17-4PH stainless steel as a with high strength and resistance to corrosion of stainless steel materials, medical devices, automotive industry, manufacturing industry, military industry, aerospace industry and nuclear industry is widely used, but due to precipitation hardening and high hardness really makes the alloy become difficult to machining. In order to overcome the problem of machining, metal powder injection molding technology is considered to be the best alternative for the manufacture of 17-4PH stainless steel. Some previous studies have shown that the use of MIM to produce 17-4PH stainless steel material has obvious advantages. But on 17-4PH stainless steel powder injection forming the actual application process, due to the problems caused by improper processing parameters of injection defects, solvent debinding and insufficient strength, deformation of thermal debinding, sintering body surface finish of poor. In this paper, the technology of metal injection molding 17-4PH stainless steel was studied from two aspects of metal injection molding process parameters optimization and binder optimization. Research results show that:
Control of injection parameters on the injection process of green defects, bending strength and the green body conformal has important influence. In 147 C of injection temperature, pressure 8.5MPa, rate of 70%, Paul pressure time 1.5s and cooling time of 20s condition could be obtained without defects, higher flexural strength and shape preserving good injection blank. In the process of solvent skim, with the increase of the temperature of the solvent, the decrease of the body thickness and the ratio of the surface area and volume of the sample, the speed of the. In addition, the dynamic process of solvent extraction was studied, and the kinetic parameters of different temperature were obtained. Through the TGA curves of binder and feedstock make the thermal debinding process can be obtained without defects thermal debinding and body, the thermal debinding and mechanical properties with the highest thermal debinding temperature raise and improve. In 950 DEG C, the tensile strength 117.71MPa, flexural strength 104.81MPa. The highest temperature and sintering temperature have a certain degree of matching. The 900 degree of thermal strength of the sintered body has the highest mechanical properties, the tensile strength is 1538.57MPa, the tensile strength is 1164.12MPa. During the sintering process, the tensile strength increases with the increase of holding time and the highest temperature, and the tensile strength of the sintered compact is highest at the highest sintering temperature of 1350 degrees C and thermal insulation 60min, which is 1481.35MPa.
