A Comparative Investigation of the Porous NiTi Alloys Synthesized by Self-Propagating High-Temperature Synthesis and Combined Process of Decomposition and Sintering

Abstract

Porous NiTi alloys were successfully synthesized by two different processes, including self-propagating high-temperature synthesis (SHS), and a combined process of decomposition – sintering. A systematic comparison of micro-structures and mechanical properties of these alloys was investigated. The results showed that the SHS process was better than decomposition – sintering process. By controlling the processing parameters of SHS, the received porous NiTi alloys showed that the porosity and pore were larger, and ratio of opened-pore reached up to 80%. The porous NiTi alloys fabricated by SHS process also exhibited good properties, such as a high compressive strength (up to 250MPa), and elastic modulus in range of 6.1 – 7.0GPa. The porous NiTi alloys synthesized by decomposition – sintering process have lower porosity (26-43%), lower compressive strength (< 110MPa), lower elastic modulus (< 1.2GPa) but the strain could be reached to 10%.