Thermal expansion, electrical conductivity and hardness of Mn3Zn0.5Sn0.5N/Al composites

Abstract

Mn3Zn0.5Sn0.5N/Al composites were successfully prepared by sintering at 623 K and 723 K. It is found that the thermal expansion of Al is effectively decreased with the addition of negative thermal expansion material Mn3Zn0.5Sn0.5N, which plays the role of the thermal expansion compensator in the composite system. The thermal expansion of composites can be tailored by adjusting the volume fraction of Mn3Zn0.5Sn0.5N. In particular, 40 vol.%-Mn3Zn0.5Sn0.5N/Al composite sintered at 723 K has a low thermal expansion coefficient of 2.38×10−6 K−1. The thermal expansion of Mn3Zn0.5Sn0.5N/Al composites matches well with those calculated from the rule of mixture (ROM) estimation. The ROM model can be used to predict the thermal expansion of Mn3Zn0.5Sn0.5N/Al composite and design Mn3Zn0.5Sn0.5N/Al composite with a particular thermal expansion. Mn3Zn0.5Sn0.5N/Al composites exhibit excellent electrical conductivities at the level of 104 S/cm. The hardness of the as-prepared composites increases by adding Mn3Zn0.5Sn0.5N in Al.

Keywords

• electrical properties
• metal-matrix composites
• sintering
• thermal properties