Effect of AlN on microstructure, mechanical and thermophysical properties of NiAl/Fe based alloys prepared by vacuum hot-pressing sintering

The effect of AlN content on the microstructure and mechanical properties of NiAl/Fe-x AlN (x = 0, 3, 5, 10, 15 wt%) alloys were investigated after mechanical alloying with subsequent vacuum hot-pressing sintering. The results showed that the AlN reinforced NiAl/Fe alloy contained B-2-ordered NiAl phase, Fe phase and AlN phase. As the AlN content increased, the density of the material decreased gradually, and the hardness and thermal conductivity increased greatly. NiAl/Fe based alloys with 5 wt% AlN obtained higher compressive strength and Rockwell hardness. When the content of AlN was 15 wt%, the density was 5.42 g/cm(3), which was 18.6% lower than that of NiAl/Fe alloy. When the content of AlN was 5 wt%, the hardness reached the maximum value of 59.5 HRC, which was 69.04% higher than that of NiAl/Fe alloy. The thermal conductivity of the material first increased and then decreased with the increasing AlN content. When AlN content was 10 wt%, its thermal conductivity was higher than others at each temperature, and the maximum was 34.75 W/(m.k) at 600 degrees C in the study.