Micro-Machining of Sculptured Surfaces by Lathe-type Ultra-precision Milling Machine.

Abstract

Micro-machining technology is in general well known in the field of photolithography technique, where most of material to be used are brittle ones such as silicon-oxide. From now on, however, the requirement of producing micro-machine and/or micro-mechanism with metal materials will be increased since a variety of workpiece configurations can be easily made. Thus, the study deals with the micro-machining of metal workpieces with sculptured surface by use of an ultra-precision milling machine newly developed. The lathe-type ultra-precision milling machine, consisting of Z-motion table, positionable spindle on it as C-rotational axis, X-motion table and B-rotational table on it, is equipped with a pseude ball endmill composed of a single crystal diamond tool mounted at the top of high speed air spindle on B-rotational table. Two control programs were developed to carry out 3-axis and 4-axis control micro-machining respectively. 3-axis control program enables the tool to produce a human face-like surface with the surface roughness of 77 nm(Rmax) within the area of 3.5 mm square. On the other hand, 4-axis control is to cope with the machining of workpieces with a steep incline, changing the tool attitude by B-rotational table. The cutting experiment shows the potential of 4-axis control ultra-precision milling of workpieces with a steep incline. As a result, the possibility of generating ultra-precision sculptured surfaces is experimentally confirmed with metal workpieces.