Preparation Of TiC/SiC Composite Powder By High Temperature Electrochemical Reduction Of High Titanium Slag

Titanium carbide,an important high temperature structural material,has the characteristics of high melting point,high hardness,low density and good chemical stability.When SiC is added to TiC,it can greatly advance the fracture toughness of titanium carbide and is widely used in machinery,aviation,microelectronics and high-tech fields,etc.At present,titanium carbide is generally prepared by carbothermal reduction method.However,there are many problems such as high reaction temperature,difficulty in removing impurities and uneven product composition in the process of material preparation.The preparation of TiC/SiC composite material is also long process,the reaction temperature is high,limiting its large-scale application.In this paper,TiC/SiC composite powders were prepared by direct solid deoxidation of high titanium slag using high temperature molten salt electrolysis?Fray-Farthing-Chen Process?.The method has the characteristics of short process and high product purity,which can overcome the shortcomings of traditional preparation technology and improve product quality,and has wide application prospect.In this paper,the high silicon content of high titanium slag as the raw material,through the thermodynamic theory analysis,constant cell voltage electrolysis,the study of electrolyte composition,electrolysis time,cell voltage,temperature,molar ratio of Ti to C,CaO content in molten salt for the influence rule of high titanium slag of direct electrolysis procedure.The main results are as follows:?1?In the CaO content is lmol%of CaCl₂-NaCl system,by controling cell voltage is 3.2V,the temperature is 900?,the molar ratio is Ti:C = 1:2,the electrolysis time is 6h,the high titanium slag can completely deoxidized to obtain TiC/SiC composite powder.The concentration of CaO in molten salt has an important effect on the electrolysis process.When the CaO content is 1?2mol%in molten salt,the reduction rate of high titanium slag can be improved effectively.On the contrary,with the increase in CaO content,will inhibit the reduction of CaTiO3.?2?In the CaCl₂ molten salt,by controling cell voltage is 3.1V,the electrolysis temperature is 850?,the electrolysis time is 3h,the high titanium slag can be completely deoxidized to obtain TiC powder.Study of CaO concentration in molten salt found that the electrolysis effect didn't advance significantly due to the addition of CaO.Therefore,by direct electrolysis reduction of high titanium slag in the CaCl₂ molten salt can obtain TiC/SiC composite powder.