新しい超仕上法によるフェライトの加工 (第1報)

加工特性と砥石作業面の検討

抄録

This paper describes a newly developed superfinishing method for finishing ferrites material. It also deals with the fundamental problems of this method. This method is as follows : A metal-bonded wheel is used as superfinishing stone while the solution of CuSO₄ functions as machining liquid, and in the machining process electric current is made to flow from the electrode in the solution tank to the wheel through the flushing machining liquid; as a result the solution plays the roles of both machining liquid and plating solution. The principle of this method may be explained in terms of the penetrating action of abrasive grains into the surface of workpiece. Because the wheel gets plated with copper in the machining process, it gradually achieves the glazing state of its surface with the process of machining. And then the abrasive grains reduce their depth which is penetrated into workpiece as the wheel is put in the glazing state, until at the final finishing stage the surface of the workpiece comes to have small roughness. In the experiment, Mn-Zn single crystal was finished by this method, and the results were compared with those achieved by the ordinary superfinishing method. Investigation was made of how the plating of the wheel influenced the finishing operation. The results obtained are as follows : (1) From finishing characteristics by this method, this finishing type can be regarded as nearly the same as the grazing type in the ordinary superfinishing. (2) The final finishing roughness is 0.02-0.03 μm R_max. (3) The metal-bonded wheel is plated with copper during the finishing process and the penetration depth of abrasive grains is reduced in proportion to the finishing time.