Influence of TiN nanoparticles on the microstructure and properties of W matrix materials prepared by spark plasma sintering

Abstract

W–(0.5, 1, 2, 4)wt.% TiN composite powders were formed by mechanical alloying for 5h and sintered by spark plasma at 1800°C. The effect of TiN nanoparticle content on the microstructure and properties of the composites were investigated by scanning electron microscopy, transmission electron microscopy, tensile test, microhardness test, and thermal conductivity test. With the addition of TiN ranging from 0.5wt.% to 4wt.%, SEM analysis results showed that TiN was distributed homogeneously and W grains were refined by TiN. The fracturing of pure W was intergranular, whereas cleavage fracture appeared in the W–TiN composites and increased with increased TiN content. The density was found to initially increase and then decrease with increased TiN content. The same trend was observed for the thermal conductivity. Microhardness increased with increased TiN content. The tensile strength reached 180MPa when the content of TiN was 2wt.%. Furthermore, the mechanical properties of 2wt.% exceeded those of other alloys at different TiN weight percentages.