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

AbstractIn situ Al–Cr/Al composites were prepared by ultrasonic vibration aided casting method in this paper, and the effects of ultrasonic time on microstructure, mechanical properties and damping capacities of Al–Cr/Al composite were systematically investigated by X-ray diffraction, SEM, electronic universal testing machine and the torsion pendulum internal friction tester. The results show that the ultrasonic vibration significantly refines the Al–Cr intermetallic compound reinforcement. The Al–Cr hybrid intermetallic compound reinforcements are found in the matrix, the size of in situ hybrid reinforcement has minimum value and the tensile strength of Al–Cr/Al composite has maximum value with the increase in the ultrasonic time. When the ultrasonic power and treatment time are 1 kW and 10 min, the tensile strength and elongation reach 188 MPa and 8·4% respectively, 61·48 and 52·72% greater than those of composites without ultrasonic assistance respectively. With high energy ultrasonic vibration, Q−1 re...