STRUCTURE, PHASE COMPOSITION, AND CHARACTER OF FRACTURE OF SINTERED TiC-NiTi COMPOSITE MATERIALS.

There are three ranges of compositions in which sintering is controlled by different mechanisms: 0-30% NiTi, in which solid-phase sintering predominates; 40-60%, in which recrystallization through a liquid phase takes place; and 70-90%, which is characterized by a regrouping of carbide particles. The structure consists of TiC, NiTi, and Ni//3Ti phases. As the composition of NiTi changes during sintering, the damping ability imparted by the martensitic transformation occurring during fracture deformation manifests itself only in alloys with less than equivalent to 30% TiC. The character of fracture of TiC-NiTi alloys depends on their binder content and microstructure.