Temperature-dependent thermal properties of a shape memory alloy/MAX phase composite: Experiments and modeling

A shape memory alloy/MAX phase composite, namely NiTi/Ti3SiC2 composite, was fabricated using spark plasma sintering at 1233 K under 100 MPa for 8 min, from a NiTi/Ti3SiC2 powder mixture with a 50/50 v/v ratio. The thermal diffusivity was measured at both ambient and elevated temperatures up to 1224 K using a laser flash analyzer. The specific heat at constant pressure was measured over the temperature range 300-600 K using a differential scanning calorimeter. The thermal conductivity was then calculated from the thermal diffusivity, specific heat and density. To validate the experimental results, a survey of data on the thermal diffusivity, specific heat and thermal conductivity of monolithic NiTi and Ti3SiC2 was carried out. Finite-element modeling of a micromechanics-based representative volume element was carried out to predict the thermal conductivity of the NiTi/Ti3SiC2 composite. An agreement between the experimental and finite-element results was found.