Effect of phase transformation on ductility of additively manufactured Co–28Cr–6Mo alloy: An in situ synchrotron X-ray diffraction study during mechanical testing

Autor: J.J. Hoyos, Eduardo Bertoni da Fonseca, Miloslav Béreš, R. Maciel Filho, A.L. Jardini, P.F. da Silva Farina, L.H.M. Antunes, Eder S.N. Lopes
Rok vydání: 2019
Předmět:
Zdroj: Materials Science and Engineering: A. 764:138262
ISSN: 0921-5093
DOI: 10.1016/j.msea.2019.138262
Popis: The influence of strain-induced martensitic transformation on the mechanical properties of a Co–28Cr–6Mo alloy produced using the direct metal laser sintering additive manufacturing technique was analyzed. Both the as-built and solution heat-treated (ST) specimens were subjected to conventional tensile tests. Furthermore, X-ray diffraction spectra were simultaneously acquired using a synchrotron light source. In addition, electron backscatter diffraction analysis was performed on the specimens before and after tensile testing. Both techniques revealed the occurrence of the strain-induced γ-face-centered cubic → e-hexagonal close-packed phase transformation. The higher microstrain and preferential grain orientation of the as-built specimen favored the onset of the phase transformation. Moreover, the ductility of the ST specimen was significantly higher than that of the as-built specimen. This behavior was attributed to the isotropic properties of the randomly-oriented and equiaxed grains, increase in resistance to necking, and reduction in internal stresses caused by the solution heat treatment.
Databáze: OpenAIRE
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