HVOF coatings on inside diameters down to 8 cm [split]

[SteelDryver]

We can do HVOF coatings on inside diameters down to 8 cm (what is that? 3.2 inches) up to 1.5 meters deep.

Steeldryver

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[Gordon]

Hi SteelDryver

We can do HVOF coatings on inside diameters down to 8 cm (what is that? 3.2 inches) up to 1.5 meters deep. Smile

Are you sure? I would be interested in how this is done. I seriously doubt whether it would be able to apply refractiry ceramic type coating suitable for molten aluminium resistance. I hope I think wrongly

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[SteelDryver]

I know it's difficult to believe. Tell me where or how I could post some infos (pdf or powerpoint). I'd love to show you how we do ID HVOF (and now it gets even more difficult to believe) without overheating the substrate.

regards, Steeldryver

Hi SteelDryver

We can do HVOF coatings on inside diameters down to 8 cm (what is that? 3.2 inches) up to 1.5 meters deep. Smile

Are you sure? I would be interested in how this is done. I seriously doubt whether it would be able to apply refractiry ceramic type coating suitable for molten aluminium resistance. I hope I think wrongly

Admin Edit: Post split from aluminum-liquid to form new thread.

[Gordon]

Hi SteelDryver

I know it's difficult to believe. Tell me where or how I could post some infos (pdf or powerpoint). I'd love to show you how we do ID HVOF (and now it gets even more difficult to believe) without overheating the substrate.

You can make a pdf attachment in your posts (1024 KB max) in the same way as attaching images

Admin Edit: Post split from aluminum-liquid to form new thread.

[SteelDryver]

Hi SteelDryver

I know it's difficult to believe. Tell me where or how I could post some infos (pdf or powerpoint). I'd love to show you how we do ID HVOF (and now it gets even more difficult to believe) without overheating the substrate.

You can make a pdf attachment in your posts (1024 KB max) in the same way as attaching images

Hi Gordon,

attached is a paper in relatively poor english. But it does describe the procedure pretty well. Some bedtime reading.

SteelDryver

  ID CoolFlow.pdf (Size: 138.54 KB / Downloads: 7,264)

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[Gordon]

Hi SteelDryver

Thanks for posting article very interesting. I will take a little more time to digest. I still doubt its use in this particular application, but I think its certainly more than worthy for discussion in a new thread. When I have more time, I will create a new thread containing these recent posts, if you don't mind, so as not to go too off topic here.

Admin Edit: Post split from aluminum-liquid to form new thread.

[Gordon]

Hi SteelDryver

Apart from the potential overheating aspect, my main concern was with the very much shortened stand off/spray distance particularly inside a 8 cm hole, once you have the gun down there it can't leave much room to play with, even with an angled spray stream

[SteelDryver]

Hi SteelDryver

Apart from the potential overheating aspect, my main concern was with the very much shortened stand off/spray distance particularly inside a 8 cm hole, once you have the gun down there it can't leave much room to play with, even with an angled spray stream

Hi Gordon,

your absolutely right! 8 cm is really tight. There are several tricks:
trick 1. low power (less than 20kW)
trick 2. complete combustion within the chamber

tricks 1+2 reduce overheating

trick 3 use very fine powders (2-15 microns)
the small particles accelerate more rapidly in the short distance

I run into this kind of disbelief all the time. How about giving me a fighting chance to prove it?

regards, Steeldryver

[Gordon]

Hi SteelDryver

Hi SteelDryver

Apart from the potential overheating aspect, my main concern was with the very much shortened stand off/spray distance particularly inside a 8 cm hole, once you have the gun down there it can't leave much room to play with, even with an angled spray stream

Hi Gordon,

your absolutely right! 8 cm is really tight. There are several tricks:
trick 1. low power (less than 20kW)
trick 2. complete combustion within the chamber

tricks 1+2 reduce overheating

trick 3 use very fine powders (2-15 microns)
the small particles accelerate more rapidly in the short distance

I run into this kind of disbelief all the time. How about giving me a fighting chance to prove it?

regards, Steeldryver

On the contrary, I do believe you I think it is a really good and useful development. Your tricks 1, 2, & 3 answer my original question very well and make sense. if I was playing devil's advocate, really my disbelief was really concern with spraying oxide ceramic coatings suitable for molten aluminium applications. Standard HVOF has problems enough spraying oxide ceramics (though some do with excellent quality at a cost).

Probably playing devil's advocate again , assuming 80mm bore, would you consider this to be HVOF (velocity wise not equipment)? as spray distance/particle dwell time is so limited and would require some spectacular particle acceleration/heating. Don't get me wrong, I'm being a bit pedantic . I've seen plasma spraying of bores ~ 45 mm with spray distances ~ 10mm, while the coatings seem totally different to standard plasma spray, they none the less proved adequate for the particular task. Though I think your HVOF process will produce very different coatings to standard HVOF in very small bores, for the right application it could fill that gap and be a winner

[Boris Eizner]

PLS look
https://www.youtube.com/watch?v=0pDtWIIJCOM

[Boris Eizner]

Hi SteelDryver

Hi SteelDryver

Apart from the potential overheating aspect, my main concern was with the very much shortened stand off/spray distance particularly inside a 8 cm hole, once you have the gun down there it can't leave much room to play with, even with an angled spray stream

Hi Gordon,

your absolutely right! 8 cm is really tight. There are several tricks:
trick 1. low power (less than 20kW)
trick 2. complete combustion within the chamber

tricks 1+2 reduce overheating

trick 3 use very fine powders (2-15 microns)
the small particles accelerate more rapidly in the short distance

I run into this kind of disbelief all the time. How about giving me a fighting chance to prove it?

regards, Steeldryver

On the contrary, I do believe you I think it is a really good and useful development. Your tricks 1, 2, & 3 answer my original question very well and make sense. if I was playing devil's advocate, really my disbelief was really concern with spraying oxide ceramic coatings suitable for molten aluminium applications. Standard HVOF has problems enough spraying oxide ceramics (though some do with excellent quality at a cost).

Probably playing devil's advocate again , assuming 80mm bore, would you consider this to be HVOF (velocity wise not equipment)? as spray distance/particle dwell time is so limited and would require some spectacular particle acceleration/heating. Don't get me wrong, I'm being a bit pedantic . I've seen plasma spraying of bores ~ 45 mm with spray distances ~ 10mm, while the coatings seem totally different to standard plasma spray, they none the less proved adequate for the particular task. Though I think your HVOF process will produce very different coatings to standard HVOF in very small bores, for the right application it could fill that gap and be a winner

https://www.youtube.com/watch?v=0pDtWIIJCOM

[jack.son]

I believe on high-pressure HVOF designs.