等通道角挤压制备7075铝合金组织及性能研究.docx

《等通道角挤压制备7075铝合金组织及性能研究》摘要：研究了不同时效制度对7075铝合金挤压型材组织和性能的影响，通过力学性能检验、微观组织分析、剥落腐蚀的检验对三种时效制度进行对比，旨在为提高7075铝合金综合性能提供参考关键词：7075铝合金；时效制度；力学性能；剥落腐蚀；金相组织通过对7075铝合金进行不同工艺的固溶处理，分析了固溶处理对7075铝合金显微组织和力学性能的影响结果表明：利用优化的固溶工艺处理后，可有效减少粗大的第二相尺寸和数量，提高合金元素的固溶过饱和度；采用490℃2h+130℃16h工艺处理后，可以明显提高铝合金的力学性能这类产品的形状特殊、壁厚薄，单位重量轻、公差要求非常严格，通常把这类产品称之为铝合金精密（或超精密）型材（管材），把生产这类产品的技术称之为精密（或超精密）挤压[1]铝合金特殊精密（或超精密）挤压材的主要特点是：（1）品种多、批量小、多为专用挤压材，其用途几乎遍及到各行各业和人民生活的各个方面，包括所有的挤压产品，如管材、棒材、型材和线材，涉及到各种合金和状态因其断面小、壁厚薄、重量轻、批量小，一般不易组织生产2）形状复杂、外形轮廓特殊，多为异形的、扁宽的、带翅的、带齿的、多孔的型材或管材。

单位体积的表面积较大，生产技术难度大3）用途广、性能和功能要求特殊为了满足产品的使用要求，选择的合金状态多，几乎涵盖沉淀强化7000系列铝合金是所有商用铝合金中强度最高的，广泛应用于军用、民用飞机以及体育用品的结构应用7000铝合金是由高密度的Guinier-Preston(G-P)区强化的，因为该区域的强原子键可以增加对位错运动的阻力1,2对于Al-Zn-Mg-Cu7075体系，经过溶液处理后，在低温(如室温)下时效，可以得到高密度的G-P区冷加工通常能提高金属和合金的强度，但对提高7000系列铝合金的强度效果不明显目前国内外所生产的扁锭、圆锭和空心锭,几乎都采用半连续铸造,即IX:法这种铸造方法的装置是由铝熔体分配流槽、流盘、浮标漏斗、结晶器和移动式升降铸造机等部件组成,用以铸造铸锭由于对铸锭质量提出了严格的新要求,故对传统的直接水冷半连续铸造方法和结晶器进行了相应的改造,开发了绝热模铸造、热顶铸造、横向铸造和电磁铸造并得到了推广应用,具有节能、提高生产率和质量的效果还相继开发和推广了板带、棒、线的连续铸挤和连续铸轧等新工艺关键字：7075铝合金；性能研究；国内外研究概况；Microstructure and properties of 7075 aluminum alloy prepared by equal channel Angle extrusion Absrtact：The effects of different aging systems on the microstructure and properties of 7075 aluminum alloy extruded profiles were studied, and the three aging systems were compared by mechanical property test, microstructure analysis and peeling corrosion test, so as to provide references for improving the comprehensive properties of 7075 aluminum alloy. Keywords: 7075 aluminum alloy; Limitation system; Mechanical properties; Exfoliation corrosion; Metallographic structure. The effect of solid solution treatment on microstructure and mechanical properties of 7075 aluminum alloy was analyzed. The results show that the size and quantity of coarse second phase can be reduced and the solid solution supersaturation of alloying elements can be improved by using the optimized solid solution technology. The 490 ℃ by 2 h + 130 ℃ after x 16 h, can significantly improve the mechanical properties of aluminum alloy. This kind of product has special shape, thick and thin wall, light weight per unit and strict tolerance requirements. Generally, this kind of product is called aluminum alloy precision (or ultra-precision) profile (pipe), and the production technology of this kind of product is called precision (or ultra-precision) extrusion [1]. The main characteristics of aluminum alloy special precision (or ultra precision) extrusion material are :(1) variety, small batch, mostly for special extrusion material, its use almost all walks of life and all aspects of peoples lives, including all extrusion products, such as pipes, bars, profiles and wire, involving a variety of alloys and states. Because its section is small, wall is thick thin, weight is light, batch is small, organize production not easily commonly. (2) complex shape, special contour, mostly shaped, flat wide, with wings, with teeth, porous profile or pipe. The surface area of unit volume is large and the production technology is difficult. (3) wide use, special performance and function requirements. In order to meet the requirements of the use of products, the choice of alloy state more, almost covered. Precipitation-strengthened 7000 series aluminum alloy has the highest strength among all commercial aluminum alloys and is widely used in the structural applications of military, civil aircraft and sporting goods. The 7000 alloy is reinforced by a high-density guinier-preston (g-p) region, where strong atomic bonds increase resistance to dislocation motion. 1,2 for al-zn-mg-cu7075 system, after solution treatment, aging at low temperature (such as room temperature), high-density g-p region can be obtained. Cold working usually improves the strength of metals and alloys, but not of 7000 series aluminum alloys. At present, the flat ingot, round ingot and hollow ingot produced at home and abroad almost adopt the semi-continuous casting, namely IX: method. The casting device is composed of aluminum melt distributing groove, flow plate, buoy funnel, crystallizer and mobile lifting casting machine for casting ingots. Due to the strict new requirements for the ingot quality, the traditional direct water-cooled semi-continuous casting method and the mold have been modified correspondingly, and the adiabatic mold casting, hot top casting, transverse casting and electromagnetic casting have been developed and applied widely. The new technology of continuous casting and extrusion and continuous casting and rolling of strip, bar and line has been developed and popularized successively.Keywords: 7075 aluminum alloy; Performance studies; Research situation at home and abroad;目录1绪论 42铝及铝合金特殊精密挤压材的特点 53铝合金特殊精密挤压材的分类 74国内外铝合金熔铸技术的现状 94.1熔炼技术 94.2铝熔体搅拌 94.3熔体处理技术 104.4铸造技术 114.5测试技术 124.6结束语 145实验内容 145.1试验方法 145.2结果与讨论 155.3结论 216 7075铝合金组织及性能的提高 216.1 7075铝合金性能提升。