Abstract

Porous bronze materials manufactured by powder metallurgy require further machining to improve the surface quality and shape accuracy. However, conventional machining with carbide tools and PCD tools can lead to serious pore failure problems. In this paper, monocrystalline diamond (MCD) tools were used to carry out the milling experiments on porous bronze at different machining parameters. The pore area and diameter of the machined surface were used statistically to analyze the effect of different machining parameters on the pore structure during the cutting process. For the porous bronze exhibiting different removal patterns from other materials during the experiments, a novel porous cutting model based on random powder particles was created to verify that the pore structure significantly altered the cutting mechanism of the bronze material at different cutting depths. The experimental results showed that the cutting speed also had a great influence on the porosity, due to the positive strain rate effect of the bronze material, while the influence of feed rate was relatively small. During the cutting process, the material was extruded and rubbed by the cutting edge arc and tool flank face, causing the material to flow into the nearby pores, leading to a decrease in surface porosity. The conformed porosity of the machined surface demonstrates that CNC machines with MCD tools can meet the machining requirements of porous bronze and solve the pore blockage problem in porous materials. This provides a technical reference for the choice of processing methods for porous plastic materials.