TiN/Cr涂层锆合金包壳高温氧化与抗热冲击性能研究  

High temperature oxidation performance and thermal shock resistance of TiN/Cr-coated zirconium alloy cladding

作　　者：肖魏魏 刘义龙 黄景昊 李佳涛 刘世宏 杨晨 XIAO Weiwei;LIU Yilong;HUANG Jinghao;LI Jiatao;LIU Shihong;YANG Chen(School of Mechanical Engineering,University of South China,Hengyang 421001,China;Hunan Collabora‐tive Innovation Center for Nuclear Fuel Cycle Technology and Equipment,Nanhua University,Hengyang 421001,China)

机构地区：[1]南华大学机械工程学院,湖南衡阳421001 [2]南华大学核燃料循环技术与装备湖南省协同创新中心,湖南衡阳421001

出　　处：《粉末冶金工业》2024年第1期94-101,共8页Powder Metallurgy Industry

基　　金：湖南省自然科学基金资助项目(2020JJ5467);衡阳市科技计划资助项目(202150063435)。

摘　　要：为了研究TiN/Cr涂层锆合金的高温氧化性能和抗热冲击性能,采用磁控溅射制备了TiN/Cr涂层锆合金样品,分别开展高温氧化和抗热冲击性能试验,并对高温氧化和抗热冲击后的样品微观结构、物相及结合强度等进行表征。结果表明磁控溅射制备的TiN/Cr双层涂层之间存在明显界线,样品表面存在类圆形的团聚凸起,但涂层结构致密,无裂纹和孔隙等缺陷。高温氧化后,表面Cr涂层部分被氧化为Cr_(2)O_(3),呈不规则的多面体结构,中间TiN涂层中Ti原子向表面扩散,与O结合形成TiO_(2),呈长条状结构,且Cr_(2)O_(3)聚集区域呈鼓泡状。在涂层与基体界面处,向内扩散的Cr原子和向外扩散的Zr原子形成约5μm厚的Cr-Zr扩散层。同时,O原子持续向样品内部扩散,与基体中Zr原子结合形成ZrO_(2)。虽然TiN/Cr涂层锆合金的氧化增重小于无涂层锆合金,且样品保持相对完整,但是由于O原子的持续扩散,内部锆合金被氧化,说明TiN/Cr涂层无法为锆合金提供良好的长时抗高温氧化性。热冲击试验后,表面涂层依然完整包覆整个样品,但样品表面存在熔池状区域,并伴随微裂纹和孔隙,且涂层膜/基结合强度明显降低。In order to study the high temperature oxidation properties and thermal shock resistance of TiN/Cr-coat-ed zirconium alloys,TiN/Cr-coated zirconium alloy samples were prepared by magnetron sputtering.High tempera-ture oxidation and thermal shock resistance experiments were carried out respectively,and the microstructure,phase and adhesion strength of the samples after high temperature oxidation and thermal shock resistance were characterized.The results show that there is a clear boundary between the TiN/Cr double-layer coatings prepared by magnetron sputtering,and there are round-like agglomeration protrusions on the surface of the samples,but the coating structure is dense and free of defects such as cracks and pores.After high-temperature oxidation,the sur-face Cr coating is partially oxidized to Cr_(2)O_(3),which is an irregular polyhedral structure.Ti atoms from the TiN coating diffuse to the surface and combine with O to form TiO_(2),which is a long-striped structure.The Cr_(2)O_(3)aggrega-tion area is bubbling.At the interface between the coating and the substrate,the in-diffused Cr atoms and the outdiffused Zr atoms form a Cr-Zr diffusion layer with a thickness of about 5μm.At the same time,O atoms continue to diffuse into the sample and combine with Zr atoms to form ZrO_(2).Although the oxidation weight gain of the TiN/Cr coated zirconium alloy is smaller than that of the uncoated zirconium alloy,and the sample remains relative-ly intact,the internal zirconium alloy is oxidized due to the continuous diffusion of O atoms,indicating that the TiN/Cr coating cannot provide good long-term high temperature oxidation resistance for zirconium alloy.After the thermal shock test,the surface coating still completely covers the entire sample,but there is a molten pool-like area on the surface of the sample,accompanied by microcracks and pores,and the adhesion strength of the coating film/substrate is significantly reduced.

关 键 词：TiN/Cr涂层燃料包壳 磁控溅射 高温氧化性能 抗热冲击性能 扩散 

分 类 号：TG174.4[金属学及工艺—金属表面处理]