On as-built microstructure and necessity of solution treatment in additively manufactured Inconel 939

作     者：Shaikh, Abdul Shaafi Rashidi, Masoud Minet-Lallemand, Kevin Hryha, Eduard 

作者机构：Chalmers Univ Technol Dept Ind & Mat Sci Gothenburg Sweden Electro Opt Syst Finland Oy Lemminkaisenkatu 36 Turku 20520 Finland 

出 版 物：《POWDER METALLURGY》 (粉末冶金学)

年 卷 期：2023年第66卷第1期

页      面：3-11页

核心收录：

学科分类：0806[工学-冶金工程] 08[工学] 

基　　金：Vinnova [2016-05175] Vinnova [2016-05175] Funding Source: Vinnova 

主　　题：Additive manufacturing laser powder bed fusion superalloy Inconel 939 heat treatment TEM microstructure development 

摘      要：Increased adoption of additively manufactured superalloys has led to the consideration of revised heat treatment approaches for these materials. The rapid cooling during additive manufacturing processes has been seen to suppress gamma prime (gamma ) precipitation, which has raised the possibilities for omitting the high-temperature solution treatment step that usually precedes ageing heat treatment for these alloys. In this work, the as-built microstructure of a high gamma prime fraction superalloy Inconel 939 is presented, where the absence of any gamma precipitation is notable. However, transmission electron microscopy shows the presence of nano-sized Eta (eta) phase. It is shown that the omission of solution treatment leads to the growth of the deleterious eta phase upon ageing, which results in embrittlement in tensile loading. It is concluded that at least for this particular alloy the solution treatment plays a critical role in the establishment of the required microstructure and hence cannot be omitted from the heat treatment.