Effect Of Sintering Aids On Sintering Property Of Quartz Based Coating For Lost Foam Casting

Lost foam casting coating is the key technology of LFC casting. Quartz based LFC coating due to its low price and easy to get have been widely used. But the quartz based LFC coating have the poor performance in sintering. In this paper we used sintering aids to improve the Sintering Property. In order to make coating have the property of high refractoriness and low sintering temperature.In this paper we study the effect of mica powder, talc, potassium feldspar powder, calcium powder on sintering property through the single factor gradient method. Different content sintering aids were prepared by coating and made into standard samples. The samples were sintered at six different temperature. After sintered the simple was taken test of bending strength, in order to analysis the influence of the sintering aids to bending strength. Mature the apparent porosity, bulk density of the simples to analysis the relationship between sintering degree and sintering aids and temperature. The SEM analysis was taken to make out the influence of aids to the internal microstructure. Do the XED analysis of sintered samples, through the analysis of internal coating after sintering and combined with the phase diagram analysis the effect of sintering agent on sintering properties.Finally obtained the following conclusions:The sintering aids increased the bending strength, at the test additive amount the bending strength of the sample respectively increased from to3.2MPa～5.8MPa to4.3MPa～10.6MPa、8.4MPa～14.6MPa、9.3MPa～14.3MPa、7.3MPa～14.2MPa.The sintering aids decreased the apparent porosity of the sample, the figure decreased from59.6724%～65.2638%to27.1186%～57.2864%、27.1186%～57.2864%、41.3249%～54.9674%、44.5.87%～63.1579%。The aid of sintering aids make the microstructure of the sample more densification. With the increase of the aids there are more liquid phase and more integrity.The sintering aids decreased the melting point of the sample make it more easily to chemical reaction. More aids make the component more complex.So we can say that the aid of the sintering aids improved the sintering property of the coating. Although the different aids have the different effect, but they all make coating have the property of the high refractoriness and low sintering temperature.