Inconel 718合金粉末热等静压成形及其影响因素

Hot Isostatic Pressing and Influencing Factors of Inconel 718 Alloy Powder

采用无坩埚感应熔炼超声气体雾化法(Electrode induction melting gas atomization,EIGA)和真空惰性气体雾化法(Vacuum induction melting gas atomization,VIGA)制备Inconel 718预合金粉末,随后采用热等静压工艺制备Inconel 718合金。研究制粉工艺、粉末粒度及包套结构对Inconel 718合金显微组织和力学性能的影响。研究结果表明,EIGA粉末具有更好的球形度,成形合金力学性能优于VIGA粉末;综合考虑力学性能、得粉率等因素,选择15~106μm粒度范围的粉末作为热等静压用粉末;包套壁厚的增加对作用在粉末上的有效应力产生屏蔽作用,空腔体积变化对致密化过程影响较小;粉末填充过程的长时间振动会导致粉末发生粒度偏析,需要控制粉末填充过程的振动频率和振动时间。

Inconel 718 pre-alloy powder was prepared using the electrode induction melting gas atomization(EIGA)and vacuum induction melting gas atomization(VIGA)methods.Inconel 718 alloy was prepared using hot isostatic pressing(HIP).The effects of milling process,powder particle size,and capsule structure on the microstructure and mechanical properties of Inconel 718 alloy were studied.The results show that EIGA powder has better sphericity,and the mechanical properties of the forming alloy are better than those of VIGA powder.Considering the mechanical properties,powder yield and other factors,the powder with particle size range of 15-106μm was selected as the hot isostatic pressing powder.The wall thickness of the capsule has a shielding effect on the effective stress acting on the powder.The change of cavity volume has little effect on the densification process.Long term vibration during the powder filling process can lead to particle size segregation,and it is necessary to control the vibration frequency and time during the powder filling process.