It was found that copper powder after 20h of milling shows the formation of a number of mechanical twins. The observed twins belong to two types: multiple twins and high-order ones.It is suggested that Venables model ...It was found that copper powder after 20h of milling shows the formation of a number of mechanical twins. The observed twins belong to two types: multiple twins and high-order ones.It is suggested that Venables model on mechanical twins in face-center-cubic metals is reasonable in this case. The generation of mechanical twins could be explained as follows:the shear stress (P_(max)) induced by ball milling exceeds the critical shear stress for twinning(τ):the grain size decreases to a critical value below which twinning rather than slip is the preferred mode of deformation as well as the strain rate induced by ball milling is high.展开更多
文摘It was found that copper powder after 20h of milling shows the formation of a number of mechanical twins. The observed twins belong to two types: multiple twins and high-order ones.It is suggested that Venables model on mechanical twins in face-center-cubic metals is reasonable in this case. The generation of mechanical twins could be explained as follows:the shear stress (P_(max)) induced by ball milling exceeds the critical shear stress for twinning(τ):the grain size decreases to a critical value below which twinning rather than slip is the preferred mode of deformation as well as the strain rate induced by ball milling is high.
