Friction and wear behaviour of carbon nitride films deposited on plasma nitrided Ti–6Al–4V

• Published in: Wear Vol. 237; no. 1; pp. 12 - 19
• Main Authors: Fu, Yongqing, Loh, Nee Lam, Wei, Jun, Yan, Bibo, Hing, Peter
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 2000; Amsterdam Elsevier Science; New York, NY
• Subjects: Adhesion strength; Amorphous carbon nitride; Applied sciences; Bearings, bushings, rolling bearings; Contact of materials. Friction. Wear; Drives; Duplex treatment; Exact sciences and technology; Mechanical engineering. Machine design; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Nonmetallic coatings; Plasma nitriding; Production techniques; Surface treatment; Ti–6Al–4V; Tribology; Plasma nitriding; Ti–6Al–4V; Amorphous carbon nitride; Duplex treatment; Tribology; Adhesion strength; Plasma treatment; Wear test; Bearing(mechanics); Nitriding; Amorphous state; Alloy-Ti90Al6V4; Experimental study; Non metal coating; Titanium base alloys; Surface treatment; Dry friction; Duplex process; Load capacity; Scratch; Wear; Friction coefficient; Carbon nitrides; Wear resistance; Sliding friction
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/S0043-1648(99)00313-0

Amorphous carbon nitride (CN x ) films were deposited on plasma nitrided Ti–6Al–4V substrate in order to improve the adhesion strength and tribological behaviour. Scratch and ball-on-disk wear tests were performed to evaluate the load bearing capacity, wear and friction characteristics of the duplex-treated coatings. Compared with a CN x film deposited on Ti–6Al–4V substrate, the load bearing capacity of a CN x film deposited on plasma nitrided layer was improved dramatically. Results showed that under dry sliding condition, the duplex-treated system was more effective in maintaining a favourable low and stable coefficient of friction and improving the wear resistance than both individual plasma nitriding and CN x film on Ti–6Al–4V substrate. The reasons for this significant improvement in tribological behaviour with the application of duplex treatment can be attributed to the combined benefits from both plasma nitriding and CN x films. (1) Plasma nitriding of Ti–6Al–4V produces a graded hardened case which serves as an excellent supporting and load bearing layer for hard CN x films. (2) The CN x film deposited at low temperature can produce a wear resistant and low-friction surface without impairing the beneficial effects from plasma nitriding treatment, and the smooth CN x films could effectively reduce both the interfacial stresses and the stresses near the surface thus providing a good tribological behaviour. (3) The graphitisation of the wear debris during dry sliding condition can help to decrease the coefficient of friction and improve the wear resistance.