Process factors and improvement measures affecting surface roughness in precision parts processing

In the process of precision parts machining, the residual area caused by the geometric shape and cutting motion of the cutting tool, the grooves scratched by the accumulated debris adhering to the cutting edge, the vibration ripples caused by the vibration between the workpiece and the cutting tool, and the extrusion and friction marks caused by the wear of the tool back surface form roughness on the surface of the parts. The process factors that affect surface roughness mainly include workpiece material, cutting amount, tool geometric parameters, and cutting fluid.

Generally, elastic-plastic materials with higher toughness have higher surface roughness values after processing, while elastic-plastic materials with lower toughness are prone to obtaining lower surface roughness values after processing. For the same material, the larger the grain structure, the greater the machined surface roughness value. Therefore, in the process of precision parts machining, in order to reduce the surface roughness value, the material is often quenched and tempered or normalized before cutting to obtain uniform and dense grain structure and larger hardness.