Papers by Author: Li Dong Wang

Abstract: Mg-1Zn-0.5Ca alloy was prepared by casting technology. The as-cast alloy was solution treated at 470°C for 24 h and aged at 175°C for 0-50 h. The microstructure, mechanical properties and electrochemical corrosion behavior of the alloys were investigated. The results showed that the average grain size of the as-cast alloy was 120-150 μm, and the precipitated phases were distributed uniformly in α-Mg grain. The as-cast alloy showed good mechanical properties. The tensile strength was 186 MPa, and ductility was 23%. A typical age softening responses was obtained during the aging treatment. In the electrochemical corrosion tests, corrosion of the alloys is improved in Hank’s solution and 3.5wt% NaCl solution after the solution and aged treatment. However, the aged treated alloys showed the better electrochemical corrosion resistance.

Abstract: The influences of hot forging and ageing treatment on the microstructure and mechanical properties of Mg−8Gd−2Y−1Nd−0.3Zn−0.6Zr (wt.%) alloy have been investigated. The results showed that the grains were significantly refined after hot forging. And the secondary phases in this alloy i.e. Mg₅(Gd_1-x-yNd_xY_y) and Mg₂₄(Y_1-x-yGd_xNd_y)₅ phases were fragmented to small particles due to the large strain during hot forging. Tensile tests revealed that mechanical properties were improved due to grain size refinement. Moreover, the as-forged alloy exhibited remarkable age-hardening response and mechanical properties were further improved by ageing treatment. The ultimate tensile strength, yield strength and elongation of the peak-aged (T5) alloy are 286 MPa, 245 MPa and 5.6 % at room temperature, and 211 MPa, 103 MPa and 19.4 % at 300°C, respectively.

Abstract: The lightest density of Mg has stimulated renewed interest in Mg based alloys for applications in the automotive, aerospace and communications industries. However, Mg in the pure form has relatively low strength, limited ductility and is susceptible to corrosion. Great efforts have been made to improve the mechanical properties of Mg alloys. Alloying Mg with other elements is one of the most important methods. An important class of Mg alloys is the Mg-Zn-RE system (RE = rare earth elements). In recent few decades, a series of new Mg-Zn-RE system alloys have been obtained, and detailed the structure and mechanical properties of the alloys. In this paper, the structure and mechanical properties of the Mg-Zn-RE alloys have been summarized. It showed that these alloys have high strength and they are prospected to be widely used in the future.