Show simple item record

dc.contributor.advisorYang, Qiaoqinen_US
dc.creatorZhang, Chunzien_US
dc.date.accessioned2015-10-24T12:01:11Z
dc.date.available2015-10-24T12:01:11Z
dc.date.created2014-05en_US
dc.date.issued2015-10-23en_US
dc.date.submittedMay 2014en_US
dc.identifier.urihttp://hdl.handle.net/10388/ETD-2014-05-1547en_US
dc.description.abstractTitanium (Ti) and its alloys have been widely used in aerospace, biomedical, chemical processing, marine facilities, and sports equipment because of their low density, very high tensile strength and toughness, and high corrosion resistance. However, the poor tribological properties has been a major problem and limited their widespread applications. Deposition of wear/corrosion resistant diamond-like carbon (DLC) coatings on Ti alloys is promising to significantly enhance the durability and service performances of these materials. However, the adhesion between DLC coatings and Ti alloy substrates is too weak to meet the application requirements. Up to now, approaches including optimization of deposition conditions, surface treatment of the substrate, deposition of an interlayer, and incorporation of metallic or nonmetallic elements have been used for adhesion enhancement of DLC on Ti alloys. In this research, a new method, nanodiamond particles incorporation, was developed for adhesion enhancement of DLC coatings on Ti alloys. In order to achieve high diamond nucleation without damaging the Ti alloy, nucleation enhancement of diamond on Ti alloys by nanodiamond seeding, tungsten (W) interlayers, and high methane concentration were studied. Diamond, DLC and W deposition were carried out by microwave assisted chemical vapor deposition, direct ion beam deposition and hot filament assisted chemical vapor deposition, respectively. Scanning electron microscopy, Atomic force microscopy, X-ray diffraction, Raman spectroscopy and synchrotron-based near edge extended X-ray absorption fine structure spectroscopy were used to characterize the microstructure and chemical bonding of the as-deposited particles and films, and indentation testing was used to evaluate the adhesion of the as-deposited coatings. By nanodiamond seeding or applying a W interlayer, significantly enhanced diamond nucleation has been obtained on Ti alloys, and consequently high quality nanocrystalline diamond thin films have been obtained on Ti alloys at decreased deposition temperature and reduced deposition time, which mitigates the deterioration of Ti alloy substrates due to hydrogen diffusion during diamond deposition and also enhances the adhesion of diamond on Ti alloys. Based on these results, nanodiamond particles (NDP) with high nucleation density and high adhesion were deposited on Ti alloys initially to enhance the adhesion of DLC films on Ti alloys. Results show that the pre-deposited NDP can significantly increase the adhesion of DLC on Ti6Al4V, probably due to the increased interfacial bonding, mechanical interlocking, and stress relief by the incorporation of NDP into DLC to form NDP/DLC composite films.en_US
dc.language.isoengen_US
dc.subjectdiamond, diamond-like carbon, Ti alloy, adhesionen_US
dc.titleADHESION ENHANCEMENT OF DIAMOND AND DIAMOND-LIKE CARBON THIN FILMS ON TITANIUM ALLOYen_US
thesis.degree.departmentMechanical Engineeringen_US
thesis.degree.disciplineMechanical Engineeringen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophy (Ph.D.)en_US
dc.type.materialtexten_US
dc.type.genreThesisen_US
dc.contributor.committeeMemberHedayat, Assemen_US
dc.contributor.committeeMemberSzpunar, Jerzy A.en_US
dc.contributor.committeeMemberJohnston, James D.en_US
dc.contributor.committeeMemberChen, Weixingen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record