Poor integrity and oxides in Metco450NS

[DUYGU]

Hi All,

Can anyone please help me with my problem below;

I am trying to have an approved ''Metco450ns BC/Metco101bns TC'' coating for one and a half year. I tried several different parameters, have the system checked and calibrated couple of weeks ago. But no matter what I change or do, coatings are rejected by lab. It was lack of bond and seperation since now but now the problem is told to be the bad integrity.
I use F4MB-XL and the power unit is IPS-1000.
I started with Metco's reference parameters by reducing feedrate to nearly half. Than I tried several parameters and as I saw no improvement on the coating I turned back to Metco's ref. parameters again.
We noticed lots of problems on the lab side as well but now I am confused.
Images that are uploaded to the below location is 450NS that was sprayed on to a stainless stell with 600Amps-55Ar-9,5H2-37gr/min-3,5nlpm-carrier gas-5 bars parallel airejts/75m/min Surf.speed and 4mm step
This coating is told to be cold. Are the white sections inside the coating are they unmelted particles or the particles that are not melted very well or are they the powder particles that are melted very well but solidified before the impact, or splashed and solidified.
Is microstructure on the photo a common 450NS microstructure or a rejectable bad microstructure? I really would like to see a good plasma sprayed NiAl microstructure.
Can anyone please advice for the photos?

Please see the links below for the photos;












Regards,

[KevinS]

One of two issues appear to be your problem. The spray could be going turbulent for some reason (angle, geometry) or you could be picking up bounce back for some reason (angle, geometry, air jet positions)
it does not appear to be a gun problem.

Hi All,

Can anyone please help me with my problem below;

I am trying to have an approved ''Metco450ns BC/Metco101bns TC'' coating for one and a half year. I tried several different parameters, have the system checked and calibrated couple of weeks ago. But no matter what I change or do, coatings are rejected by lab. It was lack of bond and seperation since now but now the problem is told to be the bad integrity.
I use F4MB-XL and the power unit is IPS-1000.
I started with Metco's reference parameters by reducing feedrate to nearly half. Than I tried several parameters and as I saw no improvement on the coating I turned back to Metco's ref. parameters again.
We noticed lots of problems on the lab side as well but now I am confused.
Images that are uploaded to the below location is 450NS that was sprayed on to a stainless stell with 600Amps-55Ar-9,5H2-37gr/min-3,5nlpm-carrier gas-5 bars parallel airejts/75m/min Surf.speed and 4mm step
This coating is told to be cold. Are the white sections inside the coating are they unmelted particles or the particles that are not melted very well or are they the powder particles that are melted very well but solidified before the impact, or splashed and solidified.
Is microstructure on the photo a common 450NS microstructure or a rejectable bad microstructure? I really would like to see a good plasma sprayed NiAl microstructure.
Can anyone please advice for the photos?

Please see the links below for the photos;














Regards,

[Vadim Verlotski]

Hi DUYGU,

It seems to me that your problem is too thick monolayers (one pass is formed overly thick coating). Try to increase the velocity of the part relatively the plasma gun in 2-3 times. I think it will help.

Regards

[Laurent]

Hi DUYGU,

We apply 450NS quite often and use parameters detailed below:
Base metal AMS5510/CR9276

electrode diameter 6mm
injector diameter 1.8mm
600A
tension V 66.5
argon flow (nlpm) 55
hydrogen flow (nlpm) 9.5
gas powder flow 2.5
powder flow (g/min) 50
pressure in bowl (mbar) 267
spray distance (mm) 140
spray moving speed (m/min) 75

check step (mm/s) 8 (in place of 4)

Porosity rate should be < 15%
non melted rate < 5%

Hope it helps

Cheers

[Laurent]

Hi All,

Can anyone please help me with my problem below;

I am trying to have an approved ''Metco450ns BC/Metco101bns TC'' coating for one and a half year. I tried several different parameters, have the system checked and calibrated couple of weeks ago. But no matter what I change or do, coatings are rejected by lab. It was lack of bond and seperation since now but now the problem is told to be the bad integrity.
I use F4MB-XL and the power unit is IPS-1000.
I started with Metco's reference parameters by reducing feedrate to nearly half. Than I tried several parameters and as I saw no improvement on the coating I turned back to Metco's ref. parameters again.
We noticed lots of problems on the lab side as well but now I am confused.
Images that are uploaded to the below location is 450NS that was sprayed on to a stainless stell with 600Amps-55Ar-9,5H2-37gr/min-3,5nlpm-carrier gas-5 bars parallel airejts/75m/min Surf.speed and 4mm step
This coating is told to be cold. Are the white sections inside the coating are they unmelted particles or the particles that are not melted very well or are they the powder particles that are melted very well but solidified before the impact, or splashed and solidified.
Is microstructure on the photo a common 450NS microstructure or a rejectable bad microstructure? I really would like to see a good plasma sprayed NiAl microstructure.
Can anyone please advice for the photos?

Please see the links below for the photos;














Regards,


Hello Duygu,
It seems that photos show porosity as well as unmelted particles.
Most probably why didn't pass the test.
Please review previous post with our own parameters, and let me know if you get it improved.
thanks

[loriolo]

Hi Duygu
If you are assured that you are doing the best and there is not problem with spray system or gun, so I've had problem with littlies holes in gas supply tubes, so there was air in the process gas as dynamic suction from the external air, try to analyze process gas composition, if the gas is Ok, so you must change powder, there are OEM approved equivalents powders, Metco materials are not so reliable, since they fired quite all the expert technicians.

[DUYGU]

Hi All,

Can anyone please help me with my problem below;

I am trying to have an approved ''Metco450ns BC/Metco101bns TC'' coating for one and a half year. I tried several different parameters, have the system checked and calibrated couple of weeks ago. But no matter what I change or do, coatings are rejected by lab. It was lack of bond and seperation since now but now the problem is told to be the bad integrity.
I use F4MB-XL and the power unit is IPS-1000.
I started with Metco's reference parameters by reducing feedrate to nearly half. Than I tried several parameters and as I saw no improvement on the coating I turned back to Metco's ref. parameters again.
We noticed lots of problems on the lab side as well but now I am confused.
Images that are uploaded to the below location is 450NS that was sprayed on to a stainless stell with 600Amps-55Ar-9,5H2-37gr/min-3,5nlpm-carrier gas-5 bars parallel airejts/75m/min Surf.speed and 4mm step
This coating is told to be cold. Are the white sections inside the coating are they unmelted particles or the particles that are not melted very well or are they the powder particles that are melted very well but solidified before the impact, or splashed and solidified.
Is microstructure on the photo a common 450NS microstructure or a rejectable bad microstructure? I really would like to see a good plasma sprayed NiAl microstructure.
Can anyone please advice for the photos?

Please see the links below for the photos;














Regards,


Hello Duygu,
It seems that photos show porosity as well as unmelted particles.
Most probably why didn't pass the test.
Please review previous post with our own parameters, and let me know if you get it improved.
thanks

Hi Laurent,

Thank you very much for the info. Which gun and power supply you do use to spray these parameters? Because the step and the carrier gas flow and the feedrate is different but plasma parameters are the same with mine. And I have around 75 Volts with F4MB-XL when I use your parameters?

Regards,