石墨表面双辉等离子Ta/TaC涂层抗热震性能研究  

Thermal Shock Resistance of Double-glow Plasma Ta/TaC Coating on Graphite Surface

作　　者：王彦 杨凯 吕绪明 党博 魏东博[1] 张平则[1] WANG Yan;YANG Kai;LYU Xuming;DANG Bo;WEI Dongbo;ZHANG Pingze(School of Material Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Research Institute of Physical and Chemical Engineering of Nuclear Industry,Tianjin 300180,China;Science and Technology on Particle Transport and Separation Key National Defense Laboratory,Tianjin 300180,China)

机构地区：[1]南京航空航天大学材料科学与技术学院,南京210016 [2]核工业理化工程研究院,天津300180 [3]粒子输运与富集技术国防科技重点实验室,天津300180

出　　处：《材料导报》2024年第23期42-50,共9页Materials Reports

摘　　要：为了改善石墨电极表面涂层与基体间因力学性能及热膨胀系数差异而导致的热失配问题,采用双层辉光等离子表面渗金属技术在石墨表面分别制备了Ta、TaC涂层和Ta/TaC复合涂层。XRD结果表明,Ta涂层表面物相主要由Ta、Ta_(4)C_(3)和Ta_(2)C构成,TaC和Ta/TaC涂层表面为纯TaC相。SEM结果表明,所有涂层均由涂层-基体互扩散层和表面沉积层组成,且内部均匀致密。相较于TaC物相,Ta单质更容易扩散进入石墨基体;相同条件下TaC在Ta上生长速率更快。力学性能测试结果表明,Ta涂层作为TaC涂层和石墨之间的过渡层,因其良好的物理缓冲作用能够有效提高TaC涂层与基体的结合强度和显微硬度。热震结果表明,在室温与650℃之间循环40次后,单层TaC涂层因极大的应力失配产生严重崩裂而剥落;Ta/TaC复合涂层因Ta过渡层的存在有效缓解了冷热循环过程中的应力失配问题,热冲击后表面未发现裂纹且膜基界面结合依旧良好,涂层的抗热冲击性能得到显著提高。In order to alleviate the thermal mismatch between the graphite electrode surface coating and the substrate due to the disparity in mechanical properties and coefficient of thermal expansion,Ta,TaC and Ta/TaC coatings were prepared on the graphite surface by double-glow technology.XRD results show that the surface phase of Ta coating is mainly composed of Ta,Ta_(4)C_(3)and Ta_(2)C,while the surface of TaC and Ta/TaC coating is pure TaC phase.SEM results show that all coatings are composed of interdiffusion layer and surface deposition layer,and the interior is uniform and dense.Compared with TaC,Ta is easier to diffuse into the graphite,and TaC is easier to grow on Ta under the same conditions.The mechanical properties test results show that Ta coating can effectively improve the binding quality and microhardness of TaC coating and substrate because of its excellent physical buffering effect.The thermal shock results show that the single-layer TaC coating is spalling se-riously due to great stress mismatch after 40 times of cycles between room temperature and 650℃.Ta/TaC composite coating can effectively alleviate the stress mismatch in the process of cold and hot cycling due to the existence of Ta transition layer.No cracks are found on the surface and the film-base interface is still good.The thermal shock resistance of the composite coating is significantly improved.

关 键 词：石墨电极 碳化钽 复合涂层 双辉 抗热震性能 

分 类 号：TB332[一般工业技术—材料科学与工程] TB304