中文摘要：

采用选晶法在改进型Bridgman定向凝固炉上制备镍基单晶高温合金DD403和DD407,研究不同合金缩松含量以及凝固参数对缩松的影响。结果表明,抽拉速率V=100μm/s时,DD403和DD407缩松含量分别为0.034vol%和0.014 vol%;随抽拉速率增加,DD403中缩松含量呈先减少后增加的趋势。

英文摘要：

Ni-based single crystal superalloy DD403 and DD407 were prepared with selecting-crystal method in the improved directional solidification furnace Bridgman. Different alloy porosity contents and the influence of solidification parameters on porosity were studied. The results indicate that the volume fractions of porosity in DD403 and DD407 are 0.034vo1% and 0.014vo1% at withdrawal rate V=100 μm/s. For single crystal superalloy DD403, the volume fraction of porosity decreases firstly and then increases with the increase of withdrawal rate.