×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

THERMAL SPRAY

THERMAL SPRAY

THERMAL SPRAY

(OP)
Hi Everybody,

We have just purchased a new Thermal Spray, Brand: Sulzer Metco; Type/Model: 1016/PPC. At present we are in the process of studying the application/operation and we are encountering problems on poor addhesion of coating materials to the work piece especially at edge portions. Anybody has experience on said equipment? BTW, we are in the Philippines and we bought the equipment from Singapore.

RE: THERMAL SPRAY

Mabuhay!  Have you gone back to your equipment supplier for technical assistance?  Only 3 things come to mind with poor adhesion.  Preparation, temperature, and powder/substrate compatibility.  Good luck.

RE: THERMAL SPRAY

bicolexpress,

One more parameter that I would suugest along with those from ornerynorsk.  The orientation or position of the work piece will affect the results.

Think of it as welding.  Overhead welding positions are difficult. Flat horizontal position is easy.  Vertical side position is not as easy.  If the work piece is flat, then the edges are vertical, and need to be rotated to flat position to get same results as flat surfaces.   

RE: THERMAL SPRAY

I suggest that surface preparation is the single biggest variable to be controlled.

The part MUST be absolutely taken to base material, and often a sandblast to roughen the surface is necessary.  

Additionally, the duration in which to spray parts after surface preparation should be kept to a minimum.

RE: THERMAL SPRAY

(OP)
Hi Everybody,

Thank you for all the replies. All your suggestions were noted and will be considered in our study. As to the suggestion of my townmate, ornerynorsk, we have a close coordination/contact with the manufacturer and we have followed all their suggestions and inructions but still we were not able to attain good results. We already tried to focus on work piece surface preparation by sandblasting but the coating also cheaped off when subjected to heat. Our plan now is to apply the "shotgun method", i.e., provide a nos of surfaces in one plate with diff roughness using EDM and apply the spray. Which ever surface got the good adhesion might be the best surface finish suitable to this application.

RE: THERMAL SPRAY

It all really depends on what you're trying to achieve.  It could be that your spray material has a mis-matched thermal conductivity for your substrate.  To help conquer this, you could try to incorporate more porosity in your coating, some microcracks that will absorb the differences in thermal expansion coefficient.  Is this metallic, ceramic or a plastic coating?  The surface preparation, is important. I recommend 60-80 grit blast.  Your spray distance is also very important.  If you're to far away, your coating material will begin rehardening before hitting the surface.  If too close, you could either spray too dense of a coating or even overheat or melt your part.

Aaron A. Spearin
ASQ CSSBB
www.Engineering6ss.com

"The only constant in life is change." -Bruce Lee

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources