摘要
激光熔池中金属的凝固过程由于极端偏离平衡，并伴随有复杂的热量、质量及动量传输过程而变得十分复杂．本文以ＣＯ－Ｃｒ－Ｃ三元合金的γ－Ｃｏ－Ｃｒ７－ｘＣｏｘＣ３伪二元截面共晶合金系为对象，系统考察了在激光重熔后凝固组织的形成，探索了其形态选择演绎规律．研究表明，该伪二元截面合金系在激光重熔条件下有一个向碳化物成分方向倾斜的γ－Ｃｏ与Ｃｒ７－ｘＣｏｘＣ３共生生长区．并可观察到在足够大的过冷度下发生的非晶转变论文最后运用最高界面温度假设和相应的界面响应函数讨论了该合金系在激光重熔时凝固组织形态选择图并与实验结果作了比较．
The solidification in a laser remelting pool is a very complex process which extremely deviated far from cquilibrium. with Co-Cr-C alloys a microstructure selection evolution process in a laser remelting pool was investigated. The results shows that a skeined coupled growth zone of γ-Co and Cr7-xCoxC3 csists in the Co-Cr-C alloy system. At high enough growth rates primary γ-Co dendritce appear in the microstructure of the eutectic alloy. A wide coupled growth zone was observed in the laser remelted traces for the alloys and an amorphous transition in laser remelting with high scanning speed was discovered. With a highest interface temperature assumption and a microstructure selection criterion the microstructure selection evolution process in the laser remelting pool was discussed. A good agreement of the theoretical results with the experimental measurements was shown.
出处
《上海大学学报（自然科学版）》
CAS
CSCD
1996年第2期205-211,共7页
Journal of Shanghai University:Natural Science Edition
基金
国家自然科学基金
