The Research On Continuous Casting Of Single-crystal Metals Apparatus Under Conditions Of Vacuum Melting And Argon Shield And Preparation Of Single-crystal Copper

The technique of continuous casting of single-crystal metals(CCSC),which integrates advanced directional solidification with high efficiency continuous casting,is a new near-net-shape processing technique.In the course of continuous casting of single-crystal metals,the purification of metals is an important factor which can affect the properties of ingots.At the same time,accurate control of the process parameters is a key of continuous casting of single-crystal metals.In this paper,we designed and manufactured a set of horizontal CCSC apparatus under the conditions of vacuum melting and argon shield according to the fundamental principles of continuous casting of single-crystal,in order to improve the purification of metals and accuracy of control for process parameters. Single-crystal copper wires 6mm in diameter have been produced by this apparatus, we have analyzed the results of purification and properties of the single-crystal copper wires.A horizontal CCSC apparatus under the conditions of vacuum melting and argon shield is self-designed and made,which is fitted with smelter of vacuum melting and the control by PLC for process parameters.The vacuum melting is transformed steadily to the argon shield and it ensures the experiment of CCSC.Single-crystal copper wires 6mm in diameter have been produced successfully by this CCSC apparatus. The process parameters are:the temperature of liquid copper is 1135°C;the mould temperature is 1108°C;casting speed is 20mm/min;the cooling distance is 25mm;the rate of flow of cooling is 621/h.The hydrogen concentration and oxygen concentration of single-crystal copper which produced by this apparatus are lower 66.67% and 71.43% than the raw copper,achieve lppm and 2ppm;the total concentration of impurity of the single-crystal copper wires is lower by 89.77% than the raw copper,and is lower by 85.84% than the single-crystal copper wires which produced by the former continuous casting of single-crystal apparatus.The elongation and reduction of cross-section of single-crystal copper ingots produced by this apparatus are higher 85.85% and 34.79% than polycrystal copper;The tensile strength and the yield strength of single-crystal copper are lower 15.52% and 31.42% than polycrystal copper;The electrical resistance decreases 10.5%.It is true that the single-crystal copper which produced by the apparatus in this papaer can become the excellent cold working ingots and conductive materials.