Flashless forging

flashless forging

1. Seminar on SEMINAR ON FLASHLESS FORGING By Name-Anirudh kumar Regd no- FF16M15 Sub- Near N et Shape Process Branch-FFT Batch-2016-18

2. INTRODUCTION FORGING:- Forging is a Bulk Deformation Process in which the work is compressed between two dies to get a useful required shape According to the degree to which the flow of the metal is constrained by the dies there are three types of forging: Open die forging Impression die(closed die) forging Flash-less forging

3. Types of forging Open die forging:- work is compressed between two flat dies, allowing metal to flow laterally without constraint Closed die forging:- D ie contains a cavity or impression that is imparted to workpiece , thus constraining metal flow - flash is created

4. Flashless forging It is true closed die forging in which metal deformed in a die cavity permits virtually no excess metal to escape During this process the preform is totally enclosed in the die cavity so that no flash is formed In actual practice, a thin fin or ring of flash may form in the clearance between the upper punch and die. This can be easily removed by blasting and doesn’t require a trim die.

5. This process carried out in an elevated temperature which in between cold and hot forging. Work pieces are heated only to the level at which the metal flows just enough, under forging pressure, to fill the die but not so freely as to extrudes from closing die halves before the cavities are filled. This process is usually accomplished in one or two process.

6. Preform design aspects Preform or blank weight :- T o achieve complete filling of the cavity without developing extreme pressures Metal volume should be controlled accurately. A small increase in volume will cause tremendous increase in load, die stress, die wear. A decrease in volume, die will not fill completely. Preform dimensions should be controlled accurately as it will be enclosed completely in die. Preform and tooling temperatures:- To get high forge-ability the process can be carried out in an isothermal forging operation where the die and punch temperature is same as that of preform thereby it control the thermal expansion and forging pressure

7. Process requirement These are normally produced at a very high rate so usually preferred where large production volume required. To achieve this process requirements are:- The preforms, or blanks must be equal in weight Each preform must be heated to the same temperature Proper positioning of billet inside the die

8. Benefits from flashless forging over closed die forging Material waste:- in closed die forging operation, flash averages 15-30% of original work piece. But Flashless forging uses 100% of stock. Energy waste:- heating metal that will become flash, transporting it, and then deforming it expends energy for no useful purpose. Production time:- flash formation creates undesirable internal structures in forging. Better control of grain flow is achieved in flashless forging as it eliminates the grain flow that lies at 90⁰ to the free surface as in close die forging. Flash t rimming operation and equipment used in flash forging also again adds up cost and production time.

9. Advantages Material and energy saving No de-flashing operation Reduction of subsequent machining work through smaller machining allowances and as a result of lower tolerances of blank material Higher dimensional accuracy Higher production rate Higher strength and integrity as internal grain structure follow flow of metal within the part Produced part are in net shape

10. D isadvantage Higher tooling cost due to complex die shape Requirement of high volume accuracy of blank (deviation <5%) and thus in increased demand in blank production The process requires a careful mass distribution

11. Flashless forging process need more careful die design particularly for non-symmetrical part in comparison to conventional impression die forging process. So the process lends itself best to part geometrics that are usually simple and symmetrical . Parts produced are:- Components for automative transmission Tracks in military vehicles Special piston for racing cars Aerospace components Connecting rod

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