FRACTURAL BEHAVIOUR OF METALS UNDER LARGE DEFORMATIONS

Abstract

Ever since the genesis of the oldest civilization. it has been first and foremost endeavour of mankind to invent new things for betterment of humanlife and the society as a whole. And, behind all such activities main driving forces were it's unsatiable quest to know more and more and, ofcourse, the necessities of day to day life. Somebody has rightly said - 'Necessity is the mother of Invention'. It was, perhaps, this necessity which led to a journey from the age of, stone to present complex material age, during which engineers and-metallurgists invented and worked upon a large number of materials. In this long history, these people confronted a large number of problems regarding these materials. One of such problems was the amount of workability, defined in simple words as ability of a material to be worked upon to give it required forms, a constant source of frustration for people concerned. It has been observed that materials can fail during metal forming due to ductile fracture, brittle fracture, plastic buckling under compressive forces or due to pick-up of metal on the tooling and it can be well affected by factors like temperature, strain rate, lubrication, die-design, etc. f 11