The Structure and Physical-Mechanical Properties of Multicomponent Porous TiNi (Mo, Fe, Cu) Alloys

The copper alloying effect on the special features and physical-mechanical properties of multicomponent porous TiNi- base alloys has been investigated. A partial replacement of Ni by 1−10 at.% Cu in a porous TiNibase alloy is shown to produce changes in the phase composition of the material and to give rise to dendritic regions. The behavior of each of the materials under study with addition of Cu as an alloying element depends on the size and distribution density of precipitate particles and dendrites. The change in the structural state of porous TiNi-base alloys with Cu additions due to Ti- and Ni-rich phase precipitation and formation of dendritic regions is found to bring about changes in the physical-mechanical properties of the materials over a wide temperature interval. Optimum copper concentrations were fixed to be in the range from 3 to 6 at.%. With these concentrations, the porous alloys of the above-indicated composition exhibited a wide working temperature interval (0−40°C) over which reversible deformation developed and martensite shear stresses were of very low magnitudes.