The microstructure and mechanical properties of rheo squeeze casting Mg nd Zn alloy were studied
(1) The microstructure evolution of Mg nd Zn alloy melt during electromagnetic stirring (rotating magnetic field) was studied. The effects of different stirring parameters (stirring time, voltage and frequency) on the microstructure of alloy slurry were studied, including solid phase ratio, primary phase size and shape coefficient, so as to control the slurry microstructure and obtain the best technological parameters. In addition, based on the existing thermodynamic differential equations, the nucleation and growth mechanism of primary phase in electromagnetic stirring process was discussed.
(2) Effect of die temperature on Microstructure and mechanical properties of rheo squeeze casting Mg nd Zn alloy. The effects of die temperature on the phase composition, grain size, alloy density, dislocation density and mechanical properties of the alloy were studied. In addition, the microstructure evolution of the alloy formed by rheo squeeze casting during solid solution process was discussed, and the heat treatment process was optimized.
(3) Effect of pressure on Microstructure and mechanical properties of rheo squeeze casting Mg nd Zn alloy. The effects of pressure on phase composition, grain size, alloy density, dislocation density and mechanical properties of the alloy are discussed. In addition, based on the existing theories and data, the effects of pressure on the undercooling and nucleation rate of Mg nd Zn alloy melt were discussed
Influence law.
(4) The strengthening mechanism of Mg nd Zn alloy prepared by different forming processes was studied. The strengthening contribution of different strengthening factors to rheo squeeze casting, metal mold casting and conventional squeeze casting was compared and analyzed, and the strengthening mechanism of the alloy was elucidated.
(5) Effects of trace y on Microstructure and mechanical properties of Mg nd Zn alloy prepared by metal mold casting and rheo squeeze casting were investigated. The Mg nd Zn alloy with excellent properties was prepared by alloying with trace y element. The effects of different contents of Y element on the microstructure and mechanical properties of the alloy at room and high temperature were analyzed, and the reasons for strengthening the alloy by Y element were discussed.