Study on Mechanical and Thermal Expansion Properties of Oxide Coated Magnesium Borate Whiskers Reinforced Aluminum-based Composite

Abstract

The surface of magnesium borate whiskers was coated with oxide coatings of different components by chemical precipitation method, and magnesium borate whisker-reinforced aluminum-based composites were prepared by squeeze casting method. The compressive deformation resistance of the prefabricated whisker and the tensile and thermal expansion properties of the composite were tested. The experimental results show that the oxide coating can effectively improve the anti-deformation ability of the whisker preform, and the whisker preform prepared by MgO and Al2O3 coating has better strength, and the compressive strength at room temperature reaches 0.98 MPa and 0.96 MPa. The composite material prepared by Al2O3 coated whiskers has the highest room temperature tensile strength of 263 MPa, and the composite material prepared by ZnO coated whiskers has the lowest room temperature tensile strength of 224 MPa. The thermal expansion curve of the composite material shows that as the temperature increases, the thermal expansion coefficient of the composite material gradually increases, and the thermal expansion coefficient of the composite material decreases slightly after a temperature cycle.