Milling force model for asymmetric end-mills during high-feed milling on AISI-P20

Abstract

ABSTRACT Manufacturing molds for plastic parts injection are a particular machining domain, where challenging materials, like AISI P20 steel, are forced to satisfy the highest surface quality requirements. Before mirror polishing, milling operation is a common and challenging task due to drilling and milling with the same tool. Thus, special cutting tools, like asymmetric indexable type, are often used. This tool presents two geometrically equal positive inserts – one placed horizontally and the other vertically – for the flexible machining of holes, cavities, floors, and walls. Rough-medium milling operations lead to a complicated relationship between cutting conditions and geometrical tool parameters, making it challenging to balance the tool life of both inserts. The novelty of this work is to propose a model for cutting force prediction with an asymmetric tool to explain the separated behavior of both inserts and determine a better compromise between cutting conditions and tool life. The experimental tests were done for model validation and then wear cutting tests for testing improved cutting conditions. The results predicted by the model proved that by changing the depth of cut from 0.3 mm to 0.8 mm, the wear in both inserts was more balanced, increasing chip volume up to 1.7 times.