Posted by Hong Wang (207.54.105.185) on 13:00:47 08/03/06
In Reply to: Effect of Sub-Micron particles and Oxides on HVOF posted by Ken Watson
Hi Ken,
Each HVOF system has its own optimized particle size distribution
range depending on the flame temperature, nozzle design, powder
feeding system, etc. I don't know if there is any general size
range good to all the systems.
Generally, small particle size results in denser coating but more
chances to get oxdized due to large exposed area to flame and air.
Too small particles are side-ejected upon collosion thus reduces
the particle deposition efficiency.
Pre-exisiting oxidation on particles is not allowed as it reduces
the bond/cohesion strength of coating and is detrimential to other
properties depening on the application, say conductivity, corrosion
resistance.
Hope this help
Hong
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