The maximum reduction per pass during wire drawing of an aluminium alloy ignoring friction and redundant work is $$77\% $$. The strain hardening exponent of the material is ______________.

In an open die forging, a circular disc is gradually compressed between two flat plates. The exponential decay of normal stress on the flat face of the disc, from the center of the disc towards its periphery, indicates that

A moving mandrel is used in

In a rolling process, the state of stress of the material undergoing deformation is