An Investigation into the Mechanisms of B2-NiAl in the Thermal Conductivity and Mechanical Properties of Light Duplex Steel

In this work, the microstructure, mechanical properties and thermal conductivity of the xNiAl/Fe−20Cr-15Ni-6Al-2Mo (x = 0, 10, 20, 30 wt.%) prepared by mechanical alloying and vacuum hot-pressing sintering were investigated. The experimental results revealed that the primary phases of the material after NiAl addition were the austenite phase, ferrite phase and B2-NiAl phase. The addition of B2-NiAl significantly improved the thermal conductivity of the materials, especially when the NiAl content was 30 wt.%, and the thermal conductivity at room temperature was 16.91 W/(m·k), which was 67.59% higher than that of the matrix material. As the NiAl content increased, the tensile strength and elongation after fracture of the materials first increased and then decreased. The 20 wt.% NiAl material had excellent values of 1215.41 MPa and 6.09%, which were 106.76% and 53.40% greater than that of the matrix alloy.