Some Investigations on the Surface Roughness in Silumin Machining

Abstract

The facing tests with the ranges of cutting speeds 10∼1450 m/min have been conducted on disc type silumin, which is an eutectic aluminium alloy containing 13% silicon and is not easy to obtain a good cutting surface in the aluminium alloy, in order to investigate the influence of cutting conditions on surface roughness. In addition, the obtained results are comfirmed by orthogonal cutting tests for the purpose of clarifying the machining mechanism of the alloy system. In this experiment, when the cutting speed is over 600 m/min, the cut surface is good and shows nearly the theoretical roughness calculated by the feed, the tool nose figure and the others. When the cutting speed is less than 200 m/min, especially 90 m/min, the cut surface is very poor because of the vigorous growth of built-up edge. In an intermediate cutting speed range, 300∼600 m/min, a good cut surface is obtained in the orthogonal cutting test, but no satisfactory result is obtained in the facing test owing to influence by side flowing and burnishing and in the latter case, the growth of built-up edge is not distinct by orthogonal cutting or facing.