Work

Effect of sintering temperature on microstructure, phase evolution, thermo-mechanical properties of spark plasma sintering of NiTi alloy

Year: 2025

Type: article

Abstract: This study examines the significant effects of sintering temperatures on the microstructure and the thermal, mechanical, and dynamic mechanical properties of NiTi alloys . The compaction of polycrystalline Ni50Ti50 (at.%) powders via spark plasma sintering (SPS) at various temperatures. The starting powder, with a particle size of 20 to 63 μm, was compacted at a fixed pressure of 50 MPa. Our findings indicate that the consolidated alloy exhibits stable phases of NiTi, such as austenite and martensite, at different sintering temperatures . Notably, both compactness and hardness improve as the sintering temperature increases. Higher temperatures lead to decreased porosity, resulting in a denser structure with a chemical composition of Ni 47.1 Ti 52.9 (at.%). The grain size distribution also narrows with increased temperatures, highlighting microstructural evolution . Moreover, the samples displayed remarkable shape memory behavior and exceptional thermo-mechanical properties, achieving a maximum compactness of 99.8 % at 1150 °C. This research thoroughly investigates the influence of sintering temperature on microstructural characteristics , phase transformations, and shape memory behavior, underscoring the potential of NiTi alloys for various applications.

Source: Surface and Coatings Technology

DOI: 10.1016/j.surfcoat.2025.132152