Papers by Author: Fan Tao Meng

Abstract: Chemical vapor deposition (CVD) is an effective method of preparing silicon carbide whiskers or films and chemical vapor infiltration (CVI) can be successfully used as the preparation of SiC composites. In this paper, silicon carbides whiskers were firstly deposited on substrates of RB-SiC by CVD process and then silicon carbide composites were prepared by chemical vapor infiltration in the SiC whiskers in an upright chemical vapor deposition furnace of Φ150mm×450mm with methyltrichloride silicane (MTS) as precursor gas, H2 as carrier gas and Ar as dilute gas. The morphologies of the SiC whiskers grown on RB-SiC substrate and SiC composites infiltrated in SiC whiskers were determined by scanning electron microscope (SEM), and the crystalline phase of the final deposits were confirmed with X-ray diffractometry (XRD) As a result, the curly defects of whiskers decrease with the addition of dilute gas. And by chemical vapor infiltration in SiC whiskers the, SiC composites were successfully prepared. Finally the deposits were determined as β-SiC.

Abstract: Silicon carbide prepared by chemical vapor deposition (CVD) is one of the important candidate materials for space mirror and high-power mirror such as laser mirror, because of its superior performances such as low density, high melting point and homogeneity. In this paper, the SiC coatings were deposited on the substrates of reaction bonded silicon carbide (RB-SiC) by CVD process. Then, the morphologies of the deposits were examined with scanning electron microscopy. The crystalline phase of the as-deposited films was confirmed with X-ray diffractometry. And the adhesion between the CVD film and the substrate was rated with scraping method. As a result, the morphologies of the deposits, i.e. whiskers at 1050°C or films at 1100°C, are different from that of the substrate. And the mean diameter of the deposits at 1100°C is larger than that at 1050°C. Furthermore, the crystalline phase of the as-deposited film is determined as β-SiC and the adhesion is firm enough not to be peeled off with the scraping test.

Abstract: Silicon carbide is one of the best materials for satellite mirror and chemical vapor deposition (CVD) is an effective method of preparing SiC whiskers and films. In this paper, SiC whiskers or films were deposited on substrates of RB-SiC in an upright chemical vapor deposition furnace of Φ150mm × 450 mm with methyltrichloride silicane (MTS) as precursor gas and H2 as carrier gas under dilute gases of different H2/Ar ratio and different deposition temperature between 1050°C and 1150°C. The morphology and composition of the CVD-SiC grown on RB-SiC substrate were determined by scanning electron microscope (SEM) and X-ray diffraction (XRD) respectively. As a result, whisker-like, worm-like or ball-like SiC can be respectively obtained dependent on different deposition conditions such as H2/Ar ratio and deposition temperature, and the composition of the productions are determined as β-SiC by XRD. Furthermore, the deposition mechanisms of different morphologies of SiC are introduced.