Stress-Assisted Removal of Conjugation Boundaries in Non-Modulated Ni–Mn–Ga by Coordinated Secondary Twinning
Observations are presented, obtained by in situ straining and conventional TEM, of a transformation mechanism by coordinated secondary twinning predicted by Mullner and King. The material studied is the martensitic phase of a non-modulated Ni–Mn–Ga alloy, which exhibits a microstructure comprising domains of lamellar matrix/twin composites. Straining these specimens induced lamellar domains to transform into their conjugate counterparts. In this process, secondary twinning generates a change of misorientation between the matrix and twin lamellae of the initial domain by nearly 23°. The orientation evolves over a region behind the transformation front about 100 nm in extent.
Muntifering, B.; Kovarik, L.; Browning, N. D.; Pond, R. C.; Knowlton, W. B.; and Müllner, P.. (2016). "Stress-Assisted Removal of Conjugation Boundaries in Non-Modulated Ni–Mn–Ga by Coordinated Secondary Twinning". Journal of Materials Science, 51(1), 457-466. http://dx.doi.org/10.1007/s10853-015-9236-1