(1. 中南大學(xué) 粉末冶金研究院，長沙 410083；
2. 安陽工學(xué)院，安陽 455000)
摘 要: 采用熱蒸鍍-原位反應(yīng)法制備Mo-Si-X-C(X=Al, Ti)碳基陶瓷涂層。利用X射線儀、掃描電子顯微鏡和納米壓痕測試儀對涂層的微觀結(jié)構(gòu)和力學(xué)性能進行表征，研究成分及熱蒸鍍工藝參數(shù)對涂層的物相組成、微觀結(jié)構(gòu)和力學(xué)性能的影響，并揭示涂層的形成機制。結(jié)果表明：不同組分蒸鍍母料在1550 ℃、Ar氣氛條件下，由于不同蒸氣壓誘發(fā)各異的擴散路徑，從而使原位反應(yīng)生成Mo-Si-X-C(X=Al,Ti)復(fù)相陶瓷涂層的形貌、相成分及分布明顯不同。添加Ti和Al元素有利于分別生成(Ti0.8Mo0.2)Si2相和Mo(Si, Al)2相，促進熱蒸鍍過程；隨著溫度的升高，基體表面Si黏性減弱，同時流動性增強，涂層中鉬硅化物消失；1800 ℃真空環(huán)境下涂層中的SiC晶粒異常長大，破壞涂層結(jié)構(gòu)，導(dǎo)致涂層失效。力學(xué)性能表明：同時添加Al、Ti元素，形成復(fù)雜多相界面結(jié)構(gòu)的23Mo-63Si-7Ti-7Al陶瓷涂層的力學(xué)性能最優(yōu)，其抗壓強度達到19.584GPa，顯微硬度達到1848HV及彈性模量達到255.124 GPa。
關(guān)鍵字: 熱蒸鍍法；原位反應(yīng)法；SiC；(Ti0.8Mo0.2)Si2；涂層；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
