Influence of Workpiece Hardness on Tool Wear in Profile Micro-milling of Hardened Tool Steel

Machining of engineering metallic materials on micro-level is very complicated. Micro-milling with solid tools, as one of microengineering technologies, is an acceptable process to machining of complex metallic micro-parts. The main problem in micro-milling is sensitivity of cutting tool, due its suppleness and short tool life, and its influences to workpiece accuracy and quality. In this paper is experimentally investigated tool wear of micro-milling tool. During machining tests, influence of workpiece hardness and process parameters is evaluated. Workpiece was cold work alloyed tool steel X155CrVMo12, hardened to different hardness 45, 54 and 63 HRc. Cutting tool was carbide ball-end micro-mill with TiAlN coating, and diameter of 0.6 mm. For different combination of input parameters, tool wear curves is presented, and signification of input parameters on tool wear is evaluated and discussed.