Effect of powder loading on mechanical properties of metal injection molding 17-4PH stainless steel
YU Jian1,2, LI Yimin1,2, LI Dongyang2, LI Xing2
1. Hunan Injection High Technology Co., Ltd, Changsha 410083, China; 2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China
Abstract：The binder composition POM (polyformaldehyde) in the injection molded 17-4PH stainless steel body was catalytically degreased under nitric acid atmosphere, and then thermal degreasing and sintering were carried out in a vacuum sintering furnace. The effects of powder loading and catalytic degreasing time on the catalytic degreasing rate were studied, and the effects of powder loading on the microstructure, density and tensile strength of sintered products were also studied. The results show that the microstructure of the sintered products is composed of austenite and a small amount of ferrite. With increasing the powder loading from 55.1% to 65.7%, the catalytic degreasing rate of the sintered sample decreases from 7.8% to 5.2%; the density increases from 7.56 g/cm3 to 7.66 g/cm3, and the tensile strength increases from 1 076 MPa to 1 204 MPa. With increasing the thermal retention time from 30 min to 90 min at 130 ℃, the catalytic degreasing rate increases from 4.9% to 6.7%. When the thermal retention time in the range of 90-150 min, the catalytic degreasing rate stabilise at about 6.7%. With the powder loading of 65.7%, the POM in the binder can be completely removed by 90min catalytic degreasing. The degreasing rate reaches 87%, and the injection blank forms a complete communicating channel.
喻建, 李益民, 李东阳, 李行. 粉末装载量对金属注射成形17-4PH不锈钢力学性能的影响[J]. 粉末冶金材料科学与工程, 2018, 23(1): 32-37.
YU Jian, LI Yimin, LI Dongyang, LI Xing. Effect of powder loading on mechanical properties of metal injection molding 17-4PH stainless steel. Materials Science and Engineering of Powder Metallurgy, 2018, 23(1): 32-37.
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2018, Vol. 23 
