Effect of heating schedule on pore structure and mechanical property of porous TiNi body produced by self-propagating high-temperature synthesis

Porous TiNi body was produced by self-propagating high-temperature synthesis (SHS) method. Control of pore structure and mechanical properties were investigated by varying the heating schedule before ignition. Three types of heating schedule (A, B and C) were used to produce a temperature gradient within the reactant green body of the (Ti+Ni) powder mixture. Pore size was determined by SEM observation and image-analysis. Mechanical properties such as tensile strength, strain and elastic modulus were measured by tensile tests. Phases formed in porous TiNi products were determined by XRD analysis. The porosity of all TiNi bodies produced showed no great variation, i.e. it was in range of 62-64% relative density. However, differences in average pore size were evident. From XRD data, it could be confirmed that TiNi (B2 and B19´) phase exists as the main phase. DSC results showed that all specimens have a shape memory effect