January 17, 2016
Journal Article

Stress assisted removal of conjugation boundaries in non-modulated Ni-Mn-Ga by coordinated secondary twinning

Abstract

Observations, obtained by in-situ straining and conventional TEM, of the Mullner-King mechanism of transformation by coordinated secondary twinning are presented. 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 nearly23°. The orientation evolves over a region behind the transformation front about 100 nm in extent.

Revised: December 15, 2015 | Published: January 17, 2016

Citation

Muntifering B.R., L. Kovarik, N.D. Browning, R.C. Pond, W.B. Knowlton, and P. Mullner. 2016. Stress assisted removal of conjugation boundaries in non-modulated Ni-Mn-Ga by coordinated secondary twinning. Journal of Materials Science 51, no. 1:457-466. PNNL-SA-109808. doi:10.1007/s10853-015-9236-1