高温涂层包覆贵金属热电偶的性能研究  

Study on properties of precious metal thermocouples coated with high temperature-resisting wear

作　　者：李凤 唐会毅 肖雨辰 吴保安 杨开舟 郑雅文 孙玲 郑磊 LI Feng;TANG Hui-yi;XIAO Yu-chen;WU Bao-an;YANG Kai-zhou;ZHENG Ya-wen;SUN Lin;ZHENG Lei(Chongqing Materials Research Institute Co.Ltd.,National Instrument Functional Materials Engineering Technology Research Centers,Chongqing 400707;Chongqing Hangli Industrial Co.Ltd.,Chongqing 401346)

机构地区：[1]重庆材料研究院有限公司国家仪表功能材料工程技术研究中心,重庆400707 [2]重庆航利实业有限责任公司,重庆401346

出　　处：《贵金属》2022年第4期14-18,共5页Precious Metals

基　　金：国家自然科学基金(U20A20232)。

摘　　要：通过等离子喷涂方法,使高温涂层均匀包覆在贵金属热电偶(Pt-10Rh/Pt)的裸丝上,其涂层厚度为30~50μm,并对样品进行稳定性试验。采用金相显微镜及扫描电镜对样品稳定性试验前后的涂层形貌、厚度、均匀性进行观察,结果表明:高温包覆涂层在贵金属裸丝上致密、均匀的分布,其长期稳定性比裸丝更好。样品在经过1400℃/200 h保温后,裸丝晶粒粗大,而高温涂层包覆的丝材晶粒比裸丝晶粒细小,高温涂层对贵金属丝材起到了一定的保护作用,增加贵金属偶丝的使用寿命,降低使用成本。The plasma spraying method was chosen in our study to make the high temperature-resisting coating on the bare wire of precious metal thermocouple(Pt-10Rh/Pt),and the coating thickness was 30~50μm.Then the stability test of the sample was conducted.Metallographic microscope and scanning electron microscope were used to observe the coating morphology,thickness and uniformity before and after the stability test.The results showed that the coating was densely and uniformly distributed on the precious metal bare wires,and the stability was improved.The grain size of the wires with the coating was much smaller than that of the bare wires after the test at 1400℃for 200 h.Therefore,the high temperature-resisting coating can protect precious metal base wires,increase their service life and reduce the cost.

关 键 词：等离子喷涂 高温涂层 贵金属热电偶 稳定性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]