石墨表面TaC涂层的熔盐法制备及表征  

Preparation and Characterization of TaC Coating on Graphite via Molten Salt Method

作　　者：董天下 孟凡桂[1] 陈红梅 张九阳[4] 高超 王宗玉 DONG Tian-xia;MENG Fan-gui;CHEN Hong-mei;ZHANG Jiu-yang;GAO Chao;WANG Zong-yu(School of Materials Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China;Hunan Provincial Key Laboratory of Fine Ceramics and Powder Materials,Hunan University of Humanities,Science and Technology,Hunan Loudi 417000,China;Hunan International Economics University,Changsha 410205,China;SICC Co.,Ltd.,Jinan 250000,China)

机构地区：[1]中南林业科技大学材料科学与工程学院,长沙410004 [2]湖南人文科技学院精细陶瓷与粉体材料湖南省重点实验室,湖南娄底417000 [3]湖南涉外经济学院,长沙410205 [4]山东天岳先进科技股份有限公司,济南250000

出　　处：《表面技术》2023年第2期297-306,共10页Surface Technology

摘　　要：目的以K2TaF7和Ta粉为主要原料,在石墨材料表面制备TaC涂层。方法反应物在1200℃的熔盐体系中保温3h,反应生成碳化物,经后续2300℃真空保温1h后,得到TaC涂层材料。采用XRD和SEM对涂层的组成结构进行表征,采用拉开法对涂层的和石墨基体的结合强度进行测量,采用纳米压痕对涂层的硬度和弹性模量进表征,最后对TaC涂层的抗腐蚀性能进行模拟测试评估和实际的SiC长晶测试。结果熔盐法制备的TaC涂层连续地覆盖在石墨表面,保持了原始石墨的形貌,其物相组成为TaC,呈现出亮黄色,厚度为20~40μm,涂层的晶粒无择优取向生长,呈现出无序堆积的状态。TaC涂层与石墨基体的结合强度为9.49 MPa,硬度和弹性模量分别为14.42 GPa和123.32 GPa。TaC涂层样品于2300℃的SiC腐蚀气氛环境下保温3 h,质量损失率仅为0.01 g/(m^(2)·h),远低于同测试条件下无涂层石墨样品的质量损失率4.67 g/(m^(2)·h)。在2300℃氩气气氛下保温3 h的SiC粉包埋TaC涂层的接触腐蚀试验中,SiC和TaC涂层的界面清晰,没有发生相互的扩散。TaC涂层部件应用于2000℃以上保温150 h以上的SiC单晶的生长制备后,涂层部件总体形貌保持完整,部件边缘棱角区域出现了脱落,但其他部位的TaC涂层仍和基体结合良好,涂层在长晶过程中的质量损失率约为0.41g/(m^(2)·h),表现出良好的抗腐蚀性能。结论熔盐法制备石墨表面TaC涂层的工艺简单、成本低、效率高,可制备曲面等不规则的构件。制备的TaC涂层晶粒堆积紧密,没有发生择优取向,与石墨基体的结合强度高,在侵蚀性的环境中,能减弱侵蚀性气体对石墨基体的侵蚀,有望在第三代半导体的制备中得到应用。本研究不仅提供了一种在石墨基体上制备TaC抗腐蚀涂层的方法,也提供了一种在其他碳材料上制备TaC涂层的方法。The work aims to prepare the TaC coating on the surface of graphite material with K2TaF7and Ta powder as the main raw materials,which is of great value for reducing the preparation cost and improving the quality of third-generation semiconductors such as SiC,Gan,and AlN.TaC coating was synthesized on the surface of the graphite substrate by chemical reactions in molten salt at 1200℃ for 3 h followed by high-temperature heat treatment of vacuum at 2300℃ for 1 h.The phase composition and microstructure of the coating were characterized by XRD and SEM.The interface bonding strength between the TaC coating and the graphite substrate was measured by the pull-off method.The hardness and elastic modulus of the coating were characterized by nanoindentation.Finally,the corrosion resistance of the TaC coating was evaluated under simulated conditions and the TaC coated graphite was applied to the SiC crystal growth.The TaC coating prepared via molten salt method continuously covered the surface of the graphite and the surface morphology of the TaC coating was consistent with that of the original graphite substrate,with a bright yellow color.The phase composition of the coating was TaC and the thickness of the coating was about 20-40μm.The TaC coating had a non-textured granular structure without preferred orientation growth.The interface bonding strength between the TaC coating and the graphite substrate was 9.49 MPa.The hardness and elastic modulus of the TaC coating were 14.42 GPa and 123.32 GPa,respectively.The mass loss rate was only 0.01 g/(m^(2)·h)after the TaC coated graphite sample was kept at 2300℃for 3 h in SiC corrosion environment,which was much lower than that of uncoated graphite sample of 4.67 g/(m^(2)·h)under the same test conditions.In the contact corrosion experiment with TaC coated graphite embedded by SiC powder at 2300℃argon for 3 h,the interface between SiC and TaC coating was clear and there was no mutual diffusion.After the TaC coated graphite was applied to the growth of SiC single crysta

关 键 词：熔盐法 高温热处理 石墨 TAC涂层 耐腐蚀性 

分 类 号：TG174[金属学及工艺—金属表面处理] TB304[金属学及工艺—金属学]