Thermal Debinding Process of SS 17-4 PH in Metal Injection Molding Process with Variation of Heating Rates, Temperatures, and Holding Times

Abstract
Generally, metal injection molding (MIM) method utilizes SS 17-4 PH as material for application of orthodontic bracket. One of the process of MIM is thermal debinding, which binder is eliminated by thermal energy. In this study, thermal debinding process is conducted with variation of temperature, i.e. 480, 510, and 540°C, holding time, i.e. 0.5, 1 and 2 hours, heating rate, i.e. 0.5, 1, 1.5, and 2°C/min.The effect of temperature shows that the increased temperature will result in the mass reduction percentage due to formation of oxide on the sample, which will be proven through TGA testing. The highest mass reduction was 6.4137 wt% which was obtained at 480°C. For the variation of holding time, the longer the holding time will result in increased mass reduction and the highest mas reduction was 6.255 wt% which was obtained during 2 hours of holding time. For the heating rate, the slower the heating rate will result in increased mass reduction and decreased the presence of crack formation. The best variable was obtained at heating rate of 0.5°C/min, which resulted mass reduction of 6.2488 wt% and less crack formation.