Effect of Annealing Process on the Microstructures and Mechanical Properties of AZ31B/A356 Composite Plate Fabricated by Cast Rolling

摘要

The effect of annealing process on the microstructures and mechanical properties of Mg/Al composite plates fabricated by cast-rolling was investigated in this study. The results show that the interfacial transition zone can be divided into three regions: a Mg transition region, an Al transition region, and an intermediate region, respectively. The microhardness of the interfacial transition zone is higher than that of AZ31B and A356.When the annealing temperature is 250 oC, the thermodynamic and kinetic conditions required for the formation of new intermetallic compounds have been met. While, for an annealing temperature at, or above, 300 oC, the width of the interfacial transition zone, annealing temperature, and time follow model: ? X 2 = 2 . 07 × 10 4 exp ? 60407 RT t ? 11 . 54 exp 21211 RT . The shear strength reaches a maximum value of 116 MPa when the annealing temperature is 200 oC. Cleavage fracture occurs at the side of the AZ31B alloy and quasi-cleavage fracture at the side of the A356 alloy.