Microstructures and mechanical properties of quasicrystal reinforced AZ31 matrix composites

In order to improve the mechanical properties of AZ31 alloys, the repeated plastic working process was employed to fabricate the AZ31-based composites reinforced with stable icosahedral quasicrystal particles. The microstructure of the composites has been investigated by XRD, SEM, TEM and HREM, and their mechanical properties have also been studied. The results showed that the RPW process reduced the grain size significantly, and the average grain size was only about 500 nm after 200 cycles of RPW. A good metallurgical bond interface between the quasicrystal particles and the Mg matrix was found in their crystallographic orientation relationship of ( 1   0   1 ¯   0 )Mg//2-f. The composites exhibited the maximum yield tensile strength of 334 MPa and the maximum ultimate tensile strength of 372 MPa at room temperature, respectively. The enhanced mechanical properties were attributed to the strengthening effect of quasicrystal particles and the refined microstructure.