【作者】 郭剑；

【导师】 龙思远；

【作者基本信息】 重庆大学 ， 材料加工工程， 2007， 硕士

【摘要】 镁合金作为21世纪绿色金属结构材料,具有比重轻、高比强度、高比刚度,以及良好的电磁屏蔽能力、良好的铸造性能、易于再生利用以及优越的阻尼吸震降噪特性等一系列独特的优点,在汽车、摩托车、机械结构、手持工具、便携电器、机载设备、移动结构上的规模应用能减轻产品重量、减震降噪、降低能耗和排放、提高产品动力学性能,是一种极具应用前景的新型技术结构材料。镁合金约90%是通过铸造成型的,其中应用最为广泛的是高压铸造工艺。而工艺设计、模具设计和模具制造这三个环节都能够影响压铸的成败。因此,工艺设计、模具设计和模具制造的研究对压铸具有重要的实际指导意义。本论文针对我国镁合金压铸生产历史短,工艺设计和模具制造缺乏指导性技术文献的现状,根据镁合金熔铸工艺特性、压铸成形工艺本质、熔体充型流动和凝固特征与铸件表面和内部缺陷的形成理论,采用理论分析、数字模拟与实例铸件生产考证相结合的模式,系统研究了镁合金压铸成形过程液气两相充型流、充型速度场、温度场、熔体凝固过程固液分布、凝固时间与铸件缺陷形成的关系,提出了镁合金高品质、高效率、高工艺收得率的近终铸造成形工艺的浇注系统、溢流槽和排气槽的设计原理和模具制造质量控制要领,提出了镁合金精密压铸成形工艺和模具地优化设计规范雏形,提出了模具设计制造规范。并以手持工具构件的压铸生产为对象进行实践验证。实际生产应用结果表明,按照本文提出的工艺设计、模具设计及模具加工质量控制规范,能够达到提高压铸工艺设计的合理性、提高产品质量、节约模具成本、节约时间、提高产品开发效率的作用,实现保障压铸工艺设计技术水准、提升企业产品开发能力的目标。更多还原

【Abstract】 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.更多还原