Specific cutting energy employed to study the influence of the grain size in the micro-milling of the hardened AISI H13 steel

Among the miniaturization processes, micro-machining is one of the most used processes in the modern industries. In spite of the high number of micro-machining applications, several gaps should be investigated, such as the size effect. This paper analyzes the influence of the size effect on the specific cutting energy. Workpieces of AISI H13 steel with different austenitic grain size were machined with a tool of 0.5 mm of diameter and coating of (TiAl)N. The input parameters were the cutting speed, feed rate, and radial depth of cut. The responses were the cutting force and specific cutting energy. The results showed that the reduction of the specific cutting energy with the increase of feed rate for small grain sizes corresponded to 73 %. In the same way, the reduction for the large grain size corresponded to 70 %.