Segregation of niobium in laser cladding Inconel 718 superalloy  

激光熔覆Inconel 718合金铌偏聚（英文）

作　　者：龙怡彤 聂璞林[1] 李铸国[1] 黄坚[1] 李想[1] 徐昕媚 

机构地区：[1]上海交通大学上海市激光制造与材料改性重点实验室,上海200240

出　　处：《Transactions of Nonferrous Metals Society of China》2016年第2期431-436,共6页中国有色金属学报（英文版）

基　　金：Project(51341004)supported by the National Natural Science Foundation of China;Project(S050ITP7005)supported by the Shanghai Jiao Tong University Undergraduate Innovative Practice Program,China

摘　　要：Inconel 718 superalloy is widely used in the aerospace and turbine industry. Segregation of niobium appears in the laser cladding Inconel 718 superalloy and consequently influences the phase transformation during the rapid solidification. In order to control the microstructure and improve the mechanical properties of the deposited coating, the the influence of solidification conditions on the segregation of niobium and the resultant formation of Nb-rich Laves phase was studied using the microstructure observation and EDS analysis. The results show that the cooling rate has considerable influence on the microstructure of the deposited coating. High cooling rate is beneficial for suppressing the segregation of Nb and reducing the formation of Laves phase, which is believed to be detrimental to the performance of the Inconel 718 alloy.Inconel 718高温合金被广泛地应用于航空航天和汽轮机领域。在激光熔覆Inconel 718合金中存在铌的偏聚现象,而铌偏聚会影响到合金在快速凝固过程中的相变。为了控制熔覆层的显微组织并提高其力学性能,采用组织观察和能谱分析研究凝固条件对铌偏聚及富铌Laves相形成的影响规律。结果表明冷却速度对熔覆组织具有显著影响。高的冷却速度有利于抑制铌的偏聚,减少对Inconel 718合金力学性能有害的Laves相的析出。

关 键 词：Inconel 718 superalloy segregation of niobium laser cladding cooling rate 

分 类 号：TG174.4[金属学及工艺—金属表面处理]