Improvement of Machining Performance using Hybrid Rotary Ultrasonic Milling (HRUAM) for Hardened D2 Tool Steel Materials

This paper demonstrate the effectiveness of Hybrid Rotary Ultrasonic Assisted Milling (HRUAM) technique in improving the machining performance for AISI D2 tool steel material. The high strength of these materials (>50 HRC) contribute to its poor machinability ratings. Some of the common problems in dealing with this material are roughed machined surface, high machining force, high cutting temperature and rapid tool wear. Experimental investigation to compare between HRUAM and conventional machining for different set of parameters namely cutting speed, feed rate and machining depth on the surface roughness value has been done to confirm the effectiveness of the proposed technique. Taguchi Orthogonal array design with 3 factors was used as a design matrix for analyzing the effect of each parameter. The experimental results indicated that the surface roughness was improved from 1.81 m (conventional) to 0.19 m (HRUAM) almost 89.50 % improvement in the same cutting condition. In addition, from ANOVA result indicated that speed, feed rate and vibration frequency are the most dominant factor affecting the surface roughness value. The findings from the deliberately conducted experiments can be used for improving the production time and cost in mold fabrication by eliminating the manual polishing process.