Production process of copper clad aluminum bus bar with instantaneous bonding method
Copper clad aluminum bar is a new type of conductive material. The outer layer is copper, the inner core is aluminum, and the volume ratio of copper to aluminum is 15: 85 (weight ratio 37:63). This product is designed to replace the pure copper bar, and the cost of the copper bar can be reduced by half by obtaining the same current carrying capacity.
according to According to the "skin effect" principle, the current is concentrated on the surface of the conductor, while the current flowing through the inner core of the conductor is very small, so the copper in the inner core of the pure copper conductor plays a small role. According to this principle, the copper clad aluminum bar replaces the copper in the core of the copper bar with aluminum, and combines it into a copper clad aluminum composite conductive material through a series of complex processes.
This new material makes full use of the characteristics of copper, such as strong corrosion resistance, small surface contact resistance, and large current carrying capacity. It also has the advantages of light weight and low cost of aluminum bars. "Integrating science and technology into tradition and transforming harmony into inclusiveness", copper clad aluminum bars give full play to the advantages of copper and aluminum materials, and at the same time properly overcome their respective shortcomings, which is the development direction of conductive materials.
Copper aluminum composite busbar is commonly known as copper clad aluminum busbar in Chinese and copper clad aluminum busbar in English Co pp er-clad aluminum bus bars。 At present, the main standard to be implemented is the People's Republic of China power industry standard DL/T 247-2012 Copper Clad Aluminum Bus for Power Transmission and Transformation Equipment issued by the National Energy Administration on April 6, 2012 and implemented on July 1 of the same year.
Its significance is mainly to reduce the consumption of copper. China is a country rich in copper and aluminum, with copper resources 70% depends on imports, so the National 863 Plan strongly advocates manufacturers to develop new copper aluminum composite materials, so as to reduce China's consumption of copper and achieve the strategic goal of "saving copper with aluminum".
In addition, since copper is much more expensive than aluminum, another significant role of copper clad aluminum bars is to reduce material costs for enterprises. The price of copper clad aluminum bars with the same electrical performance is only that of traditional pure copper bars About 50%. On the premise of ensuring quality, it can produce good benefits for enterprises. Therefore, the emergence of copper clad aluminum bars is in line with the national strategic needs, the concept of social energy conservation and consumption reduction, and the demands of enterprises to reduce costs.
Copper aluminum composite row is a kind of aluminum based, outer layer coated with copper. According to its manufacturing process, it can be divided into : Cladding welding is a method of preparing copper clad aluminum wires at home and abroad. Some domestic enterprises use this process to make copper clad aluminum bars. This method is to use the flat and vertical rollers to press with the same core, coat the copper strip concentrically on the aluminum bar, then carry out argon arc welding on the longitudinal seam, and then go through stretching and annealing. The rolling and crimping method is used to crimp the cleaned copper strip from the top and bottom two wide sides Aluminum plate The copper strip and aluminum plate are pressed together with pressure exerted by the roller, and then are annealed after being straightened or further treated. Hydrostatic extrusion method, die casting and rolling direct forming method, die casting and rolling direct forming process developed by Huatong Company, copper and aluminum are solid-liquid combination, and good composite layer is formed through special process treatment. The composite layer is formed by the copper layer melted by aluminum and the mutual diffusion of copper and aluminum in a large area, which truly realizes the metallurgical bonding. This method is thicker than the solid bonding composite layer and has higher bonding strength. Insert the cleaned aluminum rod into the cleaned aluminum rod Copper tube The composite billet is made inside and put into the static liquid an extruder The metallurgical combination between copper and aluminum is realized by using high hydrostatic pressure and large deformation rate. Aluminum core and copper tube, remove the oxide film on the outside of the aluminum core and the inside of the copper tube, press the aluminum core into the copper tube, stretch or roll to make the solid phase bonding between the copper tube and the aluminum core, pull to the required dimensions, so that they form a bimetallic diffusion bonding between atoms, with a bright, round and defect free surface. It is a new type of conductor material that combines the high quality and stable conductivity of copper with the low cost energy of aluminum with low contact resistance. It can replace the pure copper bar as a whole, with copper accounting for 20% and aluminum accounting for 80%. It is 2.5 times longer than the pure copper bar under the same specification, and its current carrying capacity is 85% of the pure copper bar. Choosing a slightly larger specification can completely achieve the same current carrying capacity, and meet the technical requirements for wire diameter and mechanical and electrical performance required by customers
