Microstructure and mechanical property of Al3Ti/Al-Mg-Mn composite in-situ synthesized at low temperature under vibration coupling fields

Al3Ti/Al-Mg-Mn composites were successfully prepared by in-situ reaction method under ultrasonic and mechanical vibration fields. The effects of reaction temperature and coupling time on microstructure evolution and mechanical properties at room temperature were studied. The results show that the coupling ultrasonic and mechanical vibration fields can promote the in-situ reaction, dispersal and refinement of Al3Ti particles. Compared with Al-Mg-Mn matrix, the room temperature tensile strength, yield strength and elongation of Al3Ti/Al-Mg-Mn composite treated under coupling fields at 760 celcius for 10 min are 222, 119 MPa and 8.1%, respectively. The tensile strength and yield strength values increase by 17.5% and 25.2%, and the elongation value decreases from 8.7% to 8.1%. The improvement of mechanical properties is mainly attributed to grain refinement strengthening, load transfer strengthening and thermal mismatch strengthening caused by Al3Ti reinforced phase, among which the thermal mismatch strengthening plays a great role in the improvement of the strength of composites.