夹杂物对粉末冶金FGH97合金显微组织与力学性能的影响

Effect of Inclusions on Microstructure and Mechanical Properties of Powder Metallurgy FGH97 Alloy

采用夹杂物含量水平不同的两批次粉末,通过相同的热等静压制度制备了FGH97合金,研究了夹杂物对FGH97合金力学性能的影响。对比测试了两组粉末制备FGH97合金的拉伸性能,表征了粉末特征、合金组织、拉伸断口。结果表明,采用真空惰性气体雾化(Vacuum induction melting gas atomization,VIGA)法制备的粉末,细粉收集率高,制备的合金晶粒细小,容易引入夹杂物。富Si的异常颗粒夹杂会使合金中产生贫γ′区,影响粉末间的结合,降低FGH97合金的塑性。热等静压态的FGH97合金室温延伸率为9.5%,650℃的延伸率为1%。FGH97合金经过固溶+时效热处理后,基体中的贫γ′区消失,FGH97合金的塑性得到显著提升,FGH97合金室温延伸率提升至14.25%,650℃的延伸率提升至6%。

Two batches of powders with different levels of inclusion were prepared by the same hot isostatic pressing regime to produce FGH97 alloy,and the effect of the difference in the content of inclusion on the mechanical properties of FGH97 alloy was studied.The tensile properties of FGH97 alloys were tested,and the powder characteristics,alloy microstructure,and tensile fracture morphology were characterized.The results show that,the powder prepared by vacuum induction melting gas atomization(VIGA)method is denoted as powder,which has the characteristics of fine powder collection rate,small grain size of prepared alloy and easy to introduce inclusions.The abnormal particle inclusion of Si-rich will lead to the formation of poorγ′zone in alloy,affects the bonding between powders and reduces the plasticity of FGH97 alloy.At hot isostatic state,the FGH97 alloy has an elongation of 9.5%at room temperature and 1%at 650℃.FGH97 alloy was heat treated by solid solution+aging heat treatment,the poorγ′zone in the matrix disappears,and the plasticity of FGH97 alloy is significantly improved,the room temperature elongation of FGH97 alloy is increased to 14.25%,the elongation at 650℃is increased to 6%.