Title screen

[References: 42 tit.]

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 Я-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 Я?a and a?Я phase transformations, respectively, in the vanadium-depleted domains of the Я-areas, which contribute to the recovery of the Ti-6Al-4V alloy subjected to scratching.