7050铝合金平面凝固探索研究

发布时间：2018-05-14 18:35

本文选题：7050铝合金 + 平面凝固　；参考：《东北大学》2014年硕士论文

【摘要】：Al-Zn-Mg-Cu合金作为高强铝合金,在航空航天领域及地面运载工具方面应用广泛,是极为关键的一类轻质高强结构材料。高强、高韧、耐腐蚀的铝合金作为今后的主要发展方向具有重要的研究价值。近年来,随着航空航天事业的不断发展和国防现代化建设步伐的加快,我国对高性能的Al-Zn-Mg-Cu铝合金板材的需求也日益紧迫。目前,在全世界范围内铝合金铸锭的商业化生产大部分是使用传统的DC铸造技术,应用平面凝固技术铸造铝合金铸锭还比较少。本论文工作依托教育部优先发展领域项目《铝合金平面凝固技术研究》,以Al-Zn-Mg-Cu系超强合金中的7050铝合金为研究对象,对平面凝固铸造工艺进行探索性研究,设计并制造平面凝固铸造设备,并对使用不同铸造工艺时铸锭的质量进行检测分析,研究实现平面凝固的可行性方案,为平面凝固技术的进一步完善打下基础,以期建立具有知识产权的完善的铝合金平面凝固铸造技术,并最终实现这一技术的商业化应用。本论文主要得出以下结论： (1)考察研究了分流方式以及冷却板材质对熔体凝固前沿温度场的影响,其中采用边部分流、钢制冷却板铸造时温度场的分布均匀,可以较好地实现铝合金的平面凝固。 (2)铸锭中各位置Zn、Mg、Cu三种溶质元素的含量均在平均值附近呈微幅波动,无明显的宏观偏析存在,基本达到了平面凝固的溶质均匀化目标。 (3)铸锭的微观组织研究表明,其凝固组织中a-A1均为等轴晶或等轴枝晶,与DC铸造组织存在显著差别。 (4)轧制处理后合金抗拉强度为350MPa,延伸率为12.22%,硬度和电导率分别为117.50HV和40.50Ms/mm；经过时效处理后合金的抗拉强度达到545MPa,延伸率为13.33%、硬度和电导率分别为169.00HV和43.40Ms/mm。
[Abstract]:As a high-strength aluminum alloy, Al-Zn-Mg-Cu alloy is widely used in the field of aerospace and ground transport. It is a very important lightweight high strength structural material. High strength, high toughness and corrosion resistant aluminum alloy have important research value as the main development direction in the future. In recent years, with the continuous development of Aerospace industry and the development of aerospace industry, The pace of modernization of national defense is accelerating, and the demand for high performance Al-Zn-Mg-Cu aluminum alloy sheet is becoming increasingly urgent in our country. At present, the commercial production of aluminum alloy ingot in the world is mostly using the traditional DC casting technology, and the application of plane solidification technology to casting aluminum alloy ingot is still relatively small. This paper work relies on education. The research on aluminum alloy plane solidification technology in the Ministry of priority development field, 7050 aluminum alloy in Al-Zn-Mg-Cu superalloy is studied, the plane solidification casting process is researched, the plane solidification casting equipment is designed and manufactured, and the quality of the ingot in different casting processes is detected and analyzed. The feasibility of surface solidification has laid a foundation for the further improvement of the plane solidification technology, in order to establish a perfect aluminum alloy flat solidification casting technology with intellectual property, and finally realize the commercial application of this technology.
The main conclusions of this paper are as follows:
(1) the effect of the split flow mode and the material of the cooling plate on the temperature field of the melt solidification front is investigated and studied. The distribution of the temperature field is uniform when the steel cooling plate is cast, which can better realize the plane solidification of the aluminum alloy.
(2) the content of three kinds of solute elements of Zn, Mg, Cu in the ingot are slightly fluctuated near the average, and there is no obvious macro segregation, which basically achieves the homogenization target of the solute in the plane solidification.
(3) microstructure of the ingot shows that the a-A1 of the solidified structure is equiaxed or equiaxed dendrite, which is significantly different from that of DC casting.
(4) the tensile strength of the alloy after rolling is 350MPa, the elongation is 12.22%, the hardness and the conductivity are 117.50HV and 40.50Ms/mm, respectively, and the tensile strength of the alloy reaches 545MPa after aging treatment, the elongation is 13.33%, the hardness and the conductivity are 169.00HV and 43.40Ms/mm., respectively.

【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TG292

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