大气等离子喷涂制备低氧含量厚钨涂层  

High Thickness Tungsten Coating with Low Oxygen Content Prepared by Air Plasma Spray

作　　者：张小锋[1,2,3] 于磊[3] 杨震晓[2] 邓春明[2] 

机构地区：[1]华南理工大学材料科学与工程学院,广州510640 [2]广州有色金属研究院新材料研究所,广州510650 [3]北京科技大学核材料研究所,北京100083

出　　处：《材料工程》2014年第5期23-28,34,共7页Journal of Materials Engineering

基　　金：国家磁约束核聚变能研究专项(2010GB109000)

摘　　要：采用等离子球化技术对不规则钨粉进行球化,以还原后的球形钨粉为原料于CuCrZr合金基体上在氮气保护下,用大气等离子喷涂制备聚变堆用厚钨梯度涂层。利用X射线衍射(XRD)对钨粉和涂层进行物相分析,采用扫描电镜(SEM)对钨粉和涂层微观形貌进行观察,使用O/N测量仪、激光热导仪和拉伸试验机分别对涂层氧含量、热导率和结合强度进行测量,用X射线光电子能谱(XPS)对钨涂层中钨元素的价态进行分析。结果表明:在氮气保护下,采用大气等离子喷涂成功制备了以Cu-Mo/Mo-W为过渡的约2mm厚钨涂层,其结合强度为15.2MPa。相对真空热处理而言,H2还原热处理能显著降低等离子球化钨粉和钨涂层的氧含量,H2处理后涂层中氧含量从0.93%(质量分数,下同)降至0.17%。在钨涂层制备过程中由于存在对流氧化和扩散氧化,导致涂层存在微量的氧化物,其中氧化物主要以WO2.72和WO3存在。Irregular tungsten powders were spheroidized by air plasma spray （APS）. Using reduced spheroidized powders, graded tungsten coatings with Cu-Mo/Mo-W bond coating were prepared on CuCrZr alloy under the protection of nitrogen by air plasma spray. The phase and microstructure of tungsten powders and coatings were analyzed by XRD and SEM. The oxygen content, thermal conductivity and bonding strength of coatings were measured by O/N tester, laser thermal conductivity instrument and tensile testing machine respectively. The chemical valence state of tungsten in the coating was investigated by XPS. Results indicate that the tungsten coating with thickness of about 2mm can be prepared successfully, and its average bonding strength is 15.2MPa. Compared with vac- uum heat treatment, reduction of H2 can evidently decrease the oxygen content of spheroidized tung- sten powder and coating. After reduction of H2, the oxygen content of tungsten coating decreases from 0.93 ~ （mass fraction） to 0. 17%. During spray process, it consists of convection and diffusion oxida- tion. So the tungsten coating has trace amounts of oxide in it, which mainly contains WO2 72 and WO3.

关 键 词：钨粉 等离子球化 大气等离子喷涂 钨涂层 

分 类 号：TG174[金属学及工艺—金属表面处理]