Adhesion, Residual Stresses and Tribology of Rf Sputter Deposited Titanium Carbide Coatings

Mechanical properties of surface hard coatings depends strongly on both the adhesion of the coating to the substrate as well as the sign and magnitude of the residual stress in the coating. The residual stress in sputter deposited TiC films was found to be compressive and could be related to the trapped Ar concentration in the films. The Ar concentration, and hence the compressive stress, increased with decreasing Ar sputtering pressure, P(,Ar), due to the relationship between the substrate induced potential, V(,i), and P(,Ar). High compressive stress in the TiC films enable this brittle material to withstand high tensile strain. However, too high a compressive stress would induce a high Poisson tensile stress which result in the fracture of the interface and the bulging up of the film. Incorporation of moderate amount of oxygen in the TiC films during deposition will not cause compressive stress. However, high oxygen content in the film with O/Ti higher than 0.5 would lead to second phase segregation in the TiC(,x)O(,1-x) matrix and result in a high compressive stress.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Pan, Alfred I-Tsung

• Engineering, Materials Science

Language dc:language

eng

Identifier

(UMI)AAI8114456

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/67031