Abstract
In this study, the characteristics of grain boundary step generation in practical ultraprecision cutting opreration of Al-Mg alloy are experimentally made clear by analyzing height of grain boundary step, crystal direction, surface finish, residual stress and so on. Especially, crystal direction of each crystal grain of Al-Mg alloy appearing on finished surface is decided by ECP (Electron channeling pattern) method, and relationships between crystal orientation and height of grain boundary step are investigated. Main conclusions obtained in this study are as follows : (1) The height of grain boundary step on finished surface increases with a closen crystal orientation to (1 2 4) on the stereographic projection of crystal direction of Al-Mg alloy. (2) The height of grain boundary step or the surface finish decrease with a decrease of clearance angle of cutting tool. So a cutting tool with a smaller clearance angle results in finer machined surface.
