Microstructure evolution and mechanical response-based shortening of thermal post-treatment for electron beam melting (EBM) produced Alloy 718

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:820

Article

Goel, Sneha¹  Zaninelli, Enrico²  Gundgire, Tejas¹  Ahlfors, Magnus³  Ojo, Olanrewaju⁴  Klement, Uta⁵  Joshi, Shrikant¹ 

[1] Univ West, Dept Engn Sci, S-46186 Trollhattan, Sweden

[2] Univ Modena & Reggio Emilia, Dept Engn Enzo Ferrari, I-41100 Modena, Italy

[3] Quintus Technol AB, S-72166 Vasteras, Sweden

[4] Univ Manitoba, Dept Mech Engn, Winnipeg, MB R3T 5V6, Canada

[5] Chalmers Univ Technol, Dept Ind & Mat Sci, S-41296 Gothenburg, Sweden

关键词: Additive manufacturing;    Electron beam melting;    Alloy 718;    Post-treatment;    Microstructure evolution;    Mechanical properties;   

DOI  :  10.1016/j.msea.2021.141515

来源: Elsevier

【 摘 要 】

Electron beam melting (EBM) produced Alloy 718 was subjected to thermal post-treatment involving hot isostatic pressing (HIPing) and heat treatment (HT). Subjecting the material to HIPing at 1120 degrees C led to significant densification. Study of microstructure evolution during HT (comprising of solution treatment and aging) showed possibility of significantly shortening the HT duration, particularly the time for two-step aging from the standard (8 h + 8 h) long cycle to possibly a shortened (4 h + 1 h) cycle. Another approach for shortening the post-treatment cycle by integrating the HIPing with HT inside the HIP vessel was also successfully implemented. The above observations were further substantiated by tensile response of the material subjected to the varied post-treatment cycles; out of all the post-treatments steps, tensile behaviour was observed to be mainly affected by the aging treatment. Further prospects for shortening the post-treatment protocol are also described, such as shortening of HIPing duration for the typical 4 h to 1 h cycle as well as possible elimination of solution treatment step from the entire post-treatment protocol specifically when prior HIPing is performed. Heat treatment with prior HIPing was found to be crucial for improving fatigue life, because subjecting EBM Alloy 718 to only HT, irrespective of the short or standard long protocol, rendered inferior fatigue response.

【 授权许可】

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