Copper Cladding Aluminum Bus Duct Repared By Casting And Rolling Process

Now copper and copper alloy materials are not only the strategic materials that ourcountry pays great attention to, but also the fundamental materials for the industrialdevelopment. However, our country is short of copper material, supply of copper indomestic relies heavily on import. Aluminum is an important conductive material whoseconductivity lands just behind silver, copper and gold. Besides, there are a great number ofaluminum resources to satisfy domestic demands or export to international markets. Cu/Alcompound material has the advantage of both Cu and Al, such as high transmitting rate ofelectricity and heat, low resistance of electricity and beauty on the outside of Cu, as well aslight weight and economy of Al. It could be used in many areas as resource, electricity, bus,machines, and metallurgy equipments.Nowadays, Cu/Al bus ducts roll cladding has the disadvantages as the big rollingreduction ratio and low bonding strength. Besides, Cu/Al bus ducts roll cladding is cracked.Aiming at those problems, in this experiment copper clad aluminum bars are rolled andcomposited after preparation of copper clad aluminum rods by casting. The effect to thecopper cladding aluminum bus ducts rolling is studied by the process parameter of copperunder different surface treatment methods, pressure ratio and intermediate annealingtemperature. And the best rolling technology is determined: intermediate annealingtemperature is400℃; rolling passes are four times, and the first time of reduction rate isabout44%, and the second time of reduction rate is about35%, and the third time ofreduction rate is about31%, the fourth time of reduction ratio is about26%. The thicknessof4mm of copper cladding aluminum bus duct is achieved under the condition of theprocess Through the analysis of the roll casting technologies of copper cladding aluminumbus duct, the interior of the copper tube had been treated by chemical nickel plating, andthe reasonable intermediate annealing temperature and reduction, the cracking of the twolateral surface of the copper cladding aluminum bus duct was effectively solved.Through the analysis of the diffusion layer of the copper aluminum cladding interface,bonding strength, tensile properties and electrical conductivity of the copper claddingaluminum bus duct which underwent annealing heat treatment, the optimal annealing heat treatment process is determined. The optimal annealing heat treatment process: thetemperature of annealing is300℃while the time is60minutes. The thickness of thediffusion layer of the copper aluminum composite interface is4.42μm, the conductivity is57.5Ms/m, the tensile strength is161.33MPa, the elongation is17.4percentages, andbinding strength is greater than29.4KN with optimal annealing heat treatment process.