Papers by Author: Wayne N.P. Hung

Abstract: This paper investigates the material removal rate (MRR) in electro discharge micromachining (micro-EDM) of zirconia. Experimental investigation is carried out with 800 μm diameter tungsten electrode with two varying parameters rotational speed and gap voltage. The MRR data are analyzed and an empirical model is developed using Design Expert software. The optimum parameters for maximum MRR are found to be 375 rpm rotational speed and 80 V gap voltage.

Abstract: This paper discusses burr formation in micromilling of AISI 304 stainless steel. Chip load, cutting speed and the application of coolant were chosen as the milling parameters. Experiments were conducted using 500 µm diameter tungsten carbide end milling tool. Milling parameters and measured burr height values were analyzed and statistical models were developed for the estimation of burr height. The models showed that the chip load and cutting speed both have direct and interactive contribution to burr formation. When micromachining without coolant, the burr height increases about 40% compared to that of machining with coolant. The optimized values of chip load and cutting speed were found to be 1 µm/tooth and 78 mms-1 respectively. The predicted burr heights were 5-7% larger than that of measured values.