Microstructure evolution and mechanical response-based shortening of thermal post-treatment for electron beam melting (EBM) produced Alloy 718
Journal article, 2021

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 °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.

Additive manufacturing

Mechanical properties

Alloy 718

Post-treatment

Microstructure evolution

Electron beam melting

Author

Sneha Goel

University West

Enrico Zaninelli

University of Modena and Reggio Emilia

Tejas Gundgire

University West

Magnus Ahlfors

Quintus Technologies AB

Olanrewaju Ojo

University of Manitoba

Uta Klement

Chalmers, Industrial and Materials Science, Materials and manufacture

Shrikant Joshi

University West

Materials Science and Engineering

0025-5416 (ISSN)

Vol. 820 141515

Driving Forces

Sustainable development

Subject Categories

Materials Engineering

Applied Mechanics

Metallurgy and Metallic Materials

Areas of Advance

Production

Materials Science

DOI

10.1016/j.msea.2021.141515

More information

Latest update

6/21/2021