【摘要】 本文利用光学及扫描电子显微技术、Ｘ射线择优取向分析等手段，对Ｍｏ杂质作用下的Ｎｉ－ＮｂＣ合金的形貌、取向等特点进行了研究．结果表明：在自由凝固下，领先形核与生长的ＮｂＣ初生晶依杂质含量不同，呈六面体和八面体两种形态．它们分别以＜１１１＞和＜１００＞晶向为择优生长方向．共晶团生长过程中，ＮｂＣ相的分支机制主要表现为择优生长方向的分支，而缺陷的作用是次要的．更多还原

【Abstract】 This paper studied the Ni-NbC alloy morphology and orientation character under the effect of impurity Mo, by using optical and scanning electron microscope(SEM)and X-ray preferred orientation analysis. Result has shown that the growing primary crystals have two kinds of morphologies: hexahedron and octahedron, while their preferred growth orientation is <111> and <100> , respectively. During the growth of eutectic alloy, NbC phase branched mainly on the preferred growth direction, while the effect of defect was minor.更多还原