Mg-Si系镁合金强度与阻尼性能的平衡优化

发布时间：2019-03-03 12:57

【摘要】：随着现代化科技日趋完善,出行的便捷性和安全成为了人们首先考虑的因素。航空航天与飞行器也开始沿着轻量化、高速化和高效率化的方向发展。但也会给人们的生活带来一些麻烦,即噪音与振动的问题。因此,对于结构的轻量化、节约能源、减低振动降低噪音的性能提出了急切的需求。镁不仅拥有密度低、比强度高的一些良好的商用性,而且它也是阻尼性能非常好的金属材料,因而能够满足上述需求。针对以上的所提出的问题,本文首先选用Mg-1Si合金作为研究的母合金,在其基础上添加一些变质元素的中间合金,熔炼使其成为合金体系。采用OM金相显微组织分析、X射线衍射(XRD)、扫描电子显微镜(SEM)、拉伸力学性能测试、动态机械分析(DMA)等实验手段研究了体系中的组织形貌、力学性能及其阻尼性能的变化。本文首先介绍了镁合金的阻尼性能的研究意义,概括了镁合金阻尼性能的国内外的研究现状,总结了目前金属阻尼材料的表征、测量方法及形成机理,提出了本论文的研究目的及意义。研究通过拟添加Mn、Zr、Ca这三种不同的变质元素的中间合金来改善Mg-1Si的力学性能,并研究这三种元素对Mg-1Si合金的组织及阻尼性能的影响。结果表明,这三种元素都能明显的使得母合金的组织得到细化,组织细化后抗拉强度和伸长率也得到了提高。然后测试其阻尼性能的变化,发现三种元素都能够使得母合金的阻尼性能得到提高,成为高阻尼的合金,这三种变质元素对合金阻尼性能的影响机制都可以用G-L理论来解释。
[Abstract]:With the development of modern technology, the convenience and safety of travel has become the first consideration. Aerospace and aircraft also began to develop along the direction of lightweight, high-speed and efficiency. But it will also bring some trouble to people's life, namely noise and vibration. Therefore, there is an urgent demand for the lightweight structure, saving energy, reducing vibration and reducing noise. Magnesium is not only a good commercial material with low density and high specific strength, but also a metal material with very good damping property, so it can meet the above requirements. In order to solve the above problems, Mg-1Si alloy was selected as the parent alloy, and some master alloys with modified elements were added to the alloy, and melting made it into an alloy system. The microstructure and morphology of the system were studied by means of OM metallographic microstructure analysis, X-ray diffraction (XRD), scanning electron microscope (SEM),) tensile mechanical properties test and dynamic mechanical analysis (DMA). Changes in mechanical properties and damping properties. In this paper, the research significance of damping properties of magnesium alloys is introduced, the research status of damping properties of magnesium alloys at home and abroad is summarized, and the characterization, measurement methods and formation mechanism of metal damping materials are summarized. The purpose and significance of this paper are put forward. The mechanical properties of Mg-1Si were improved by adding Mn,Zr,Ca master alloy, and the effects of these three elements on the microstructure and damping properties of Mg-1Si alloy were studied. The results show that these three elements can obviously refine the microstructure of the parent alloy, and improve the tensile strength and elongation after the refinement. Then the change of damping property is tested and it is found that all three elements can improve the damping property of parent alloy and become a high damping alloy. The mechanism of the influence of these three modification elements on the damping properties of the alloy can be explained by the theory of G\ -\ {\} L\-1.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG146.22

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