Abstract
This paper presents current progress in high performance machining research on die and mold manufacturing. This work is being conducted at the Engineering Research Center for Net Shape Forming (ERC/NSM) for a number of manufacturing companies and covers: a) theoretical and experimental studies of tool failure and tool life in high speed milling of hard materials, b) optimization of CNC programs by adjusting spindle RPM and feed rate (program OPTIMILL) to maintain nearly constant chip load in machining sculptured surfaces, and c) prediction of chip flow, stresses and temperatures in the cutting tool as well as residual stresses in the machined surface layer. Experimental studies are conducted using a 4-axis HMC with 14,000 rpm spindle and 40 m/min feed rate. Tool materials evaluated for tool life and failure include carbides, coated carbides, and PCBN. Workpiece materials investigated include H13 at 46 HRC, P20 at 20 to 40 HRC, and cast iron. Predictions of temperatures and stresses are made using the expanded capabilities of a commercially available FEM code, developed for the analysis of large plastic deformations.