Metallicity of Plasma spray

[plzc126330]

Dear Friends,

I have a question about Plasma spray coating with Metal powder, so after Plasma flame treatment, metal will lose their metallicity, and coating will became brittle, so I want to know what is the mechanism, thanks for all of your comments!

B.R
Z

[demionkrishan]

Dear Friends,

I have a question about Plasma spray coating with Metal powder, so after Plasma flame treatment, metal will lose their metallicity, and coating will became brittle, so I want to know what is the mechanism, thanks for all of your comments!

B.R
Z

Dear,
Can you explain bit deeper? let us know what component, powder, machine,gun are you using, etc....if more heat produce or slow feed/speed rate , bad surface preparation etc then there will be a possibility for brittle.. as my experience so far

Process below..
1.will do the pre heat treatment (HT)/ solution HT to soften the material
2.then will do weld repair if required
3.Post /post and age HT
4.will do masking for the component
5.Surface blast prepartion
6.will check the Roughness( for metalic coating above 200 micro Siemens required)
7.Test specimen for the FPQ
8. proceed coating



Plasma is the term used to describe gas which has been raised to such a high temperature that it ionizes and becomes electrically conductive. In the case of Plasma spraying, the plasma is created by an electric arc burning within the nozzle of a plasma gun and the arc gas is formed into a plasma jet as it emerges from the nozzle. Powder particles are injected into this jet where they soften and then strike the surface at high velocity to produce a strongly adherent coating. The work piece remains cool because the plasma is localized at the gun.

Regards,
D.K.Francis

[loriolo]

Hi B.R
There are a lot of systems in order to apply coatings, as well as there are an unlimited number of coatings materials, to select the correct combination for your applications, and to know if you are doing well, the knowledge of a coating specialist is usually required, and if you have this misdoubts, you can read a lot of technical notes about process and applications in this thermal spray forum, otherwise you could ask about an expert near your facilities, take in main that thermal spray is a process system though which melted or molten spray materials are propelled at very high speed onto a surface to be coated, this cause the particles to deform and spread on the substrate and each other like pancakes, and the particles bond each other and adhesion is based on mechanically hooking with a metallurgical bond and micro welded points, so, not ever the coating became brittle, it depend on the parameters setting, material, and application needed.