铜铝爆炸复合材料界面及性能分析

发布时间：2018-05-20 09:09

本文选题：铜铝复合材料 + 微观结构　；参考：《江苏科技大学》2015年硕士论文

【摘要】：铜和铝都是良好的导体材料,在电力、电子、电器等领域具有非常广泛的应用。地壳中的铜含量占0.01%,随着铜资源的不断短缺,上世纪六、七十年代就提倡“以铝代铜”的方针,现在则是以铝节铜。铜铝双金属复合材料不仅仅具有铜材的导电导热性好的优点,同时具有铝材的质量轻、耐腐蚀、美观和经济等优点。铜铝复合材料加工方法很多,作为电力系统过渡联接金具,DL/T346标准规定,铜和铝的连接可以采用摩擦焊、闪光焊、钎焊、爆炸焊接等焊接方式或铜铝过渡复合片。铜铝复合是异种材料连接,由铜铝二元相图可知,铜和铝在固态下存在多种金属间化合物,如CuAl2、CuAl、Cu2Al、Cu3Al2等,在焊接过程中产生的金属间化合物,对接头力学性能和导电性能都有影响。本文从组织到成分到性能分析铜铝爆炸复合材料的优劣,并将其与不同复合工艺下铜铝复合材料做对比,从而为优化过渡线夹及金具构件的制造工艺及推广提供理论依据。由试验可知,铜铝爆炸复合材料的界面具有波状特征。界面两侧发生了一定距离的塑性变形并且界面处硬度最大,随着离界面距离的增大,硬度由大到小过渡到母材硬度。界面处存在明显的前漩涡和不明显的后漩涡,漩涡中的成分为CuAl和CuAl2,硬度值较大。界面处形成了厚度约为13μm的扩散层。波浪状界面比平直界面多了机械咬合作用,故力学性能上优于轧制、钎焊、扩散焊、闪光焊的平直界面。界面成分上,轧制界面的成分为铜铝固溶体,“轧制+退火”界面的成分为铜铝固溶体和金属间化合物43lCuA。钎焊界面为钎料层。闪光焊界面形成了金属间化合物Al4Cu9。扩散焊界面成分为铜铝的固溶体和金属间化合物94lCuA和43CuAl。爆炸复合界面化合物主要为CuAl和CuAl2。根据电阻率从小到大的顺序,CuAl2CuAl43CuAlAl4Cu9。故在界面成分上,爆炸复合界面对导电性损耗小于其他工艺。不同复合工艺下的阻抗大小排序如下:扩散焊试样钎焊试样闪光焊试样“轧制+退火”试样轧制试样爆炸焊试样。可以看出爆炸焊试样电阻率具有优势。发生腐蚀的可能性为轧制最大,大小顺序为轧制试样钎焊试样“轧制+退火”试样爆炸焊试样扩散焊试样闪光焊试样。腐蚀电流为扩散焊的最小,即扩散焊最耐腐蚀。其耐蚀性大小顺序为扩散焊试样闪光焊试样爆炸焊试样“轧制+退火”试样轧制试样钎焊试样。综上所述,铜铝爆炸复合试样和轧制、扩散焊、钎焊、闪光焊试样对比,在导电性、力学性能和耐腐蚀性上都具有一定的优势。能够为铜铝过渡金具及构件的节能、安全服役提供较好的技术保障。
[Abstract]:Copper and aluminum are good conductor materials. They are widely used in electric power, electronics, electrical appliances and so on. The copper content in the earth's crust accounts for 0.01%. With the continuous shortage of copper resources, the policy of "replacing copper with aluminum" was advocated in the 1960s and 1970s, and now it is copper with aluminum. Cu-Al bimetallic composites not only have the advantages of good conductivity and thermal conductivity of copper, but also have the advantages of light weight, corrosion resistance, beauty and economy. There are many processing methods for copper-aluminum composite materials. As a power system transition joint hardware DL / T346 standard, copper and aluminum can be connected by friction welding, flash welding, brazing, explosive welding and other welding methods or Cu-Al transition composite. Cu-Al composite is a kind of dissimilar material. It can be seen from the binary phase diagram of Cu-Al that there are many intermetallic compounds in solid state, such as CuAl2AlCuAlCu2AlCu2AlOCu3Al2. The intermetallic compounds produced during welding have an effect on the mechanical properties and conductive properties of the joints. This paper analyzes the merits and demerits of Cu-Al explosive composites from microstructure to composition to properties, and compares them with Cu-Al composites under different compounding processes, thus providing a theoretical basis for optimizing the manufacturing process and popularization of transition clamps and fittings. It can be seen from the test that the interface of Cu / Al explosive composites has wave-like characteristics. Plastic deformation occurred at some distance on both sides of the interface and the hardness at the interface was the largest. With the increase of the distance from the interface, the hardness changed from large to small to base metal hardness. There are obvious front vortex and unobvious posterior vortex at the interface. The components of the vortex are CuAl and CuAl2, and the hardness is higher. A diffusion layer with a thickness of about 13 渭 m was formed at the interface. The wave interface has more mechanical bite than the flat interface, so its mechanical properties are better than those of rolling, brazing, diffusion welding and flash welding. The composition of the interface is Cu-Al solid solution, the "rolling annealing" interface is Cu-Al solid solution and intermetallic compound 43lCuA. The brazing interface is a brazing layer. The intermetallic compound Al _ 4Cu _ 9 was formed at the flash welding interface. The diffusion bonding interface consists of solid solution and intermetallic compounds 94lCuA and 43CuAl. CuAl and CuAl2 are the main compounds at the explosive interface. According to the order of resistivity from small to large, CuAl2CuAl43CuAl4Cu9. Therefore, the electrical conductivity loss of explosive composite interface is smaller than that of other processes. The order of impedance in different composite processes is as follows: diffusion welding specimen brazing specimen flash welding specimen "rolling annealing" sample rolling specimen explosive welding specimen. It can be seen that the resistivity of explosive welding specimen has advantages. The probability of corrosion is the greatest for rolling, and the order of size is "rolling annealed" sample, diffusion sample, flash welding specimen, and the order of size is "rolling annealing" specimen. Corrosion current is the minimum of diffusion welding, that is, diffusion welding is the most corrosion resistant. The order of corrosion resistance is diffusion welding specimen flash welding specimen explosive welding specimen "rolling annealing" sample rolling sample brazing specimen. To sum up, compared with the samples of rolling, diffusion welding, brazing and flash welding, Cu-Al explosive composite specimens have some advantages in electrical conductivity, mechanical properties and corrosion resistance. It can provide better technical guarantee for energy saving and safe service of copper and aluminum transition hardware and components.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB331

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