Evaluation of bimodal microstructures in selective-laser-melted and heat-treated Ti-6Al-4V

Autor: Tom McKenna, Charles Tomonto, Greg Duggan, Eoin Lalor, Seamus O'Shaughnessy, Daniel Trimble
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Materials & Design, Vol 227, Iss , Pp 111700- (2023)
Druh dokumentu: article
ISSN: 0264-1275
DOI: 10.1016/j.matdes.2023.111700
Popis: As-built, SLM-printed Ti-6Al-4V parts suffer from non-equilibrium, brittle microstructures due to the formation of metastable α’-phase martensite as a result of the printing process. Post-processing heat treatments are required to alleviate residual stress and decompose the martensite into equilibrium phases. Using unconventional ‘cyclical’ heat treatment profiles, it is possible to achieve a bimodal microstructure as opposed to a more typical lamellar microstructure achieved using conventional heat treatment profiles. In the present research, the effect of cyclical heat treatment parameters (maximum temperature, minimum temperature, number of cycles and cooling regime) on the grain morphology, phase composition and mechanical performance (static and dynamic) has been evaluated. Furthermore, a comparison to a typical lamellar microstructure has been completed as a reference.
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