Experimental study on SiCp/Al composites with different volume fractions in high-speed milling with PCD tools

摘要

The single-tooth milling cutter with diamond grain size of 5 mu m was used for high-speed milling silicon carbide particle-reinforced aluminum matrix (SiCp/Al) composites with larger SiC particles and different volume fractions. The volume fractions of SiC particles were 15, 25, 30, and 56%, respectively. The effects of volume fraction of SiC particles on tool wear morphology and wear resistance were analyzed in this paper. The effects on cutting force and machined surface roughness were also studied. The results show that it has little effect of volume fraction of SiC particles on the tool wear morphology, but it has a great effect on the variety of wear amount and wear rate. When SiCp/Al composites wit h low volume fraction are machined, the tool wear amount of polycrystalline diamond (PCD) tools is small and increase slowly. When workpiece with high volume fraction is machined, the tool wear amount increases significantly with the increase of cutting distance. The measured cutting force changes differently when SiCp/Al composites with different volume fractions are machined at high speed. In the initial cutting period, there is little influence of volume fraction on the cutting force component. However, the influence becomes significant with the increase of cutting distance. The machined surface roughness with different volume fractions is larger and has a certain fluctuation in the initial cutting stage. When the cutting distance increases to a certain extent, the surface roughness decreases and tends to be steady. All in all, the surface roughness is larger when the volume fraction of SiC particles is higher.