Study on Processing Technology and Microstructure and Properties of High Strength Magnesium Alloy for Mechanical Parts

In order to solve the problem of poor plasticity of Mg-Gd-Y alloy, the microstructure and properties of Mg-Gd-Y alloys of solid solution state and forged at different temperatures were studied. The results showed that the grain size of solid solution Mg-Gd alloy was not uniform, and the average size was about 225 μm; when the forging temperatures were 440℃ and 410℃, the number of second phases in the alloys were large, and a large number of dispersed second phases could inhibit the formation of dynamic recrystallization; with the decreasing of forging temperature, the tensile strength and yield strength of Mg-Gd alloy showed increasing trend; when the forging temperature was 470℃, the elongation of Mg-Gd alloy reached the maximum value of 19.2%, and when the forging temperatur reduced to 440℃ and 410℃, the elongation decreased; the tensile fracture surface of the solid solution Mg-Gd alloy showed the feature of brittle fracture, and the tensile fracture surface at the temperature of500℃ was mixed fracture, while the fracture surfaces of the Mg-Gd alloys were characterized by ductile fracture at 470℃, 440℃ and 410℃.