MARTENSITE TRANSFORMATION IN TI-CR BINARY ALLOYS

The details of the martensite reaction have been investigated by thin foil electron microscopy techniques in high purity Ti-Cr binary alloys containing 2.4-5.9 at. % Cr. The morphology and the sub-structure of this martensite has been compared with the massive martensite structure that is typical of the quenched condition in pure titanium. The experimental observations for both the acicular and the massive martensite are in qualitative agreement with the crystallographic theory of the martensite transformation. It is pointed out that the crystallographic theory must be generalized to account for more than one mode of lattice invariant deformation such as the twinning on more than one {101̄1} twin plane that has been observed within a single martensite plate. © 1969.