Spraying of TiN by a Combined Laser and Low Pressure Plasma Spray System(Physics, Process, Instruments & Measurements)
Search this Article
The formation of a TiN-Ti composite coating by thermal spraying of Ti powder with laser processing of the subsequent coating in a low pressure N_2 atmosphere was examined. A thermal spraying system of a low pressure plasma jet for thermal spraying combined with a CO_2 laser was used. Firstly, the coating was plasma-sprayed onto a mild steel substrate using a N_2 plasma jet and Ti powder in a controlled low pressure N_2 atomosphere. The coating was then irradiated with a CO_2 laser beam in a N_2 atomsphere with the coating heated by a N_2 plasma jet. The amount of TiN formed in the coating was characterized by X-ray diffraction analysis. The influence of plasma spraying conditions such as plasma power, flow of plasma operating gases, chamber pressure and laser-irradiating conditions on the formation of TiN was investigated. The effect of TiN formation in the Ti coating on Vickers hardness of the coatings was examined. It was evident that coating hardness was increased with an increase in TiN content in the coating and a TiN-Ti composite coating of a hardness of over 1200Hv can be obtained with the assistance of laser-irradiation processing.
- Transactions of JWRI
Transactions of JWRI 21(1), 51-56, 1992-06