Improved High Temperature Tensile Properties of Ti-6Al-4V Alloy by Plasma Sprayed Coating
A zircon coating was applied on the surface of Ti-6Al-4V alloy by plasma spray and its effect on the high temperature tensile properties of the alloy as well as the oxidation behavior of the alloy were studied. Tensile tests were conducted at 850°C with different strain rates of 10-4s-1,10-3s- 1, 10-2s-1 and 10-1s-1. The results show that the elongation of the coated specimens is higher than that of the uncoated ones, while the ultimate tensile strength of the alloy is not changed. An oxide film had formed on the surface of uncoated Ti-6Al-4V alloy, however no such oxide film was found on the coated alloy at the early of stage. The coating can prevent oxygen penetration into the substrate thus prevent embrittlement of the subsurface zone. The ductility could be improved by means of the zircon coating. The optical micrographs of the specimens show little change in microstructures of the coated and uncoated specimens. Zircon coating has no effect on the microstructure of the substrate alloy.
Changhee Lee, Jong-Bong Lee, Dong-Hwan Park and Suck-Joo Na
C. Li et al., "Improved High Temperature Tensile Properties of Ti-6Al-4V Alloy by Plasma Sprayed Coating", Materials Science Forum, Vols. 580-582, pp. 547-550, 2008