The Structure and Properties of a-C:Ti and a-C:Ti:N Coatings Deposited on a Titanium and Titanium Nitride Sublayer

EasyChair Preprint 4569

Abstract

In this work, were deposited Ti(TiN)/a-C:Ti(TiN) coatings doped by titanium and nitrogen atoms on steel 316L and Si substrates to study the microstructures and mechanical properties. The coatings were obtained, using titanium cathode D.C. and graphite target pulse arc sputtering under Nitrogen pressure of 10-1 Pa. The phase composition in the coatings were studied by XPS and Raman spectroscopy. XPS results showed that Ti-C bonds formed in the Ti/TiN/a-C:Ti coating, while Ti-N, Ti-C, C–N bonds were observed in Ti/TiN/a-C:Ti:N coatings. Raman spectroscopy exhibited that the doped titanium layers into a-C coatings decrease the size of Csp2 clusters. An increased disordering was also observed in Csp2 clusters, which is important for the mechanical properties. The surface microstructure of coatings were further characterized by AFM, which indicated strong dependences on the dropled phase, grain size and its nature (such as graphite, titanium carbide, titanium carbonitride) of the coating. The microhardness of coatings raised up to 12,5 GPa. The doped titanium layers led to a decrease in internal stresses in Ti/TiN/a-C:Ti, i.e., 108,1 MPa. The friction coefficient is less than 0.3, which is dependent on the presence of Ti atoms in a-C coatings. Resudial stresses are reduced due to the introduction of alloying elements, as well as the presence of layers of soft metal layers in the coating structure. The change in the sp2/sp3 ratio determines the change in the values of microhardness and kinetics of friction.

Keyphrases: Friction, Hardness, Nitrides, XPS, carbon coatings, morphology, structure

@booklet{EasyChair:4569,
  author    = {Xiaohong Jiang and D. G. Piliptsou and A. V. Rogachev and E. A. Kulesh and Yiming Liu},
  title     = {The Structure and Properties of a-C:Ti and a-C:Ti:N Coatings Deposited on a Titanium and Titanium Nitride Sublayer},
  howpublished = {EasyChair Preprint 4569},
  year      = {EasyChair, 2020}}