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| Abstract No.: |
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Scheduled at:
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Friday, May 23, 2014, Hall H3 9:40 AM
New Processes
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| Title: |
Advanced UHP/HVOF gun using ethanol fuel
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| Authors: |
Frantisek Zahalka / Flame Spray Technologies BV, The Netherlands
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| Abstract: |
The article is dedicated to evaluation of properties of ultra-high pressure high velocity oxy fuel gun, using ethanol as the fuel. A revolutionary design in the area of the combustion chamber allows a more efficient burning process and a much higher burning gas velocity than conventional HP/HVOF. Combustion chamber pressures up to 13 bars offers preparation of the thermally sprayed coating with unique physical and mechanical properties with 50% less oxygen consumption. In this paper, a design of experiment (DOE) was used to evaluate dependence of the particle temperature and velocities for different combustion pressures and spray distances for WC and CrC based materials and to help creation of the process maps of particle velocities and temperatures for different combustion pressures and alpha combinations. Additionally, base mechanical properties of thermally sprayed WC based coating sprayed by UHP/HVOF ethanol gun are evaluated and presented. Average particle velocity as measured by the SprayWatch apparatus was 797 m/s and 857 m/s for WC based powder and CrC based powder, respectively. The DOE results have confirmed strong dependence of the particle velocity on combustion chamber pressure and spray distance. Surprisingly, the deposition distance has been determined to be the intrinsic factor for particle temperature. The F/O ratio (alpha) was determined as a negligible factor for particles temperature control. Results of WC based coating mechanical properties have confirmed excellent coating quality, comparable with standard JP-5220 kerosene gun.
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