Study on characteristics of SiCp/Al composites during high-speed milling with different particle size of PCD tools

Abstract

SiCp/Al composites contain a large amount of SiC particles as reinforced phase, and the particles are hard and brittle. So tool wear is quite serious in the cutting process. Polycrystalline diamond (PCD) tools are the most effective tool material for achieving high-speed and precision cutting of SiCp/Al composites. In this paper, PCD tools were used in high-speed milling SiCp/Al composites with higher volume fraction and larger size SiC particles. The wear resistance and wear mechanism of PCD tools were studied when the diamond particle sizes were 5, 10, 25, and 32 μm, respectively. Moreover, the variation characteristics of cutting force and machined surface roughness were investigated. The results showed that the size of diamond particle had a great influence on wear resistance of PCD tools. During high-speed milling SiCp/Al composites with high volume fraction and larger particle size, the larger the particle size of diamond particles were, the worse the wear resistance of PCD tools were. With the increase of diamond particle size, the flank wear increased, and the degree of micro-chipping of cutting edge deepened slightly. The values of cutting force and machined surface roughness were both smaller, when diamond particle size of PCD tools was 5 μm. There was hardly variation of machined surface roughness in the whole cutting process. In other words, the tool wear had little impact on the machined surface roughness.