Exploration of a micron and mesoscale steps/slots composite manufacturing technology based on thin-film compensation

Abstract

The geometrical characteristic of micron and mesoscale parts/structures is within 0.01–10 mm. However, it is challenging to ensure machining accuracy by using traditional methods. This paper proposed a new composite manufacturing technology of combining precision cutting with film compensation, i.e., a method of subtractive manufacturing followed by additive manufacturing, which can not only achieve high machining quality of micron and mesoscale parts/structures, but also endow the surface with excellent wear resistance and high hardness given by the film. In this work, a multilayer diamond-like carbon (Ti-DLC/α-C:H)n was selected as the compensation film, while the steps and slots with design dimensions of 400 μm and 700 μm were set as the final processing objectives. The tolerance theory of the composite manufacturing technology, including dimensional tolerance of micron and mesoscale, process tolerances of precision machining and measuring, and film thickness tolerance, was investigated. The results showed that after precision cutting and (Ti-DLC/α-C:H)n compensation, the surface hardness of the steps/slots increased from HV775.96 to HV1016.34, while the wear resistance was significantly improved with the friction coefficient reducing from 0.75 to 0.08. Additionally, the steps and slots were processed successfully with a primary size of 400 μm and 700 μm, achieving IT5 machining accuracy.