| Summary: | 碩士 === 國立東華大學 === 材料科學與工程研究所 === 87 === A complex four-component Ti-Si-C-N system was deposited by the chemical vapor deposition (CVD). Hardness of the Ti-Si-C-N coating was higher than 1,800 kgf/mm2 under the experimental conditions, with a maximum value of 2,800 kgf/mm2. To exploit the Ti-Si-C-N system, other five systems were studied: Ti-N, Ti-C-N, Ti-Si-N, Ti-C, and Ti-Si-C. Five sections was covered in the Ti-Si-C-N system: deposition under the V(C2H2)= 3.4 sccm, deposition under the V(C2H2)= 6.7 sccm, the effect of deposition temperature, the effect of TiCl4 and SiCl4 at 800°C, and the effect of H2 and N2 at 800°C.
The experimental results showed the increased growth rate of TiN with the increase of TiCl4, H2, N2, and deposition temperature. The deposits changed the morphologies with deposition condition, but mostly kept the 1:1 compositional ratio and the hardness of 1,200 kgf/mm2. For the Ti-C-N system, a denser deposit was obtained only at 1000°C. The Ti-Si-N deposits were composed of loosely bound particles that detached the substrate easily.
For the Ti-Si-C-N system, the growth rate of the coatings increased with the flow rate of TiCl4 and SiCl4. The amount of Si component in the deposits decreased with the SiCl4 flow rate under V(C2H2)= 3.4 sccm and low TiCl4 flow rate, but increased under high TiCl4 flow rate. On the opposite way, the amount of Si component in the deposits increased with the SiCl4 flow rate under V(C2H2)= 6.7 sccm and low TiCl4 flow rate, but decreased under high TiCl4 flow rate. The Ti-Si-C-N deposits could be obtained at as low as 800°C with their properties depending on the deposition conditions. In addition to the effect of TiCl4 and SiCl4, the H2 and N2 also played a role in this Ti-Si-C-N deposition. The Ti-Si-C-N coatings could be successfully deposited only under the high inputs of H2 and N2. For the TiC and Ti-Si-C systems, deposition temperature had a little influence on the growth rate, but could change the deposit microstructure. Deposition temperature also had a little influence on the deposit composition for the Ti-C system, but had an influence for the Ti-Si-C. Both of the systems could have a hardness of 3,000 kgf/mm2 under a proper deposition condition.
|
|---|
