyte temperature is higher and the current density employed is lower.

The types of sulphuric acid are sub-divided into classes mainly determined by the field of

application. All anodising processes are sealed unless the film is used as a primer for paint or

adhesives.

Chromic Acid Anodising:

Compared with sulphuric acid anodising, it gives relatively soft, thin coatings, normally of two to

five microns thickness. These are used mainly for electrical insulation and general protection

against corrosion under mild conditions. Unsealed coatings are used as a 'key' for paints and

adhesives. It is light grey in colour, with a very silky texture.

Chromic acid anodising is particularly useful when:

It is necessary to minimise the loss of fatigue strength of workpiece, as compared with sulphuric acid-type processes.

The item to be anodised contains crevices or small blind holes from which it may be difficult to remove electrolyte.

The coating is on metal less than 250 microns thick, the process and resultant coating have less adverse effect upon the properties of the underlying metal.

Components containing crevices or small blind holes.

Pre-treatment for painting, especially in aerospace applications.

Flaw detection - technique for identifying cracks, folds, inter-crystalline corrosion, machining damage, incipient melting of grain boundaries, cold shuts, etc.

In the surface treatment in BrahMos, the layer of chromic gas was less than 10 micron thick as

compared to Sulphuric gas which was nearly 20 micron thick. The temperature of working for

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chromic anodising was 400C and 150C for sulphuric anodising. The systematic steps for the

anodising include Vapour Degreaser Alkaline SoakCaustic EtchingChromic Acid AnodisingHard Chromium PlatingDe-smutting (with citric acid) Dyeing

The dying was done using organic agents by impregnation process.

Chemical Milling:

The chemical milling process utilizes chemicals rather than cutting tools to etch shapes in metal.

Depending on the design of the part and desired volume of parts necessary, chemical milling can be

an economical machining option, and it is regularly employed for a wide number of applications.

Tooling for chemical milling is relatively simple, as it is generated using CAD software, with little

to no need for replacement parts. Additionally, the process does not alter the structure of the

remaining metal, which occurs in a variety of other physical machining processes. However, the

process is only suitable for metals of relatively limited thicknesses, except in situations where only

etching is required. At BrahMos chemical milling was used to contour a complex skin panel

section. Several layers of material were removed to make slots and geometries.

The process of chemical milling begins with a CAD file, which is sent to or produced by

the fabrication service (according to customer specifications). Once received, the fabricator creates

a graphic representation of the file, which will map the pattern on the top and bottom surface of the

metal to be milled, and selects the type of metal to undergo the process. Before any other steps can

be performed, the metal must be thoroughly prepared and cleaned for the application of photo-resist

material. After the metal is cleaned, the photo-resist material is applied to both sides, then

developed using UV light and chemicals. The remaining photo-resist material maps the areas that

will be removed by the application of acid, which is then sprayed on the coated part. After the acid

has been given sufficient time to work, the component is removed from the chemical milling area

and the layer of photo-resist material is removed.

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APPENDIX

Table 2. List of students in the visit

SR. NO. NAME OF THE STUDENT

1 AKHIL JAISWAL

2 AMAL JYOTHIS

3 AMAN GUPTA

4 AMIT KAMBOJ

5 DIVESH SONI

6 GAURAV VAIBHAV

7 J. YUDHISHTR

8 MANIMARAN SAMAR

9 MANISH KUMAR MISHRA

10 MARIYA RATLAMI

11 MAYANK KUMAR

12 MOFEEZ ALAM

13 MOHD. AHMAD

14 RAHUL TANWAR

15 RAJEEV VARMA

16 RAMAN CHAWLA

17 SREEAJ VARMA

18 SWAPNIL KUMAR

19 TANMAY SINGHAL

Table 3. List of Contacts in BATL

SR no CONTACT PERSON

1 Shri. Rajeev Madhavan Manager

BATL

2 Shri. Sunil Kumar Deputy GR

BATL

Table. 4 List of faculty members for visit

SR no Faculty name

1 Dr. Praveen Krishna

2 Dr. Pradeep Kumar P

3 Dr. Deepu M.

4 Dr. Satheesh K

5 Dr. B.R. Vinoth