超精密切削過程のシミュレーション解析 (第1報)

単結晶切削過程の単純せん断面模型による解析

抄録

An ultra-fine machining is a key technology for obtaining a product with fine dimensions and surfaces. As a surface characteristic is greatly affected by cutting mechanism and/or chip formation, it is very important to predict the phenomenon. At an ultra-fine machining, a dimension of undeformed chip thickness is less than that of crystal of work material. A cutting may be seen to be carried out for single crystals with random orientations. The paper discusses about the cutting mechanism on single crystal material, and about the problems for predicting the cutting mechanism. Through the observation and quantitative measurements of cutting forces, friction angle on tool rake face etc. of fine cutting in SEM, the following results were obtained. The flow type chip is generated for any direction of single crystal. The shear angles, however, are greatly affected by the direction of crystal and the friction angle on rake face also, which depends on the direction and on the rake angle too. The alternation of shear angle depending on the direction can be predicted based on either slip theory of crystal or anisotropic plastic theory, when the friction angle for any direction is in hand. In order to predict a shear angle, a friction angle on rake face must be discussed.