Fettling of CastingFoundry technology

Innovative assignment

Prepared by:11bme050

Introduction

Fettling Processes

Case study

IntroductionGeneral meaning of fettling:

• Mostly used for the words related to cleaning,

polishing, and maintaining systems so that they

will be functional or will remain functional.

• The word itself is derived from a root word

referring to “condition,” as seen in the phrase

“in fine fettle,” which is meant to describe good

condition, shape, or health.

DEFINITION:

Fettling is the means by which a crude casting is turned into a cost effective quality component that meets all the standards required by the customer.

• In context with the casting process, fettling means the removal of unwanted metal, e.g. flashings, risers etc.

• It can include processes like chipping, grinding, shot blasting etc.

Fettling process

• It involves the removal of the cores, gates,sprues, runners, risers and chipping of any ofunnecessary projections on the surface of thecastings.

• Fettling operations can be divided intodifferent stages

FETTLING OPERATIONS

Knocking dry sand cores

Removal of gates & riser

Removal of fins and unwanted projections

Knocking of dry sand core

• Knocking out of dry sand cores. Dry sand coresmay be removed by knocking with iron bar.

• For quick knocking pneumatic or hydraulicdevices are employed, this method is used forsmall, medium work. For large castings thehydro blast process is mostly employed.

REMOVAL OF GATE AND RISER

With chipping hammer

By using cutting saw

Flame cutting

With abrasive cut off machine

By using chipping hammer

• It is particularly suited in case of grey iron castings and brittle materials. The gates and risers can easily be broken by hitting the hammer.

Simple chipping hammerPnumetic chipping hammer

With cutting saw• These saws may be hand saw and power saw

are used for cutting the ferrous like steel, melable iron and for non ferrous materials except aluminum.

• Mostly the hand saws are used for small and medium but when power and used for large work.

HAND SAW

POWER OPERATED SAW

With flame cutting

• This type of method is specially used for ferrous materials of large sized castings where the risers and gates are very heavy.

• In this the gas cutting flames and arc cutting methods may be employed.

• big casting.jpg

With abrasive cut of machine

• These machines can work with all metals but are specially designed for hard metals which can not be saw or sheared & also where flame cutting and chipping is not feasible

Removal of fins, rough spots and

un wanted projections

• The casting surface after removal of the gates may still contain some rough surfaces left at the time of removal of gates. Like. .

• Sand that is fused with surface.

• Some fins and other projections on the surface near the parting line.

• They are needed to be cleaned thoroughly before the casting is put to use.

CNTD.

• The fins and other small projections may easily be chipped off with the help of either hand tools or pneumatic tools.

• But for smoothing the rough cut gate edges either the pedestal or swing frame grinder is used depends upon the size of castings.

CLEANING

TUMBLING

• Traditional and old process.

• Casting is put in a chamber and rotated with 60-70 rpm speed in presence of small pieces of white cast iron

MODERN BLASTING PROCESSES

Blast Machine

• SHOT BLASTING

• TUMBLING WITH HYDRO BLAST

• AIR BLASTING