| Title |
Research Paper / Surface Treatment : Formation of Ti(NCO) Coatings by MO-PACVD I. Effect of Process Parameters on the Coatings Properties |
| Authors |
유홍재(Hong Jae Yoo); 김선규(Sun Kyu Kim) |
| Abstract |
Process parameters of PACVD process using titanium tetraisopropoxide(Ti(C₃H_7O)₄) organic compound precursor as metal donor instead of TiCl₄ were investigated to deposit the Ti-base hard layer on tool steel surface in order to decrease the deposition temperature and improve the step coverage of substrate with complicate shape. Ti(NCO) composite layer was deposited on tool steel by MO-PACVD process at approximately 500℃ using gas mixture of titanium tetraisopropoxide, hydrogen and nitrogen. Process parameters such as precursor volume %, substrate temperature and H₂/N₂ gas ratio were optimized. Deposited layers were characterized in terms of hardness, surface morphology, corrosion resistance and composition. Layers of good quality were obtained when the content of Ti(C₃H_7O)₄ vapor in the gas mixture was lower than 5%. The layer obtained with H₂/N₂ gas ratio of 1:1 showed the highest hardness of 1645H_(v0.05). The layers had lower hardness when using H₂/N₂ gas ratio of 7:3 and 3:7. The layer obtained at 500-550℃ with H₂/N₂ gas ratio of 1:1 had good corrosion resistance. |