Effects of Sintering Variables on the Physical and Mechanical Properties of Metal Injection Molding Molded 17-4 PH Stainless Steel

Abstract

Metal injection molding (MIM) is a near net shape manufacturing technique for producing small, complex, precision parts in mass production. MIM process is manufacturing method that combines traditional shape-making capability of plastic injection molding and the materials flexibility of powder metallurgy. The process consists of the following four steps: mixing of metal powder and binder, injection molding to shape the component, debinding to remove the binder in the component, sintering to consolidate the debound parts. In this research, the physical and mechanical properties of metal injection molded 17-4 PH stainless steel were investigated with the variation of sintering temperatures (1300 °C - 1360 °C) and atmosphere conditions (argon and vacuum conditions). The relative density, microstructure, distortion, and hardness are measured and analyzed in this study. The results show that highest relative density of 87%, relative homogeneous shrinkage and high hardness are achieved by sintering at 1360 °C for 1.5 hours and argon atmosphere. At the same sintering temperature and time, sintering in vacuum shows lower relative density (81%) than that in argon condition due to pores growth. The pore growths were not observed in the argon atmosphere. It can be concluded that sintering stages more rapidly under vacuum condition. The hardness measurements result also showed that high hardness is obtained by high density parts. The optimum average hardness obtained in this study is 239 HV. However, the hardness properties results are still lower than 280 HV according to MPIF Standard 35 for MIM parts.

Comparative study on the properties of 17-4 PH stainless steel parts made by metal fused filament fabrication process and atomic diffusion additive manufacturing

“…High heating rates induce large thermal stress, increase the porosity and make finer the grains, while a slow heating rate favours the coarsening of grain, decreasing the mechanical properties (Afian and Subuki, 2012). The sintering atmosphere plays a fundamental role during the process to modify the density and mechanical properties of the parts in 17-4 PH as reported by Shieddieque et al (2021) and Baba et al (1995). The use of H 2 -atmosphere reduces oxides generated at high temperature.…”

Pengaruh Variasi Temperatur Sintering pada Proses Metal Injection Molding Terhadap Densitas, Porositas, dan Kekerasan Sinter Part Berbahan SS 17-4 Ph

“…Namun, produk MIM memiliki rentang kerapatan relatif dari 98-99%. Hasil densitas relatif rendah mungkin disebabkan oleh tekanan injeksi rendah selama proses cetakan pemadatan (Shieddieque et al, 2021).…”

Characterization of Barium Hexaferrite (BaFe₁₂O₁₉) from NitrateCompound with Sol-Gel Method for Barium Hexaferrite MagneticMaterials

“…Magnets are advanced materials that are vital to various advanced technological applications, serving as key components in converting kinetic energy into electricity and vice versa, such as in automotive, electronics, and energy sectors [3]. One of the most commonly used permanent magnets in Indonesia and around the world is Barium Hexaferrite (BaFe12O19), which is a type of ceramic magnet with a hexagonal structure known for its excellent quality and reasonable stability, allowing it to be applied in various technology applications [4], [5].…”