冷轧及退火对铜铝复合板界面层与性能影响研究

发布时间：2018-05-06 01:00

  本文选题：铜铝复合板 + 铸轧复合　； 参考：《河南科技大学》2015年硕士论文

【摘要】：铜铝复合板是一种双金属复合材料,不仅具备铜的热传导率高,接触电阻低等优点,还兼具铝的密度小,价格低廉等特点。目前,在军工、航空航天等高科技领域及散热基板、电器、建筑等普通民用领域均可见到铜铝复合板材的身影。本文研究的铜铝复合板材通过连铸连轧法制备,利用维氏硬度检测仪、剥离试验机、金属导电率检测仪、拉伸试验机等设备对复合板力学性能和导电性能进行了测试,利用SEM、EDS、XRD、TEM等微观分析仪器研究了结合层的微观形貌、成分及组织结构,分析了微观组织与宏观性能的关联性。重点研究了界面层形貌、板材力学性能、板材电导率随复合板冷轧压下率变化的规律以及退火工艺对冷轧处理后复合板界面层组织形貌,性能的影响规律,结果如下:1.采用铸轧复合法可以制备出结合效果和导电性能良好的铜铝复合板材,界面层由共晶组织α-Al+Cu Al2以及Cu Al2组成。铸轧法制备的铜铝复合板材,其结合强度高于其它复合法制备的复合板,复合板抗拉强度与延伸率均介于同尺寸纯铜、纯铝板材之间,趋肤效应的存在使复合板导电温升曲线和纯铜板相近。2.压下率较高时,冷轧会使铸轧复合板材界面层发生断裂和破碎进而影响复合材料性能;冷轧压下率从29%逐渐增加到57%时,界面层的破碎程度逐渐加重,剥离强度先迅速减弱后缓慢增强,复合板抗拉强度逐渐增大,延伸率则随之下降,电导率逐渐降低。3.不同退火工艺处理后的冷轧复合板,其界面层微观组织,力学性能均产生明显的变化,退火处理使得破碎的界面层重新变得连续致密;在300℃-400℃的热处理条件下,冶金层中存在Cu Al2、Cu9Al4和Cu Al三种铜铝化合物,随着温度升高或退火时间延长,各相的厚度均逐渐增长,板材基体硬度先迅速减小然后保持稳定,板材电导率则逐渐回升,剥离强度先逐渐增大,在300℃×3h时达到最大值,继续提高退火温度或者延长退火时间,剥离强度开始逐渐下降。
[Abstract]:Cu-Al composite plate is a kind of bimetallic composite material, which not only has the advantages of high thermal conductivity and low contact resistance of copper, but also has the characteristics of low density and low price of aluminum. At present, in the military industry, aerospace and other high-tech areas and heat dissipation substrate, electrical appliances, buildings and other common civil fields can be seen in copper and aluminum composite sheet figure. The copper-aluminum composite plate studied in this paper was prepared by continuous casting and rolling method. The mechanical and electrical properties of the composite plate were tested by Vickers hardness tester, stripping tester, metal conductivity tester, tensile tester and so on. The microstructure, composition and microstructure of the bonding layer were studied by means of SEM EDS- XRD- TEM, and the relationship between microstructure and macroscopic properties was analyzed. The morphology of interface layer, the mechanical properties of composite plate, the variation of sheet electrical conductivity with cold rolling reduction rate and the influence of annealing process on the microstructure and properties of interfacial layer of composite plate after cold rolling were studied. The results are as follows: 1. Cu-Al composite sheet with good bonding effect and electrical conductivity can be prepared by casting and rolling recombination method. The interface layer is composed of eutectic structure 伪 -Al Cu Al2 and Cu Al2. The bonding strength of Cu-Al composite plate prepared by casting rolling method is higher than that of other composite plates. The tensile strength and elongation of the composite plate are between pure copper and aluminum sheet of the same size. Because of the skin effect, the conductive temperature rise curve of composite plate is close to that of pure copper plate. When the reduction rate is high, the interfacial layer of cast-rolling composite sheet will be broken and broken, and then the properties of composite material will be affected by cold rolling, and when the reduction rate of cold rolling is increased from 29% to 57%, the breaking degree of interface layer will gradually increase. The peeling strength decreased rapidly and then increased slowly, the tensile strength of the composite plate increased gradually, the elongation decreased and the electrical conductivity decreased gradually. The microstructure and mechanical properties of the interfacial layer of the cold-rolled composite plate treated by different annealing processes are obviously changed. Annealing treatment makes the broken interfacial layer become continuous and compact again, and under the heat treatment conditions of 300 鈩，

本文编号：1850053