The Effect of Microstructural Change of DLC Films by Annealing on Their Corrosion and Wear Properties
김성완 Sung Wan Kim , 조용기 Yong Ki Cho , 장우순 Woo Soon Jang , 김상권 Sang Kweon Kim
Abstract
DLC(a-C:H) films were deposited on STD11 steel and Si(100) substrates by Pulsed DC PECVD method using Ar and C2H2 gaseous mixture at room temperature. Before the DLC deposition, the a-Si:C:H inter-layer was deposited on substrates using Ar and TMS(Tetra Methyl Silane) source. As deposited DLC films were annealed at 300℃ to 700℃ under ambient air and vacuum conditions during an hour. We observed that DLC films thickness was decreased by hydrocarbon species effusion from DLC surface and creaks formed on surface over 600℃ Furthermore found out that microstructural change of DLC films with an increasing temperature. In Raman analysis, the G peaks position shifted to graphite peak position and I(D)/I(G) ratio increased with an annealing temperature. XPS analysis revealed that carbon bonding structures changed sp3 to sp2 under air and vacuum conditions. Those mean that DLC films by heating up continuously become to "graphite-like" structures. This was related to wear behavior and corrosion resistance properties of DLC films. Wear properties of annealed DLC films under both conditions grew worse with an increasing temperature such as worn out the DLC film. Corrosion resistances of annealed DLC films also were inclined to decreasing by structure changes.
Key Words
DLC, annealing, microstructure, wear behavior and corrosion resistance