Wear resistance of reactive plasma sprayed and laser remelted TiB2–TiC0.3N0.7 based composite coatings against medium carbon steel

• Published in: Applied surface science 2011-01, Vol.257 (7), p.2610-2616
• Main Authors: Mao, Zhengping, Wang, Jun, Sun, Baode, Bordia, Rajendra K.
• Format: Article
• Language: English
• Subjects: Abrasion resistance; Abrasion resistant coatings; Coating; Coatings; Composite coating; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Laser surface treatment; Lasers; Physics; Protective coatings; Reactive plasma spraying; Sliding; Wear mechanism; Wear mechanisms; Wear resistance; Wear tests
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2010.10.031

▶ The wear mechanism of as-sprayed coating at low sliding speed is grain abrasion. ▶ It changes to fatigue failure at higher sliding speed. ▶ The wear resistance of laser treated coatings is better than as-sprayed coatings. ▶ The dominant wear mechanism of laser treated coatings is oxidation. Wear resistance of reactive plasma sprayed TiB2–TiC0.3N0.7 based composite coatings and the as-sprayed coating with laser surface treatment was investigated using plate-on-plate tests. Wear tests were performed at different normal loads and sliding speeds under dry sliding conditions in air. The surface morphologies of counterparts against as-sprayed and laser remelted coatings were investigated. The microstructure and chemical composition of wear debris and coatings were studied using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), respectively. The results show that the wear resistance of the laser remelted coating is improved significantly due to their increased microhardness and reduced flaws. The primary wear mechanism of the remelted coating is oxidation wear and its minor wear mechanisms are grain abrasion and fatigue failure during the course of wear test. In contrast, the primary wear mechanism of the as-sprayed coating is grain abrasion at the low sliding speed (370rpm) and fatigue failure at the high sliding speed (549rpm). The oxidation wear mechanism is a minor contributor for the as-sprayed coating.