Thermal-type Single-crystal Copper Rod Continuous Casting Apparatus And Processes

In recent years,numerous studies show that:single crystal copper wires with outstandingmechanical properties and conductivity have been attracted more and more attention by widelyused in the fields of electronic communication,network,audio and video device,national defenseand other fields,with a very broad application prospects.In this paper,a horizontal continuous directional solidification apparatus was preliminarilydesigned and manufactured on the basic principle of Ohno Continuous Castingtechnology(OCC),the influence of furnace structure with different inlets and outlets wasresearch by the numerical simulation.At the same time,the continuous casting model wasestablished,the influence of the continuous casting process parameters on solidification processof solid-liquid and surface quality was analysis by combining numerical simulation andexperiment,the reasonable process reference was obtained under the experimental conditions，and the evolution law of microstructure of single crystal was discussed.The main results and conclusions are as follows:(1) A set of horizontal OCC apparatus is self-designed and manufactured,which holds thecharacteristics of simple structure,reliable operation and meets the necessity.(2) The furnace body of OCC apparatus is analyzed by numerical simulation,the resultsshow that:it has a greater impact for casting solidification process stability by the inlet andoutlet structure,and the optimizing scheme6is proposed.(3) In the process of OCC,the position of solid-liquid interface is mainly affected by moldtemperature,casting speed,cooling distance.and were moved to casting export with theimprovement of mold temperature and casting speed or the reduce of cooling capacity.(4) The simulation and experimental results show that:in the experimental device,theprocess parameter selection range to obtain single crystal copper rods with smooth surfacequality is: the liquid level height is6-10mm,melt temperature is1373-1423K,mold temperatureis1363-1373K,casting speed is80-100mm/min,cooling distance is40-50mm,cooling water is800-900ml/min.(5) Based on the simulation results and field tests,the single crystal copper rods8mm indiameter with smooth surface quality have been successfully produced,and three growth stagesof equiaxed crystal,columnar crystal and single crystal have been verified,the mechanicalproperties and conductivity can meet the requirements of single crystal copper rods.