Dear Fellows:

Anyone can advise how to determine the robotic arm speed on the flat panel without rotation? Currently I am mostly dealing with cylindrical components, thus there is no problem to determine the RPM and transverse speed. However I wish to know what happen to the flat surface with 'step spraying', how should the speed like? How does it correlate to the OEM recommended surface speed, i.e. 75m/min, to achieve the desire coating properties?

Thank You
Ykang

Depends on the Thermal Spray process, the material being sprayed and also the substrate to some extent. In addition to a relevant scan velocity you must also define step up distance (and correct overlapping) to ensure a uniform deposit. Obviously this depends mainly on the material, parameters and the subsequent width of the 'flame' at deposition.

GlenB:

Well, so how would you suggest the scan velocity and step up distance? any particular formulae or guides to follow?

Maybe you could give some simple examples or calculation here...

Thanks

(02-09-2010 01:52 AM)ykang Wrote:  Dear Fellows:

Anyone can advise how to determine the robotic arm speed on the flat panel without rotation? Currently I am mostly dealing with cylindrical components, thus there is no problem to determine the RPM and transverse speed. However I wish to know what happen to the flat surface with 'step spraying', how should the speed like? How does it correlate to the OEM recommended surface speed, i.e. 75m/min, to achieve the desire coating properties?

Thank You
Ykang

Recommended traverse velocity is the same for flat or cylindrical parts. You do not have to calculate your linear velocity from the 75 m/min - that is your velocity. Your robot will probably require you to enter this as mm/sec. 75 m/min is equal to 1250 mm/sec.

The step distance is the same as you use for cylindrical spraying as well. If you calculate your traverse velocity for a cylinder based on 3 mm traverse per revolution, then use the same 3 mm as your step when spraying the flat panel.

I assume that the process is Plasma? Obviously scan speed varies with Thermal Spray processes and substrate materials, geometries, thicknesses, etc. Some Plasma coatings particularly abradables need to be faster than the norm and static substrate cooling is a factor too.

Step up height should be 1/4 to 1/3 of the width of flame at gun to workpiece impact distance. The 1/4 to 1/3 width of 'flame footprint' overlap on subsequent scans will provide a uniform deposit.

Cheers