| Summary: | 碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 104 === Metal injection molding (MIM) is applicable in manufacturing products of complex parts at reduced cost. Because metal injection molded parts undergo 10% to 20% shrinkage during sintering, controlling the dimension change of part in MIM is of an important issue. The purpose of this study is to investigate the effects of debinding time and sintering temperatures on MIM SUS316 parts. This study employed catalytic debinding method, in which HNO3 were used as the catalyst to help decompose binder into CH2O for exhaustion. The gas generated by the binders exhausted through the connected pores when sintering. This work set five different debinding times: 30 to 180 minutes and four sintering temperatures: 1300~1365°C, to understand the effect of debinding time and sintering temperatures. Experimental results showed that, using 98% concentrated nitric acid to debind for shorter than 45 minutes, bubbles and cracks appear on the surface of parts after sintering due to the gas entrapped inside the parts. By debinding in 98% HNO3 for 60 to 80 minutes and sintering, parts with density of 7.6~7.8 g/cm³ are produced which approaches the 7.90 g/cm³ theoretical density. The shrinkage was uniformly 13-14 % for length, width and thickness direction. The 1300~1365°C sintering temperatures had no significant effects on the amount of shrinkage. However, the density apparently increases with sintering temperature. The hardness, tensile strength, and corrosion resistant properties are shown to increase with sintering temperature.
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