BN与LPSO相混杂增强的镁基复合材料制备及性能

研究了六方氮化硼(h-BN)颗粒增强镁基复合材料的制备工艺及其性能。通过化学镀法在h-BN颗粒表面包覆一层纯镍,镀镍处理能显著改善h-BN与镁合金熔体的润湿性,改善其与基体的界面结合。通过向基体合金中加入Y元素,利用镀镍层熔入熔体中的Ni获得了由Mg-Ni-Y组成的LPSO结构(长周期堆垛有序结构),制得了h-BN+LPSO混杂增强的镁基复合材料。超声处理后,hBN增强相体积分数为3%的镁基复合材料热导率为99.92W/(m·K),室温(RT)至100℃的平均热膨胀系数为18.36×10^-6K^-1,抗拉强度为171MPa,伸长率为3.9%,获得了兼具较高力学性能和优异热物性能的镁合金材料。

Preparation and Properties of BN and LPSO Hybrid Reinforced Magnesium Matrix Composite

The preparation process and properties of hexagonal boron nitride(h-BN)particle reinforced magnesium matrix composites were investigated.A thin layer of pure nickel was coated on the surface of h-BN particles by electroless plating,which can significantly improve the wettability between h-BN and magnesium alloy melt and strengthen the interface bonding with the matrix.By adding Y element to magnesium alloy and consume Ni element fused with the nickel-plating layer,the long period stacking ordered(LPSO)structure composed of Mg-NiY can be successfully formed,and the magnesium matrix composite reinforced by hybrid h-BN and LPSO structure is obtained.After ultrasonic treatment(UT),the thermal conductivity(TC)of the magnesium composite containing 3%h-BN reaches 99.92 W/(m·℃),and the average coefficient of thermal expansion(CTE)of the composite from room temperature(RT)to 100℃is 18.36×10^-6K^-1.The tensile strength and elongation of the composites reach 171 MPa and 3.9%,respectively.The magnesium alloy material with both high mechanical properties and excellent thermal properties was obtained.