Research On The Directional Solidification Of Casting With Silicon Core

The quality of ceramic cores is the critical factor affecting the quality stability of casting hollow blades.The ceramic core is difficult to manufature,and the process is long.Operators,equipment,raw materials,technology and testing methods all pose great influence to the stability of the core quality.According to the present situation of domestic raw materials,through in-depth basic study,used to improve cores performance and the stability of quality.According to the structural characteristics of cores and different using conditions,hope to achieve the balance in two ways on high-performance and low cost.Finally established the system of ceramic cores,and to produce large-scale,stable,batch,high-quality core,improve the quality of the blade.Through the impact test of silica-based ceramic cores additive,quartz glass additives,the uniformity of cores' s paste mixing,and sintering process parameters to Core performance;through the impact test of less than 2 microns fine powder content to Core performance;through the impact test of the cristobalite's amount change to Core performance;determined the main influencing factors of various performance of silica ceramic cores,and the influence regularity and control technology,Made the matching principle of Ceramic core powder particle size,given the control range of the amount of silica ceramic cores additives,Found out the main factors and control process of Affect the sintering of silica core.establish the control process of cores' s paste mixing,analyzesed the main factors and control indicators of silica ceramic cores' s fashioned,the main influence factors and influence law of cristobalite crystallization is determined,Obtained the better formula of core components(19%F320+35%F220+30%mineralizer+12%F600+4%additive).the better performance index of core components formula are as follows:liquidity 260°,sintering shrinkage 0.35%,1550°C strength 35.17 MPa,1550°C single fulcrum deflection 0mm,the thermal expansion of 1550°C 0.6%.The characteristics of this formula of core is has excellent performance at high temperature.As far as possible to prevented shift core,Leakage core,and broken core.Reduced the firing shrinkage,prevented the sintering deformation of core.The biggest characteristics of fluidity of cores' s paste is good,a substantial increase than Regular fluidity 180° of this cores at fluidity,solved the problem ar the deformation and the crack about core forming technology.Pouring validation test showed that the core with the better formula can meet the needs of the production for the directional blade casting.