W,Re过渡层对碳基体表面Al_(2)O_(3)涂层高温热匹配性和层间扩散的影响  

Alleviating High Temperature Thermal Mismatch and Element Diffusion of Al2O3 Coating on Carbon Substrate by Introducing W/Re Interlayer

作　　者：李东鹏 王卫泽[1] 黄继波 朱含 付鑫[2] 孙杰[2] Li Dongpeng;Wang Weize;Huang Jibo;Zhu Han;Fu Xin;Sun Jie(Key Laboratory of Ministry of Education of Pressure System and Safety,East China University of Science and Technology,Shanghai 200237,China;Shanghai Institute of Satellite Engineering,Shanghai 201109,China)

机构地区：[1]华东理工大学机械与动力工程学院承压系统与安全教育部重点实验室,上海200237 [2]上海卫星工程研究所,上海201109

出　　处：《稀有金属》2022年第9期1181-1189,共9页Chinese Journal of Rare Metals

基　　金：上海航天科技创新基金项目(SAST2019-056)资助。

摘　　要：在含碳材料表面沉积氧化铝(Al_(2)O_(3))涂层是目前常用的一种高温防护手段,但其在高温下长期使用,易产生涂层开裂、层间元素扩散等现象,进而导致防护失效。本文以大气等离子喷涂(APS)结合射频磁控溅射(RFMS)沉积铼(Re)涂层和钨(W)涂层作为过渡层,研究过渡层对碳基体表面沉积Al_(2)O_(3)涂层的高温下的热匹配性和层间扩散的影响。通过比较不同试样加热后的界面形貌发现,1100℃保温3 h后无W层的涂层试样表面开裂剥落,而添加过渡层的试样表面完好,截面微观结构分析也未发现明显开裂。对界面两侧元素扩散分析发现,添加过渡层W后Al元素扩散现象减弱,添加Re/W层后,元素扩散进一步降低。可见W层、Re/W层加入到含碳材料和氧化铝层间后,可提高涂层抗开裂剥落能力,且涂层层间元素扩散明显减弱。Alumina(Al_(2)O_(3))coating deposited on carbon-containing materials was a common high temperature protection method.However,when it was used at high temperature for a long time,it was easy to develop coating cracking caused by mismatch of thermal expansion coefficient and interlayer element diffusion caused by concentration difference,which leaded to protection failure.The re-fractory metal tungsten(W)had good stability at high temperature,and the thermal expansion coefficient was between the substrate and the alumina coating,which could improve the thermal matching of the coating.The low diffusivity of W could be used as the diffu-sion barrier between layers,and rhenium(Re)could reduce the formation of tungsten carbide(WC)in W layer and improve the pro-tective temperature of the coating.In this paper,Re and W were deposited by atmospheric plasma spraying(APS)combined with ra-dio frequency magnetron sputtering(RFMS)as transition layers to study the effect of transition layer on the thermal matching and interlayer diffusion of Al_(2)O_(3)coating deposited on the carbon substrate at high temperature.The tungsten coating was prepared by spherical tungsten powder with a purity of 99%and an average particle size of less than 45μm.The magnetron sputtering target with a purity of more than 99.9%was used for the deposition of Re and W films.The substrate of the sample was graphite with a carbon content of more than 99.5%.In order to study the thermal matching and diffusion resistance of the transition layer,three different coating samples were prepared in the experiment(Sample 1:Al_(2)O_(3)-C,Sample 2:Al_(2)O_(3)-W-C,Sample 3:Al_(2)O_(3)-W-Re/W-C).Before the coating was deposit-ed,the substrate surface should be coarsened by sand blasting and cleaned by anhydrous ethanol.The thickness of Re/W layer deposit-ed by magnetron sputtering was 2~3μm,the thickness of W layer deposited by plasma spraying was 80~100μm,and the thickness of Al_(2)O_(3)coating was 160~200μm.By comparing the structure of samples with different st

关 键 词：碳基体 大气等离子喷涂(APS) 射频磁控溅射(RFMS) 元素扩散 钨 铼 

分 类 号：TG174.4[金属学及工艺—金属表面处理]