Magnesium Alloy Precision Die-casting And Mould Design & Manufacture

As an environment-friendly metallic structure material for 21rt century, Magnesium alloys possess low density, high specific strength and stiffness, good electromagnetic shielding capability, outstanding cast-forming capability, easy of recycling and excellent capability of vibration absorption and reduction of noise. They find more and more applications in automobile, motorcycle, machinery, hand-holding tools, portable electric appliances industries, where the weight-saving and damping performance becomes a necessity for product performance. Most importantly, more than 90% of Mg alloys used for manufacturing structures are formed with different foundry processes, among which, die-casting is playing a most important role. To ensure a successful die-casting practice, the design of die-casting process, mould design and quality insurance of die-quality are most concerned.Based on the fact that Mg die-casting practice just started a few years ago, there is no technical documents that is capable of guide the design and quality control of die-casting practice, the focus of the present dissertation study is to product a guide line for processing optimization, mould design and quality control via theoretical analyses, numerical simulation and production examination in accordance with the die-casting properties of Mg alloys, mass and heat transportation during die-filling, temperature distribution and solidification, and their relationships with the formation of the associated processing defects. Based on the above studies, guidelines for the optimal design of mould processing structures such as gating system and over-flow were proposed, and the routines of quality insurance during mould manufacturing were suggested and examined with the mass production of Mg hand-tooling castings.The results indicate that, under the guidance of the proposed guidelines, the processing and mould design come out more optimal, and the die quality was ensured during the process of die manufacturing. The purpose of implementation of die-cast numerical optimization and mould design & manufacture quality insurance can be more easily reached. With the help of the guidelines, the theory of Mg die casting can be used to back-up the formation of producing capability of market products.