Effect Of The Heat Treatment On Microstructure And Properties Of Deformed Magnesium Alloy

Facing the pressure of environment protection and energy saving, magnesium alloy, with its low price and excellent performance, has become a hot research point in the field of materials industry.In this paper, AZ80 magnesium alloy was choose as test sample to study the deformation and heat treatment of it. Based on these, The relationship between microstructure and mechanical property of magnesium alloy is discussed. Meanwhile, the process design alloys are optimized to provide a basis for the formation of complex and high performance magnesium alloy.Firstly, the homogenization treatment could effectively improve the internal structure of the material, through the observation of the microstructure change, the evolution of the microstructure is studied. The effect of grain size uniformity and the second phase was researched, at the same time, the effect of homogenization treatment on the tensile strength and hardness of magnesium alloy was measured.Secondly, extrusion experiments were carried out at 10, 15, 20 ratio, under 300, 350, 380, 200, 410 centigrade, respectively, and the effects of the microstructure and properties were studied. After this treatment, the tensile strength of magnesium alloy was greatly increased, while the elongation rate was obviously higher, and the mechanical properties were improved significantly. Through the observation of the microstructure, it shows that with the rising of extrusion ratio, the plastic deformation could be effectively controlled; more intensive fine equiaxed grains of material could be made. Thus, by effectively refining the original organization of coarse grains, more stable fine grain structure could be obtained.Finally, the influence of heat treatment process on microstructure and properties of AZ80 alloy was studied. Appropriate parameter of heat treatment process was determined. Through the comparison analysis, the relationship between the hardness and the time of the material was studied. At high temperature, the 5min-60 min solution treatment was carried out to observe the grain size. Then the change of the surface hardness with the time under the extrusion ratio 20, treatment temperature 410℃ was studied. The change of grain diameter in the process of high temperature and solid solution with extrusion process parameters were discussed. The results show that the material which is processed by the homogenization, then extruded by 380℃ and ratio 10, and through 410 ℃ solid solution, the hardness is moderate and the toughness is good after 15 min treatment.