Study on the Microstructure and Mechanical Properties of SUS-316L Stainless Steel by Adding TaC Powders Through a Metal Injection Molding Process

• Main Authors: Po-Yao Chang, 張博堯
• Other Authors: 張世賢
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/vka3y3

碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 106 === SUS-316L is a kind of austenitic stainless steel with has great corrosion resistance, making it one of the mostly used materials. It can satisfy general electronic parts requirements for magnetic property, corrosion resistance and appearance. However, SUS-316L stainless steel often cannot meet the requirements expected in regard to its mechanical properties. Metal Injection Molding (MIM) is a relatively new production method that can make a product with higher density and increased strength. Therefore, this study utilized the Metal Injection Molding (MIM) process to improve the sintered density and mechanical properties by adding TaC powder. In the present research, different ratios of metal powder and binder (93:7 and 92:8 wt%) were mixed and underwent various sintering at 1340°C, 1360°C, 1380°C and 1400°C, respectively. Moreover, the follow-up research added different ratios of TaC powders (1, 3 and 5%) to improve the properties of SUS-316L stainless steel. Finally, the mechanical properties and microstructure were inspected. The experimental results showed that the mixing ratio of 93:7 wt% of the metal powder and binder, and sintered at 1380°C possessed the optimal properties. Meanwhile, the sintered density was 7.65 g/cm3, hardness was HV0.5 134, tensile strength and elongation reached 540 MPa and 22%, respectively. In addition, TaC powders proved helpful in inhibiting grain growth (20.89 → 13.75 µm). Significantly, the optimal properties were obtained by adding 5 wt% TaC powder. The sintered density increased to 7.89 g/cm3, with hardness enhanced to HV0.5 170, while tensile strength and elongation increased to 548 MPa and 25%, respectively. Consequently, according to the above discussion and experimental results, the addition of TaC powder in SUS-316L stainless steel can effectively improve the microstructure and mechanical properties.