Brief analysis of industry development of extrusion duralumin copper bar

There are many researches on heat-resistant aluminum alloy and medium strength aluminum alloy conductor materials at home and abroad. In contrast, there are few researches on high conductivity al alloy and its wires. The study of aluminum alloy casting with high strength and high conductivity was carried out in wuhan university of technology. By adding boron and rare earth elements at the same time, kunming university of science and technology achieved the goal of improving the mechanical properties of electrical round aluminum rod, reducing the resistivity and improving the performance of electrical round aluminum rod. Dalian university of technology has studied the composition optimization of electrical aluminum, and it is concluded that the composition optimization of industrial pure aluminum for electrical engineering can be summarized as "adding boron, limiting Si and relaxing Fe content". The research results show that the composition of flux has an important influence on the purification effect of electrical aluminum alloy. It should be designed reasonably so as to improve the mechanical properties and electrical conductivity of electrical aluminum rod. In 2010, wuxi huaneng cable co., ltd. applied for the invention patent of "a kind of high-conductivity duralumin wire and its manufacturing method", and disclosed a high-conductivity duralumin wire and its manufacturing method. Applied for the southeast university in 2013, a high conductivity of rare earth hard aluminum wire and preparation, invention patent, open the high conductivity of rare earth hard aluminum wire components, but also exposes the preparation methods of high conductivity of rare earth hard aluminum wire, mainly equipped with aluminum ingots, smelting, and then to boride, refined processing, such as electrical conductivity was 63% IACS, tensile strength of 160 mpa hard aluminum wires.

The production of electrical round aluminum rod is using continuous casting and rolling technology, the production process is mainly aluminum alloy melting, aluminum liquid purification, ingot casting and rolling. For aluminum solution with silicon content less than 0.08%, appropriate iron-silicon ratio can obtain qualified electrical aluminum products. Adding appropriate amount of al-b alloy and rare earth intermediate alloy into aluminum solution with high ferrosilicon content can meet the requirements of mechanical properties and electrical properties of products. Wei liangjie et al. purified the aluminum solution by means of secondary refining and controlled the composition of the alloy. Continuous casting is a process in which three technological parameters, namely casting temperature, casting speed and cooling speed, are reasonably matched, and appropriate rolling temperature and speed are also required in the process of continuous rolling. In the actual production process, according to different types of electrical aluminum, the rolling temperature is generally set at 480 ~ 520℃, and the final rolling temperature is 300 ~ 360℃. However, the preparation process of high conductivity hard aluminum alloy materials and related wires is complex and the production and use cost is high, so the existing preparation process cannot meet the preparation requirements of high conductivity hard aluminum alloy, and few manufacturers have the production capacity.

In order to increase the practical application of high conductivity aluminum alloy conductor materials, it is necessary to study the composition system of high conductivity aluminum alloy and its preparation process more deeply and systematically. Therefore, the development of high conductivity of hard aluminum alloy on the one hand, should be adjusted aluminum alloy components, control of sensitive element and trace alloy elements added more excellent methods so as to obtain the high conductivity of hard aluminum alloy composition is working on, on the other hand, should from the optimized the preparation technology of hard alloy, simplify the production process, reduce the production cost of ideas.

According to the above development ideas, the electrical conductor material project group of state grid smart grid research institute initially explored the composition of al-b-zr-re system hard aluminum alloy.

Through conventional melting process after melting cast into Φ 45 mm hard aluminum alloy ingot; Alloy ingot in 400 ℃ heat preservation made by squeezing Φ after 1 h of the 9.5 mm round rod; Dural round rod on a wire drawing machine through 15 times of cold drawing, the final preparation into a hard aluminum monofilament Φ 3.05 mm.

It can be seen from the test results of the prepared duralumin monofilament performance that, with the increase of Zr content, the conductivity of the duralumin monofilament decreases, the tensile strength increases, and the elongation has no obvious change trend. The comprehensive performance of the high-conductivity duralumin monofilament is significantly improved.