超声辅助铸造法制备原位合成Al-Cr/Al复合材料研究

Research on in-situ Al-Cr/Al composites fabricated by ultrasonic aided casting technology

利用超声振动辅助铸造法制备了Al-Cr/Al原位复合材料,应用XRD、SEM以及能谱分析(EDS)研究了复合材料的微观结构。通过M-2000型磨损试验机研究了Al-Cr/Al原位自生复合材料的耐磨性能。结果表明,超声振动对原位增强体细化明显,随着Cr含量的增加,原位增强体含量增加,增强体尺寸增大。不同类型的Al-Cr金属间化合物在基体中同时生成,形成混合增强相;随着Cr粉末粒径增大,原位增强体尺寸具有最小值。随着Cr含量和粒径的增大,复合材料的磨损率呈先降低后升高的趋势。Cr含量为8%,粒径为75μm时,复合材料的磨损率最小,为0.294%,耐磨性能最好,相对纯铝耐磨性提高约8.5倍,磨损机制主要为磨粒磨损。

In-situ Al-Cr/Al composite was prepared by the ultrasonic vibration aided casting method in this paper.Microstructure was characterized by XRD,SEM and EDS.The wear resistance of composites was investigated by M-2000wear tester.The results show that the ultrasonic vibration significantly refines the Al-Cr intermetallic compound reinforcement.With the increase of Cr,the content and size of Al-Cr intermetallic compound reinforcement increase.The Al-Cr hybrid intermetallic compound reinforcement exists in the matrix at the same time.With increase of the Cr powder particle size,the wear resistance of in-situ Al-Cr/Al composite and in situ reinforcement size both have minimum value.When the content of Cr was 8%,the particle size was 75μm,the fine Al-Cr intermetallic compound reinforcement distributes in the composites evenly;meanwhile,the wear rate was minimum,which was 0.294%.The wear resistance of composites was 8.5times that of pure aluminum. The wear mechanism was mainly abrasive wear.