Influence of the reinforcement phase of MAX phase composites during ultra-precision grinding

This study investigates various configurations of a MAX phase composite (Ti3SiC2 + TiC) concerning their machinability within the context of mold manufacturing for Precision Glass Molding (PGM). The composite material is machined using ultra-precision (UP) grinding. The aim of this research is to understand the achievable roughness through this manufacturing process, as well as the wear behavior of the grinding tools, depending on the material configuration - specifically the volume percentage (vol.-%) of the TiC reinforcement phase. Using a confocal microscope, surface roughness parameters, including Sq and Sa, were chosen to quantitatively assess surface accuracy. Furthermore, tool wear was monitored by a microscope camera. Due to the novelty of this material, there is a lack of existing knowledge regarding its UP grinding characteristics; hence, various grinding tool configurations and process parameters are varied in the experiments. The findings indicate that surface roughness is not significantly influenced by the material composition (vol.-% TiC). A ductile machining process can be achieved by maintaining a critical chip thickness, regardless of the chemical composition. Consequently, the experiments demonstrate that surface roughness values of Sq < 5 nm are attainable, satisfying the surface quality requirements for applications in precision glass molding. However, the results of the wear tests show that the material composition has a significant influence on the tool wear.