(1. 中南大学 粉末冶金研究院，长沙 410083；
2. 安阳工学院，安阳 455000)
摘 要: 采用热蒸镀-原位反应法制备Mo-Si-X-C(X=Al, Ti)碳基陶瓷涂层。利用X射线仪、扫描电子显微镜和纳米压痕测试仪对涂层的微观结构和力学性能进行表征，研究成分及热蒸镀工艺参数对涂层的物相组成、微观结构和力学性能的影响，并揭示涂层的形成机制。结果表明：不同组分蒸镀母料在1550 ℃、Ar气氛条件下，由于不同蒸气压诱发各异的扩散路径，从而使原位反应生成Mo-Si-X-C(X=Al,Ti)复相陶瓷涂层的形貌、相成分及分布明显不同。添加Ti和Al元素有利于分别生成(Ti0.8Mo0.2)Si2相和Mo(Si, Al)2相，促进热蒸镀过程；随着温度的升高，基体表面Si黏性减弱，同时流动性增强，涂层中钼硅化物消失；1800 ℃真空环境下涂层中的SiC晶粒异常长大，破坏涂层结构，导致涂层失效。力学性能表明：同时添加Al、Ti元素，形成复杂多相界面结构的23Mo-63Si-7Ti-7Al陶瓷涂层的力学性能最优，其抗压强度达到19.584GPa，显微硬度达到1848HV及弹性模量达到255.124 GPa。
关键字: 热蒸镀法；原位反应法；SiC；(Ti0.8Mo0.2)Si2；涂层；碳基材料
（1. State key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China;
2. Anyang Institute of Technology, Henan 455000, China）
Abstract:Mo-Si-X-C (X = Al, Ti) ceramic coatings were prepared by thermal evaporation—in situ reaction in order to investigate the impact of different process parameters and compositions on the microstructure and its mechanism. The phase compositions, microstructural features and micro-mechanial properties were studied by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and commercially available micro-indentation device (CSM), respectively. The results show that, the differences of the morphology, phase composition and distribution are attributed to different diffusion paths of various masterbatches at 1550 ℃ in argon. Adding Ti and Al elements is beneficial for the forming of the (Ti0.8Mo0.2)Si2 and Mo(Si, Al)2, respectively, which can accelerate their evaporation process. As temperature increases to 1800℃, the fluidity of the surface Si increases, however, its viscosity decreases, accompanied by disappearance of molybdenum silicon. Further research shows that SiC grains will grow up unusually, destroy the coating structure and finally lead to coating failure when the atmosphere changes to vacuum. The mechanical properties show that adding Al and Ti elements simultaneously to the masterbatches, the 23Mo-63Si-7Ti-7Al ceramic coating shows the highest value. The compressive strength reaches to 19.584 GPa, hardness reaches 1848HV and elastic modulus reaches 255.124 GPa.
Key words: thermal evaporation; in situ reaction; SiC; (Ti0.8Mo0.2)Si2; coating; carbon-based material
