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| Abstract No.: |
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| Title: |
Numerical analysis of arc and jet behavior of supersonic plasma spraying by a DC plasma torch with a laval anode
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| Authors: |
Chang-Jiu Li* / Xi'an Jiaotong University, P.R. China
Shan-Lin Zhang / State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, China
Cheng-Xin Li/ State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, China
Guan-Jun Yang/ State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, China
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| Abstract: |
It is well known that the particle temperature and velocity have significant influences on the coating structure and properties during plasma spraying process. The dense coatings can be deposited with the molten particles of a high velocity. In this study, in order to increase the particles velocity, a DC plasma torch with a laval-type anode nozzle was used to produce the supersonic plasma jet. The plasma arcing behavior inside the laval anode nozzle is simulated by numerical methods. A simplified analytical model is formulated to investigate the influences of anode structure on the arc behavior and plasma jet properties. The effect of arc current and gas flow rate on the plasma arc and jet characteristics is examined. Moreover, the accelerating and heating behavior of spray particles within the supersonic plasma jet are investigated by numerical analysis. For comparison, the temperature and velocity of spray particles at different conditions were measured by Spraywatch system to verify the numerical results. The results show that the particle velocity and temperature estimated using the present simulation method are reasonably consistent with the observed results. The relationships between microstructure and properties of the coatings and particle parameters are examined.
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