05-13-2013, 02:28 PM,
(This post was last modified: 05-15-2013, 09:57 PM by Killswitch.)
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Killswitch
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Coating solution needed for slurry pump application
pressure pump cavity
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05-14-2013, 09:17 AM,
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Gordon
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RE: Coating solution needed for slurry pump application
Hi Killswitch
to the Surface Engineering Forum.
Not an easy one
I will have to think on this one, not many options as:
* Polished surface does not aid adhesion of coatings
* No line of sight process required
* Cold process required
* Coating system that does not reduce fatigue strength
* Erosion and acidic corrosion resistant
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05-14-2013, 01:57 PM,
(This post was last modified: 05-15-2013, 09:58 PM by Killswitch.)
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Killswitch
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RE: Coating solution needed for slurry pump application
Hi Gordon thanks for taking a look at this for me.
* Polished surface does not aid adhesion of coatings * I may be able to allow the surface to not be polished prior to coating. I am considering doing a shot peening prior. Would this aid in creating a suitiple substrate profile for adhesion?
* No line of sight process required.
* Cold process required * Plasma or HVOF are considered cold processes correct?
* Coating system that does not reduce fatigue strength * This is one of the most crtical pieces of the puzzel. Whatever coating we do we want it to be neautral if not enhance fatigue life. Really we are trying to combat corrosion pitting/ erosion which negtaivly effects fatigue life.
* Erosion and acidic corrosion resistant Would a tugsten carbide coating or perhaps a Inconel based coating work well?
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05-14-2013, 05:05 PM,
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Gordon
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RE: Coating solution needed for slurry pump application
Hi Killswitch
Quote:* Polished surface does not aid adhesion of coatings * I may be able to allow the surface to not be polished prior to coating. I am considering doing a shot peening prior. Would this aid in creating a suitiple substrate profile for adhesion?
Shot peening would be better than polished, but much poorer than grit blasting. Maybe compromise and do both, a heavy peen followed by light grit blasting.
Internal bore surfaces are the worst situation for most thermal spray coatings, as most coatings shrink during application causing tensile stresses and hence try to pull away. Some HVOF/HVAF coatings can be applied with neutral or compressive stresses, but I doubt they could be applied in this situation due to lack of space needed for acceleration the particles.
Quote:* No line of sight process required. * I have been considering Plasma Transfered Wire Arc process or some of these http://www.spraywerx.com/applications/id-applications/
If the parts are to big to rotate fast, then a rotating spray head would be good. Alternatively the gun would have to be traversed in and out while indexing part or gun. Plasma spraying powders would give access to more choice in materials.
Quote:* Cold process required * Plasma or HVOF are considered cold processes correct?
Yes
Quote:* Coating system that does not reduce fatigue strength * This is one of the most crtical pieces of the puzzel. Whatever coating we do we want it to be neautral if not enhance fatigue life. Really we are trying to combat corrosion pitting/ erosion which negtaivly effects fatigue life.
I think a coating system probably at best will enhance fatigue life only from the aspect of reducing wear and corrosion.
Quote:* Erosion and acidic corrosion resistant Would a tugsten carbide coating or perhaps a Inconel based coating work well?
Possibly a WC/CoCr coating.
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05-14-2013, 05:59 PM,
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Arkzik
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RE: Coating solution needed for slurry pump application
Hello,
Your problems sounds pretty tough
* Using Laser Cladding you wount have any adhesion problems and it can be done on on the smooth surface. But you will still have HAZ...
* I have now one project running on the slurry-erosion testings. From tribological point of view WC-Co-Cr and Cr3C2-NiCr HVOF coatings could be considered. However not sure, if you will be able to achieve high coatings density with PTWA and thats could be critical against corrosion.
* Plasma is certainly not a cold process.
Found this video. Maybe it could be useful: https://www.youtube.com/watch?v=CWkOxkFxvnA
Regards,
Arkadi
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05-14-2013, 06:10 PM,
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Killswitch
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RE: Coating solution needed for slurry pump application
The more i read into this the more it seems that any kind of flame spray coating on the internals will flake/ crack or peel off he surface with the expansion contraction of the cylinder bore and due to the high stresses.
Waht about doing a spray and fuse process to acheive a metlergical bond versus a mechanical bond?
is this feasible and what would be required ?
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05-15-2013, 08:52 AM,
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Gordon
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RE: Coating solution needed for slurry pump application
Hi Killswitch
Spray and fused coatings will be strong and metallurgically bonded, BUT is not a cold process and will change substrate properties.
Quote:* Plasma is certainly not a cold process.
Normal plasma spray is a cold process with respect to substrate. PTA plasma transferred arc though is a hot process.
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05-29-2013, 03:10 PM,
(This post was last modified: 05-29-2013, 03:15 PM by eco prokol.)
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eco prokol
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RE: Coating solution needed for slurry pump application
Hi Killswitch
I feel we may be able to help you with a solution and have checked with our technical director. We are Eco Prokol Consultants and Manufacturers
of Advanced Coatings Systems.
Having checked your requirements in the above posts we have a solution that meets them. My email is richardwalker@ecomaintenanceltd.com
Description
The Only Manufacturer and Consultant in the World for CE Certified Pure Polyurea 8 Second Cure Seamless Waterproof Liquid Coatings. Specified by Leading Architects and Blue Chip Companies. Approved Applicator and Installer Network Globally. Products Manufactured Using Green Chemistry
ISO 9001 14001
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02-19-2015, 02:57 AM,
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Axis Machine
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RE: Coating solution needed for slurry pump application
I just joined this forum, mainly to answer a few questions I found while doing a Google search.
My name is Boris Volkov an I am one of the owners with Axis Machine in Baltimore Maryland U.S.A.
Chrome plating is what a lot of people ask for an we are happy to do it. It doesn't last too long and it brings a lot of repeat business.
I usually try to sway people over to electroless nickel plating, when baked on immediately after plating, will give a lot tougher surface then chrome plating and is harder, lasts loner and can be polished to a mirror finish after plating.
Another option is boring it oversize, pressing in a sleeve that's been shrunk in liquid nitrogen, then pinning it in place and welding. This can be done in a wide variety of materials from fully heat treated and through hardened D2 or bimetallics ranging from colmonoy, hastalloy, etc.
The ID can be honed or ID ground, then apply e nickel to build up and then hone to size and polish to a mirror finish.
If you have any questions you can email me at Axisballscrew@gmail.com
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