| As one of the lightest metallic structural materials, magnesium and magnesium alloy have many advantages in practical application. Due to its damping capacity, good vibrational absorption, heat conductivity, electromagnetic shielding, easy to recycle and so on, it has attracted more and more attention from researchers all over the world, considered to be the ecological metallic structural materials of the 21st century. However, microstructure and composition inhomogeneity is inevitable in the as-cast magnesium ingots. The inhomogeneity of as-cast magnesium alloys goes as follows: 1. appearance of the non-equilibrium second phase and excessive excess-phase result in the formation of a dendritic network; 2. the solubility of alloy element in the base leads to supersaturation, forming the supersaturated solid solution; 3. the composition of solid solution in the Mg base distribute extensively, causing the dendritic or transgranular segregation. In order to eliminate the inhomogeneity existing in the Mg matrix, homogenizing treatment was used to improve the attributes of Mg alloys ingot.The microstructure of AM30 magnesium alloys obtained at different heat treatment parameters is researched and the results of metallographic experiment are also analyzed in detail. By researching the microhardness of all metallographic samples, the microhardness-time and microhardness-temperature curves are reached under varied processing conditions. The effects of annealing time and temperature on homogenization are discussed at length. The microhardness distribution variance is utilized to illustrate the homogenizing quality. Aided by the results of SEM and EDS, the distribution of main elements in AM30 magnesium alloys is discussed qualitatively. Meanwhile the phase changes between as-cast and homogenized samples can be got by ways of analyzing X-ray spectrum, which can be served as an effective tool determining the second-phase distribution and the quality of homogenization. According to the experimental results and practical production requirement, the optimal annealing parameter is obtained to be 430℃×8h.Hot compression experiment of AM30 magnesium alloys was carried out on Gleeble-1500 at different temperatures of 573k～673k and different strain rates of 0.001 s-1～0.1s-1. The flow stress-strain curve was obtained. The deformation activation energy and stress hardening exponent were calculated to be 134kJ/mol and 6.2, respectively. The relationship between flow stress and deformation temperature and strain rate is analyzed at length. The results show the flow stress strongly depends on the deformation temperature and strain rate. The flow stress increases with the increasing of strain rate and decreases with the increasing of temperature and the fit deformation temperature and strain rates are obtained to be 573k~623k and 0.001s-1~0.1s-1, respectively. High strain rate and low temperature will be better.In light of data acquired from thermal deformation test and matured technology parameter of AZ31, the extrusion experiment was carried on AM30 magnesium alloys. Following the solution and aging treatment on extrusion tubings of AM30 magnesium alloys, the relation between microhardness and solution and aging time is reached. and the strengthening effects is also studied according to the relation and results of extrusion test. The results show the microhardness didn't increase apparently and the way to obviously heighten the properties of AM30 using solution and aging treatment is not feasible.
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