Micro rotary ultrasonic machining

Rotary ultrasonic machining (RUM) is a hybrid machining process capable of machining advanced engineering materials like ceramics, Ti-alloys, glass, quartz, structural ceramics, and silicon carbide at macro level. RUM employs the synergistic effect of material removal mechanisms of ultrasonic machining and diamond grinding. This paper explores the feasibility of downscaling RUM to achieve micromachining of brittle materials. Challenges encountered during the downscaling of RUM at a micro level, and methods used to resolve the same are explained. An in-house built test bed was used in this micro RUM feasibility study. Using micro electro discharge machining (micro EDM), the micro tools required for micro RUM were fabricated in-house, from a commercial macro tool made of polycrystalline diamond (PCD). Several process parameters influencing micro RUM have been identified. Experiments reveal that tool diameter, abrasive size, and static load are the major factors influencing the material removal rate. Except pitting, no other form of tool wear was observed in this feasibility study of micro RUM using PCD tool.