Shear strain induced formation of nanostructured pure metals

Chip formation is of fundamental importance during the formation of nanostructured pure metals. Poor chip control leads to chip build-up and an uncontrollable surface roughness. The use of chip breaking is arbitrary because of the mechanics of chip curl is not well understood. The causes of chip curl and chip flow are still the subject of intense discussion and research among plasticity researchers. The subject originally focused on cutting forces and on the conditions at the chip-tool interface using soft plastic metals. The increasing speed of cutting has focused researchers to look at chip breaking after the chip has been cut. In the first instance, chips were considered to be continuous, discontinuous and continuous with a built-up edge. The theories of metal cutting allow one to predict the forces and stresses in the chip during formation but do not tell us anything about the strain within the chip, unless a computational approach is used. This paper describes the mechanics of chip formation using the grinding process at the microscale and explains how the deformation of the grinding grains affects shear strain rates and the average grain size in the cut chip.