Recovery of Scratch Grooves in Ti-6Al-4V Alloy Caused by Reversible Phase Transformations

Autor: Artur R. Shugurov, Alexey V. Panin, Andrey I. Dmitriev, Anton Yu. Nikonov
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Metals, Vol 10, Iss 10, p 1332 (2020)
Druh dokumentu: article
ISSN: 2075-4701
DOI: 10.3390/met10101332
Popis: The deformation behaviors of Ti-6Al-4V alloy samples with lamellar and bimodal microstructures under scratch testing were studied experimentally and using molecular dynamics simulation. It was found that the scratch depth in the sample with a bimodal microstructure was twice as shallow as that measured in the sample with a lamellar microstructure. This effect is attributed to the higher hardness of the sample with a bimodal microstructure and the larger amount of elastic recovery of scratch grooves in this sample. On the basis of the results of molecular dynamics simulation, a mechanism was proposed, which associates the recovery of the scratch grooves with the inhomogeneous vanadium distribution in the β-areas. The calculations showed that at a vanadium content typical for Ti-6Al-4V alloy, both the body-centered cubic (BCC) and hexagonal close-packed (HCP) structures can be more energetically favorable depending on the atomic volume. Therefore, compressive or tensile stresses induced by the indenter could facilitate β→α and α→β phase transformations, respectively, in the vanadium-depleted domains of the β-areas, which contribute to the recovery of the Ti-6Al-4V alloy subjected to scratching.
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