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

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.