| The copper chromium alloy is one of the main materials of the large size contact,whichis of high strength,hardness,good electric conduction and heat conduction.In the view of the traditional powder metallurgy method,molten infiltration method and vacuum arc melting method preparing Cu-Cr has defects of high production cost,complex process and low yield of the product.The thermit reduction secondary refining method preparing process was proposed by research group for Cu-Cr alloy preparation,which process is simple,cost is low,and key process was system investigated.On the basis of previous studies,this paper mainly focuses on the performance of four slag system of refining slag and aluminum thermic reduction of Cu Cr alloy chemical composition control,as well as the aluminum heat reduction-secondary refining of Cu Cr alloy macro and micro structure.Firstly this article examined the performance of different refining slag from the slag viscosity,density,surface tension.The results shown that with the increase of SiO2,the viscosity of slag sample as CaO-Al2O3-CaF2-SiO2 decreased gradually,the sticky transformation temperature was higher,the density and surface tension decreased firstly and then increased;with the increase of MgO,the viscosity of the slag system of CaO-Al2O3-CaF2-MgO was gradually decreased,and the density of the slag was first decreased and then increased,which was smallest when MgO was 4%;the viscosity and sticky transformation temperature of the slag was lower when the content of MgO was 4%,CaF2 was 20%,CaO:Al2O3=1:2,which was beneficial for the separation of slag and gold..Next,the effect of different slag system on the Cu Cr alloy prepared by Al thermal method is compared,the results showed that the removal of inclusion and porosity of CaO-Al2O3-CaF2-MgO four slag system is better.The calorific value of the quality of the different units of the chromium content in the alloy effect was examined,the results showed that CuCr25 unit reaction heat effect was 3300kJ/kg and CuCr50 unit reaction heat effect was 3500kJ/kg,chromium content was more higher in the alloy.By improving the material of chromium oxide with quantity,can effectively improve the aluminothermic reduction chromium content alloy prepared by melt,CuCr25 alloy chromium oxide with intake for 150%intermediate ingot chromium content up to 29.72%,CuCr50 alloy chromium oxide with intake for 150%middle chromium content of ingot can reach 46.42%.Finally,the effect of process parameters on the microstructure and porosity of Cu-Cr’alloy was investigated,The results showed that effect of induction furnace slag refining grain-refinement,inclusion and porosity removal was obviously,through the preparation of slag refining,CuCr25,CuCr40 products with the industry standard could be prepared. |
