Hello,
i want to ask you how can i find:
- solid specific heat
- solid lambda
- melting point
- latent melting heat
for this carbide powder WC10Co4Cr ?

Thank you !
Best regards, Vlad !

Hi again Folks

Would anyone have a copy of the Parts list for a Metco PPGT1-90° arc extension for spraying internal diameters ?

It would be much appreciated

Cheers

Kev

good afternoon guys, My name is Marvin, Im from Nicaragua(Central America) I have been playing with graphite powder. over a shiny surface a well rubbed powder can look like a highly polish metal(shooting for a chrome look but its too dark)

here are a few pics(not plated but just rubbed onto a glossy surface)


so after that, I tried to elctroplate the same plastic spoons with nickel.
the only prep was a spray degreaser and pickling. could not touch the surface too much as the graphite layer is very thin.

now here is the issue. the nickel plated well to the thin graphite surface, but the graphite surface was not sticking to the glossy surface. so you can actually peel the nickel off without much effort


my next step was to try on a rough surface and its actually holding very well, but the nickel does not look shiny as before..




now here is my question and I hope I placed it in the correct subforum.
what can I do to get graphite powder to stick to a glossy surface? maybe a microscopy acid etching?

Thanks
Marvin

I want to spray alum wire with a Metco 12 standard gearing with acet. I am spraying a pipe with a 58" OD that is 10ft long. I estimated the weight of required material to be about 30# if it was done perfect so I doubled the expected usage for error. My partner argues that it will be around 150# to complete the job. I used the Metco book as a guide but may be calculating it wrong. Any suggestions on what the total weight would be?

I want to spray alum wire with a Metco 12 standard gearing with acet. I am spraying a pipe with a 58" OD that is 10ft long. I estimated the weight of required material to be about 30# if it was done perfect so I doubled the expected usage for error. My partner argues that it will be around 150# to complete the job. I used the Metco book as a guide but may be calculating it wrong. Any suggestions on what the total weight would be?

Hi Folks,

I have a request to source a wire for ARC and or Flame Spray, however all I have is the composition

Fe Bal Cr 10% Al 7% Mo 5% Ni 5%

Does anyone recognise this ?

I'd appreciate any help

Muchas Gracias

Kev

Hey all, I'm totally out of my element when it comes to this topic but I recently acquired a few remaining parts after cleaning out my fathers old shop.(which they did plasma work) i believe the parts are all for a 9MB unit and I have a nozzle(9mb-732), what looks to be another nozzle (P7c-b) with 2 o-rings on it, and 63P.

If anyone can help me to the value of these(new in tubes) and if someone would be interested please let me know. They are the last of my liquidation and I'm stumped!

Thanks everyone

Hello All

Again - old subject in the forum but new for me. We are recently working on develop HVOF coating with customer approved powders - Metco 5847 and Praxair WC-731-1. Tensile, bond strength, microstructure and micro hardness required. We couldn't get required min 950HV0,3 hardness with Praxair powder in any configuration, so right we are testing Metco 5847. We get tensile and micro hardness, porosity also good but "clusters" in coating appears, which customer is not happy about. What are those clusters might be and how can we eliminate it from coating.

Thank You very much for help.



Admin Edit - This is a new thread split from http://www.gordonengland.co.uk/sef/Threa...rs-by-HVOF and for continuity a few quotes from earlier posts:

(11-08-2009 05:53 AM)k09 Wrote:  Hi,

I cant use Plasma.. Their product specification clearly specifies HVOF!! So option of using another process is ruled out

My colleagues suggested that the higher hardness range is due to over heating of the sprayed particles. So to counter this i will have reduce the fuel and oxygen input. Am i goin in the right direction here??!

Also, if i am to reduce it...How much shud i reduce it...1-2% or should it be as high as 5-10%

Whatever the case, I have no doubts that i will have to conduct all tests again!

(11-21-2009 04:06 PM)Gordon Wrote:  Hi K09

Quote:My colleagues suggested that the higher hardness range is due to over heating of the sprayed particles.

This is certainly a possibility. Production of metastable phases can harden and make the supporting matrix more brittle. Increased hardness and reduced ductility of the CoCr matrix can show itself sometimes (not always) as a harder coating as a whole, this condition tends to have negative effects on durability and wear resistance of the coating.

Do you have any (other than hardness) indications towards over-heating and production of unwanted phases? Hardness alone is not a good indicator.

Quote:So to counter this i will have reduce the fuel and oxygen input. Am i goin in the right direction here??!

Also, if i am to reduce it...How much shud i reduce it...1-2% or should it be as high as 5-10%

This is difficult to answer, as I don't know your base line conditions. Also, you need to be sure that the higher coating hardness (according to your customer specification) that you are achieving is due to particle over-heating and is not just the natural results of good process/coating.

You could manipulate parameters to give softer coatings and make people happy that specifications are being met, but without knowing exactly what is going on inside the coating, you could end up with poorer coating. Just seems possibly a retrograde step.

(11-24-2009 06:11 AM)k09 Wrote:  Hi Gordon,

Can microstructure images help in making any conclusions in this matter?

I have a report which includes results of Microstructure, Bend test, Bond Strength and Hardness test. All results are positive. The testing facility infact, in a telephone conversation also commented that the coating appeared better than Detonation spray coatings!

If microstructure can help, i will forward you a copy of the image for analysis

(11-25-2009 04:00 PM)Gordon Wrote:  Hi K09

It can be difficult to see the more subtle effects in normal metallography. In more extreme cases, primary WC phases may appear reduced and matrix increased. A very qualitative method I have used is to etch samples with a modified Murakami's reagent (basically a diluted form). The ideal coating, one with no other phases than WC and CoCr matrix will show no or little etching effects. Unwanted phases tend to be vigorously etched. It is not a pretty etch and can spoil samples if you need to archive or process further, so I would advise making a separate specimen/mount for this purpose or at least leaving this test to the very last.

I have Rokide 9800,melted ceramic powders do not stick to material.Very low percentage of melted ceramic powders stick.We applied sand blast just before the coating but again not stick sufficiently, coating thickness not reach to 50 micron.What must we do about this problem?

I am awaiting your answer.

Best Regards

Hi,
im new in plasma spray.
Currently working in a production line doing plasma spray.

Mainly using F4 gun for spraying.
Frequently using among metco 313, 601, 320..... and some hard coatings.

I would like to know is there anyways to improve the depostion buildup per cycle without changing the parameters and feedrate and able to get the required hardness?

Because for production, there will be time reduction every year.

Theres no engineer here to do process improvement, so the only way here is to work faster so that to be able to finish the part in time.

Thanks for reading.
Hope to get some help..... cheers~