Local deformation mechanisms of two-phase Ti alloy

T. S. Jun; G. Sernicola; F. P. E. Dunne; T. B. Britton

Materials Science and Engineering A 649 (2016) 39-47

This paper describes a study of local deformation mechanisms in two-phase Ti alloy, Ti-6Al-2Sn-4Zr-2Mo, by performing in-situ micropillar compression tests. A colony microstructure was examined and select grains identified for examination were chosen with EBSD measurements. These grains were chosen to isolate individual slip systems within each test. Micropillars of tri-crystal (α-β-α) structure were fabricated from four determined regions, and compression tests were performed using a displacement-controlled nanoindenter set inside a SEM, with a constant displacement rate. The results show that the α/β morphology significantly affects the local deformation behaviour. For these colony structures, Schmid’s law in general enables anticipation of local slip activity, but the presence and morphology of the β phase can significantly alter the apparent yielding point and work hardening response. The role of interfaces within these tri-crystal pillars is discussed.

DOI: https://doi.org/10.1016/j.msea.2015.09.016