Question

a: is friction desirable in the forging process. yes or no? how we can minimized it ?

b: consider an elastomer such as rubber. this material shows large elastic defrmotion before failure can this matrial be forged ? give resons

c: in forging opration does the power requirment decrease in the final steps ? give reosons

Answer 1

a: No, friction is not desirable in forging as it leads to poor surface finish and also results in increase surface temperature resulting in poor die life.

We can minimise it by lubricating so that normal pressure or shear stress will be transferred to the thin lubricating oil film.The oil film will support the normal pressure.

b: Forged rubber is prepared by chrome in making sneakers by appling 300 degree celsius temperature and pressure.

c:At first power requirement is large but at the end by lowering power, internal strain can be controlled as at the end when workpiece cools faster it become stronger and less ductile which may induce cracking if deformation continues.