【摘要】 以Al-B2O3为反应体系,采用熔体直接反应法与超声处理相结合制备了原位Al2O3/ADC12复合材料。采用光学显微镜观察基体和复合材料的显微组织,用X射线衍射(XRD)、扫描电子显微镜(SEM)及能谱仪(EDS)分析增强相的分布、形貌以及成分。结果表明:在超声作用下,原位反应能够有效快速地进行,增强颗粒与基体的润湿性得到了显著改善;超声和增强颗粒的协同作用使得复合材料的显微组织和力学性能有了较大的改善;复合材料显微组织中的晶粒得到细化,分布更加均匀,硅相形貌由原来的块状、长针状、条状逐渐转变为短棒状、颗粒状;在一定范围内,随着超声功率的增加,复合材料的组织和性能更理想;经600 W超声辅助合成的复合材料的综合力学性能较好,此时抗拉强度达到224.5 MPa,硬度HV达到112.7,分别比基体ADC12提高了25.7%、27.1%。更多还原

【Abstract】 In this paper,in-situ Al2O3/ADC12 aluminum matrix composites have been successfully synthesized by combining melt direct reaction method with ultrasonic treatment in the system Al-B2O3.The microstructures of the matrix and composites were observed by optical microscope.The distribution,morphology and composition of the reinforced phase were analyzed by XRD,SEM and EDS.The results show that the in-situ reaction can proceed effectively and fleetly,and the wettability between reinforced particles and the matrix can be also improved significantly via the ultrasonic treatment.The grains of the microstructure refine in the composites and distribute much uniformly in the composites.The morphology of Si phase is changed into rod-like shape,particle-like shape from original bulk-like shape,long acicular-like shape,strip-like shape gradually.Besides,within an appropriate range,the microstructures and properties of the composites are getting better and better with the increasing of ultrasonic power.In addition,the mechanical property of the composite is better when ultrasonic power is 600 W.The tensile strength and hardness reach 224.5 MPa,HV112.7,which is increased by 25.7%,27.1%than those of the matrix,respectively.更多还原