The Effect Of Plastic Deformation Of Cast Magnesium Alloy AZ80 On Its Microstructure And Performance

In order to provide some basis theories about practical process of magnesium alloy production, the homogeneous-state cast AZ80 magnesium alloy was studied by means of extrusion trials ,to study the effect of plastic deformation of cast magnesium alloy AZ80 on its microstructures and performance,and even the differences in the process of forming.First of all, parts of the billets were homogeneous annealed to form the homogeneous-state specimens. After determined parameters of the extrusion process, the extrusion test of the homogeneous-state cast magnesium alloy AZ80 were carried out. By the testing methods of metallographic observation and tests of the mechanical performance at room temperature and so on, we researched the specimens that of extruded caste and homogeneous-state caste, so we can see the change orderliness of the microstructures and performance. As follows:Dynamic recrystallization had took place in all the extruded samples, there is a large number of small equiaxed grains in the parallel flow lines, and the grains were thinner than that before extruded obviously. From the experimental data, we can think of that the best range of temperature on recrystallization of the AZ80 magnesium alloy was about 390℃; with the rise of the extrusion temperature, the tensile strength of the extruded homogeneous-state simples was phased changes, and the elongation was reduced , the trend of tensile strength and the elongation are both reduced after the first rise; by comparison, in the same conditions, the tensile strength of the extruded homogeneous-state simples are higher than that of the cast extruded simples, and the elongation shows good regularity.In the Experiment, as-cast AZ80 magnesium alloy in the T = 390℃, extrusion extrusion ratioλ= 75, the room temperature performance is better, meanwhile the extrusion force required is relatively small; After homogenization processed AZ80 magnesium alloy in the T = 390℃, extrusion extrusion ratioλ= 60, the room temperature performance is better, the extrusion force required is relatively small.