Wear Characterization of Cemented Carbide Multipoint Cutting Tool Machining AISI 4140 at High Cutting Speed: Criteria for Materials Selection

The subject covered in this paper concerns the development of an innovative PVD coated multipoint cutting tool with cemented carbide brazed inserts for high-speed cutting of ferrous alloys. The aim of the researchwas to optimize the properties of the constituent materials in order to maximize their durability and provide a constant level of surface finishing of the machined parts. The results concerning the selection of the best cemented carbide grade for high-speed cutting application are presented in this work; both mixed and plain grades were considered. The optimal grade of cemented carbidewas chosen by comparingmicrostructural and mechanical properties such as hardness and toughness with wear resistance in sliding condition against AISI 4140 pins on a pin on disc tribometer. After a proper design of the optimal tool geometry, tools were tested on a CNC milling machine and tool wear was characterized by optical and electronic microscopy.