摘要
以MTS为先驱体原料,在950-1300℃、负压条件下沉积了CVD SiC涂层．利用SEM对涂层的表面形貌和断口特征进行了表征．沉积温度和SiC涂层表面形貌的关系如下:950℃时,沉积的SiC颗粒非常细小,为独立的球形堆积;1000-1100℃时,CVD SiC涂层表面光滑、致密;1150-1300℃沉积的SiC涂层呈现出球状或瘤状结构且表面粗糙．结合热力学和晶体形核-长大理论,研究了沉积温度对SiC涂层表面形貌的作用机制．沉积温度和SiC涂层断口形貌的关系如下:1200℃以下沉积的SiC涂层断面致密、无孔洞;而1300℃沉积的SiC涂层断面非常疏松．利用岛状生长模型揭示了SiC涂层内部显微结构的形成机理．
The coatings of SiC were prepared from the methyltrichlorosilane （MTS） by low pressure chemical vapor deposition from 950℃ to 1300℃. SEM was used to characterize the surface and crosssectional morphologies of the as deposited coatings. The effects of temperature on the microstructures of SiC coatings were investigated. At 950℃, the as-deposited SiC coating is loose and the grains of the coating are fine. In the temperature range of 1000-1100℃, CVD SiC coatings show a dense and smooth surface morphology. However, in the temperature range of 1150-1300℃, the surface morphology of SiC coatings changes to rounded hillocks and the as-deposited coatings are very rough. Factors influencing the surface morphologies and structures of SiC coatings were studied through thermodynamics and nucleation-growth theory. The relationship between deposition temperature and SiC coatings＇ cross-sectional morphologies can by listed as follows, the as deposited coatings are very dense and there are no holes when the deposition temperature is lower than 1200℃, however, the as deposited coatings become very loose at 1300℃. The inside structures of SiC coatings were interpreted by the island growth model.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第1期153-158,共6页
Journal of Inorganic Materials
关键词
化学气相沉积
SIC
温度
涂层
显微结构
chemical vapor deposition
SiC
temperature
coatings
microstructure
