ABSTRACT
Titanium is one of the most promising metals in the field of high specific strength engineering. Titanium alloys primarily stand out because of two properties: high specific strength and excellent corrosion resistance. This also explains their preferential use in the aerospace sector, the chemical industry, medical engineering, and the leisure sector. Their property has been degraded in wear inducing environments, which could be protected by various surface engineering methods. Thermal spray coating is one of the unique methods employed to enhance wear properties. The titania (TiO2) with secondary phase ultrafine particles, such as silicon carbide (SiC), gives excellent protection against wear environment. Titania, with various volume percentage of SiC coatings, were developed on titanium substrate using high velocity oxy fuel (HVOF) spraying. Fused and crushed TiO2 feedstock was deposited on titanium substrate. The coating cross section was observed using optical microscope, and porosity analysis was also conducted using image analysis technique. The abrasive wear testing was conducted in a dry sand rubber wheel (DSRW) tester as per ASTM G65 standard. The dry sand rubber wheel test involved abrading a standard specimen with the grit of controlled size composition. The abrasive was introduced between test specimen and a rotating wheel with a chlorobutyle rubber tyre of diameter 228.6x12.7 mm wide and hardness A-60 durometer. The test specimen size 76 x 25.4 x 12.7 (l x b x w) was pressed against a rotating wheel at a specified force by means of lever arm, while a controlled flow of grit abradeed test surface. In this test, AFS 50/70 Quartz grain sand was used as the abradent. The test was conducted on uncoated and coated specimens, and worn surfaces were analysed.
