Effects Of Heat-treatment Technology On The Microstructures And Properties Of Semisolid Thixo-forming AZ91D Magnesium Alloy

Magnesium alloys are praised as green materials of 21th century . Because of magnesium alloys have many excellent properties, such as low density, good dimension stability and mechanical processing properties, low manufacturing cost high specific strength and stiffness, high heat and electrical conductivity, shock absorption, excellent electromagnetic shielding capability , as well as a good recovery capability. They are very important for the reduction of automobile weight , energy saving ,environmental protection and biological environment. In recent years, the application of magnesium alloys has become the important research item for the countries with the developing automobile industry.Semisolid microstructures are produced by strain induced melt activation (SIMA) and magnesium alloy castings are produced by thixoforming , as a producing method of the semisolid which exhibits an excellent prospect in the producing process of magnesium components.On the one hand ,the forming of semisolid structures is processing in solid state, which avoids burning and oxidation of magnesium alloy .On the other hand ,the precise controlling is easily processing to the stain inducing and isothermal heat-treatment of magnesium alloy in solid state ,which can obtain symmetrical semisolid global structures. Semisolid thixo-die casting is most widely used in thixoforming. It is a new die-casting technology which is based on liquid state metal die-casting. It gets over the shortcoming of traditional liquid state metal die-casting and can obtain die-casting which is very compact and can be strengthened by heat-treatment. Semisolid...