Ni基合金粉中添加纳米CeO2粉体对激光熔覆层组织及高温腐蚀性能的影响  

Effect of Nanoscale Cerium Dioxide on Microstructure and High-Temperature Corrosion Behavior of Laser Cladding Nickel-Based Alloy Coating

作　　者：钱书琨 蒋冬青 汪新衡[2] 朱航生 

机构地区：[1]湖南科技经贸职业学院,湖南衡阳421001 [2]湖南工学院先进制造技术研究所,湖南衡阳421002 [3]衡阳丰顺车桥有限公司产品部,湖南衡阳421001

出　　处：《材料保护》2014年第5期27-29,42,共4页Materials Protection

基　　金：湖南省自然科学基金委员会与衡阳市人民政府自然科学联合基金（13JJ9025）;湖南省教育厅科研项目（12C1082）;衡阳市科技计划项目（2012KJ32）资助

摘　　要：为了揭示添加纳米粉体对激光熔覆层高温防护性能的影响，将纳米CeO2粉体加入NiCoCrAlY合金粉末中，采用压片预置式激光熔覆工艺在GH4037合金表面激光熔覆制备了纳米CeO2颗粒增强Ni基合金涂层，并对熔覆层进行了显微组织观测，研究了1000℃温熔盐热腐蚀性能。结果表明：添加适量纳米CeO2粉体的Ni基合金激光熔覆层出现大量细小等轴晶，组织明显细化、致密；添加纳米CeO2后熔覆层在高温熔盐中腐蚀后未出现明显的隆起和剥落现象，腐蚀层的深度明显减小，对Cr2O3膜的碱性溶解有一定的抑制作用，其抗高温热腐蚀性能显著提高。Nanometer CeO2 was added in NiCoCrAlY alloy powder. Resultant mixed powder was pressed into plates via pre-placing mode and then prepared into CeO2-reinforced Ni-based alloy coating on GH4037 alloy by laser cladding. The microstructure of as-prepared Ni-based alloy coating was analyzed by scanning electron microscopy,and its corrosion behavior of molten salt at 1 000 ℃was tested. Results indicated that laser cladding Ni-based alloy coating prepared in the presence of a proper amount of CeO2 powder contained a large number of fine equiaxed crystals,and its microstructure was obviously refined and dense. Besides,Ni-based alloy coating obtained in the presence of CeO2 powder underwent slight corrosion-induced protrusion and spalling,and its corrosion depth was small. Moreover,the title Ni-based alloy coating exhibited a certain degree of inhibition action against dissolution of Cr2O3 film in alkaline solution,and its anticorrosion ability against high-temperature molten salt was significantly improved.

关 键 词：激光熔覆 NiCoCrAlY合金粉末 纳米CeO2粉体 显微组织 高温热腐蚀性能 GH4037合金 

分 类 号：TG665[金属学及工艺—金属切削加工及机床]