Experimental investigation of porous metal materials in high-speed micro-milling process

Porous stainless steels, which have recently extended to the microscale domain, have been widely used for biomedical materials because they have good strength-to-weight ratio and superior corrosion resistance. Most components fabricated from porous materials still require secondary machining despite being produced in near-net shapes. However, they have poor machinability. High cutting force, high cutting temperature, poor surface integrity, and severe tool wear are encountered in the machining process of the difficult-to-cut porous materials. This article focuses on the micro-cutting performances and effects of cutting parameters in the micro-milling of porous stainless steel materials, including tool wear patterns and mechanism, effects of tool wear and cutting parameters on surface topography, cutting force, and cutting temperature. Comparative experiments were performed to investigate surface burr and cutting performances of porous materials in the micro-milling process. The effects of machining parameters on porous stainless steels in micro-milling are studied. Furthermore, a preliminary relationship of cutting parameters with micro-milling force and milling temperature is also established. The tool wear patterns and mechanisms were observed. Based on the findings, this article concluded that tool wear influences the surface morphology of the machined part and the effects of structural porosity on the cutting process during the micromachining of porous materials.