Carbide Formation Process in Directionally Solidified MAR-M247 LC Superalloy

作     者：Chen, Jian Huang, Baiyun Lee, J.H. Choe, S.J. Lee, Y.T. 

作者机构：Cent S Univ Technol Powder Met Res Inst Changsha 410083 Peoples R China Changwon Natl Univ Dept Met & Mat Sci Changwon 641773 South Korea Korea Inst Machinery & Mat Changwon 641010 South Korea 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：1999年第15卷第1期

页      面：48-52页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

主　　题：Nickel alloys 

摘      要：Carbide nucleation, growth and trapping behavior in directionally solidified MAR-M247 LC alloy and the corresponding mechanism have been investigated. Carbide forming element enrichment controls the carbide nucleation and the carbide growth behavior. If the carbide forming element enrichment and the nucleation sites are suitable, carbide nucleation can occur both above and below the liquids temperature. Heterogeneous carbide nucleation is the preferred nucleation mechanism at low carbide forming element enrichment. Carbide growth occurs mainly at inter- secondary gamma dendrite arm area and lower part of the mushy zone. The carbides are subsequently trapped at these positions after growing to a certain size. Some carbides are only partially trapped by the solid-liquid interface and the carbide growth accelerates after being partially trapped. A critical growth rate exists between 2 multiplied by 10** minus **6 m/s and 5 multiplied by 10** minus **6 m/s. The carbide volume fraction decreases in the directionally solidified part at slow growth rate which is caused by the lack of suitable growth site and the low trapping ability of the solid-liquid interface. (Edited author abstract) 16 Refs.