梯度化铸型导热系数的实验研究

Experimental Determination of the Thermal Conductivity Coefficients of Gradient Mold

在树脂砂中加入石墨粉和锆砂,利用导热系数仪测量砂型导热系数,研究了锆砂和石墨粉的含量对铸型导热系数的影响,进行了实验验证,与Maxwell模型模拟计算的导热系数进行对比研究。结果表明,在石墨粉含量为8%、锆砂含量为30%时,砂型导热系数达到最大值,与树脂砂型相比导热系数提高了90%;混合砂型的晶粒比树脂砂型的细4μm。混合砂型浇注得到的铸件的抗拉强度比树脂砂型的抗拉强度高3%～4%,伸长率下降了0.8%～0.9%。

Graphite powder and zirconium sand were added into resin sand, and thermal conductivity coefficients of sand mold was measured by thermal conductivity meter. The influence of the content of zirconium sand and graphite powder on the thermal conductivity of the mold was studied. Experimental verification was carried out and the thermal conductivity calculated by Maxwell model was compared. The results show that the thermal conductivity of the sand mold reached the maximum when graphite powder content is 8% and zirconium sand content is 30%, which is 90% higher than that of the resin sand mold. The grain size of mixed sand mold is 4 microns finer than that of resin sand mold. The tensile strength of the castings obtained by pouring the mixed sand mold is 3% ~4% higher than that of the resin sand mold, and the elongation decreased by 0.8%~0.9%.