Ability of the composite 50 Ti-47 Ni-3 Cu to transform heat energy into mechanical work upon cyclic temperature change

The TiNiCu alloy with a shape memory which may be used as a working medium for the martensite engine converting heat energy to mechanical one is studied for its energy characteristics. Mechanical characteristics of the material are studied under torsion of cylindrical specimens of stressed thermocycling through temperature intervals of martensite transformations. It is established that the shape memory and transformation ductility effects determining serviceability and power of the martensite engine, vary gradually with the number of heat changes reaching saturation after 10-15 thermocycles. The heating-and-cooling stress dependence of deformations due to the shape memory and transformation ductility effects also varied with the number of heat changes. Cooling conditions under stress of 50 MPa and heating conditions under 200 MPa and above proved to be most optimal. Serviceability of the engine made of the TiNiCu alloy exceeds 10MJ/m**3 and its power reaches 10**5MW m** minus **3 under operation frequency of 10**3 Hz.