Study On Microstructure And Properties Of High-melting Point High-conductivity Copper Alloy

"Strengthening metallurgy" is an important means for the flash smelting furnace and blast furnace to achieve energy saving and environmental protection. With the constantly increasing strength of smelting, the lining of the protection technology become more and more important. Domestic and foreign common solution to the high thermal conductivity of the copper cooling water jacket is buried in the brickwork. However, pure copper cooling water jacket has two shortcomings inevitable. On one hand, due to the low melting point of pure copper and higher temperature in the furnaces during the process, although a slight fluctuation occurred in the water yield, water pressure or tempreture, the water jacket may rapidly melting, and be difficult to change; On the other hand, the thermal conductivity of pure copper is so high that easily result in a higher water temperature in tube wall, and even boiling, leading to the apperance of " air hammer", or forming the extremely dangerous "dry" part. Therefore, the development of copper alloy materials with high melting point and high conductivity in developing a better alloy cooling water jacket has the very vital significance.Based on the copper alloy phase diagram, the composition of copper alloys is designed by orthogonal array.Ball Mill was used to mix metal powder which had been preparation. The mixture powder is formed dense and thin pancake under certain pressure. In this paper, the copper alloys were fabricated by arc-melting and induction melting injection moulding. The copper alloys sample organization by prepared of different processes, the melting point and thermal conductivity were analyzed and tested. The relationship between alloy composition, preparation processes, the microstructure, alloy melting point and thermal conductivity was Studied.The main conclusions are as follows.(1) Under the experiment condition, the results show that the crystal grain of copper alloy prepared by vacuum non-consumable arc-melting is coarse. The crystal grain of copper alloy prepared by high-frequency induction melting and reaction-injection moulding is superfine.(2) For the same ingredients of copper alloy, the thermal conductivity is improved as for coarser grains.The grain is the smaller, alloy thermal conductivity rate is lower. (3) Under the experiment condition, Cu-Ni-based alloy has serious dendritic segregation; Cu-Cr-based alloy has Gravity Segregation; Cu-Fe-based alloy has cellular segregation.(4) Under the experiment condition, the primary and secondary order of melting point effect on copper alloy elements is Ni-Co-Fe. The effect of Ni on the copper alloy melting point is significantly. The content of Ni in copper alloys is bigger, the alloy melting point is higher. The Second factor is Co. The last factor is Fe.(5) Under the experiment condition, the primary and secondary order of thermal conductivity effect on copper alloy elements is Ni-Fe-Co. The content of Ni in copper alloys is bigger, the thermal conductivity is higher. The Second factor is Fe. The last factor is Co.(6) Under the experiment condition, the optimal solution of the high-melting point high-conductivity copper alloy is Cu-8Ni-4Fe-2Co by comprehensive balance analyzing of orthogonal experiment. The melting point can reach1121.9℃.The thermal conductivity can reach73.48(W/m·k).