|
6850 |
|
A challenge for preparing dense titanium coatings with nitrogen gas in cold spraying |
|
ChunMing Deng / Guangdong Institute of New Materials, P.R. China K. J. Zhang / Guangdong Institute of New Materials, J. Huang/ Guangdong Institute of New Materials, R. Z. Huang*/ Guangdong Institute of New Materials, P.R. China M. Liu Liu/ Guangdong Institute of New Materials, K. S. Zhou/ Guangdong Institute of New Materials, |
|
Titanium and its alloys are relatively difficult to form a dense (porosity under 1.0%) coating with cold spray technology. Usually, helium is utilized as the working gas to deposit them in order to get denser coating despite the higher cost. Therefore, it is a challenge to deposit the dense titanium coatings with nitrogen gas. In this paper, three types of pure titanium powder with different particle sizes (5 ~ 25 ¼m, 25~45 ¼m and 5~45 ¼m) were cold sprayed with cheaper nitrogen gas. The influences of gas pressure and temperature on the coating properties (microstructure, hardness and etc.) were discussed. The experimental results show that titanium powders with size of 5~45 ¼m would form denser coatings with the porosity less than 0.3% at the gas pressure and temperature up to 5MPa and 950. And the microhardness of the coating can get to 171 HV0.3. The studies show that a preparation for high-quality cold-sprayed titanium coatings with low-cost could be realized with the optimized spray conditions and feedstock. Keywords: cold spray; titanium coatings; low-cost; microhardness; particle size |