Due to its unique properties, the recognition of magnesium alloys in the industry continues to increase, and the scope of application is also expanding. At present, the main forming process of magnesium alloy is die-casting. In actual production, due to the needs of working conditions or process factors, it is often necessary to perform partial or overall plastic machining of magnesium alloy die castings. At the same time, the plastic machining of die castings can eliminate the shrinkage and porosity caused by the die casting process. , Improve the comprehensive mechanical properties of the material. However, magnesium alloys have poor plasticity and are difficult to perform plastic machining at room temperature; die-cast magnesium alloys are particularly difficult to perform plastic machining at room temperature due to the presence of a large number of near-network low-melting phases on the grain boundaries, and generally require thermoplastic machining. This limits the popularization and application of magnesium alloys to a certain extent.
In recent years, there have been many studies on the deformation behavior of magnesium alloys such as AZ31, AZ61, and AZ91 (non-die-cast state), but there are few reports on the deformation behavior of die-cast AZ91D magnesium alloy, especially the hot deformation behavior. In response to the above problems, this paper uses the Geeble-1500D thermal simulator to conduct a hot compression deformation experiment on the die-cast AZ91D magnesium alloy under the conditions of a strain rate of 0.01~10s -1 and a deformation temperature of 50~450℃ to study its Thermal compression deformation behavior; at the same time, the deformation microstructure was studied.
The main research work and results of the thesis are as follows:
