high temp during hvof coating

[ehsan]

recently we have one project for WC coating on some thin rings with gas hvof .we get very high temp on part after first pass.ring rotates 200 rpm and we use compressed air for cooling but is not enough.using water is not possible do you have better way for cooloing?

[djewell]

recently we have one project for WC coating on some thin rings with gas hvof .we get very high temp on part after first pass.ring rotates 200 rpm and we use compressed air for cooling but is not enough.using water is not possible do you have better way for cooloing?

Use nitrogen or carbon dioxide. If you drain gaseous nitrogen from a liquid storage tank, it will be extremely cold, so you will not consume a lot.

Alternatively, if you could increase your traverse rate, you would reduce the heat input to the part, lessening the need for cooling. You will have to make more passes to complete the job, but you will be able to keep the part temperature under control.

[Gordon]

Hi ehsan

Agree with djewell.

Speed things up, apply less material per pass.

Apply cooling to where you need it most. A general air blast cooler pointed in the general direction is pretty useless. Get some focussed cooling jets that follow the motion of spray gun and try to remove heat before it has chance to soak into component.

[landemarre]

recently we have one project for WC coating on some thin rings with gas hvof .we get very high temp on part after first pass.ring rotates 200 rpm and we use compressed air for cooling but is not enough.using water is not possible do you have better way for cooloing?

Which gun? JP5000, Wokajet or other HVOF gun or plasma? Which spray distance?

Probably you can try with a higher spray distance, this is generally the best solution.


OL

[wilfred1963]

Yes i agree with Gordan and Djewell speed up your traverse rate if using air to cool you'll most likely need more than your compressor can handle back off on the feed rate may help but time under flame is the critical generally co2 works very well for cooling pending on part configuration and spray parameter I use nitrogen with high pressure air assist, 350 degrees ferinhieght max as general temp. control point. good luck

[jasonpbond]

Agree with all the suggestions above.

If changing feed rate/standoff/parameters is not enough to cool, and you are limited in you availability of compressed air and don't have access to nitrogen or carbon dioxide, I suggest using amplifying air nozzles like the ones at the following link. Provide much higher accuracy of air direction and efficiency of air consumption. Easily positionable for many situations.

https://itwvortec.com/store/1206.html

[Justin]

Agree with the above, too.

You may try to decrease Fuel flow rate if your coating quality allow you to do so.