Nucleation of the R martensite in titanium nickelide

Transmission electron microscopy was used to investigate the R martensite nucleation in binary alloys based on titanium nickelide. A heterogeneous nucleation of R martensite crystals at coherent particles of the Ti 3 Ni 4 aged phase, oxide Ti 4 Ni 2 O x particles, at dislocations, and in the field of elastic stresses caused by Ti 3 Ni 4 particles was found and described. The process of growth of an R martensite crystal formed at a Ti 3 Ni 4 4 particle is described. It was shown that, at coarse Ti 3 Ni 4 particles that lost their coherency with the B2 matrix, the B19' martensite was formed.