Thin film selection for Diamond/Nickel interface

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SUMMARY

The discussion focuses on selecting a thin film for a Diamond/Nickel interface that adheres strongly without interdiffusion and maintains thermal conductivity at temperatures up to 700K. Recommended thin film structures include Ti/Pt/Au, where titanium reacts with diamond, platinum acts as an interdiffusion barrier, and gold bonds well with solder. Alternatives such as chromium and active brazing alloys containing titanium are also considered, with emphasis on sputtering as a preferred deposition method due to its effectiveness in low oxygen environments.

PREREQUISITES
  • Understanding of thin film deposition methods such as sputtering and CVD.
  • Knowledge of material properties, specifically diamond and nickel alloy bonding characteristics.
  • Familiarity with thermal conductivity requirements in high-temperature applications.
  • Basic principles of interdiffusion and adhesion in material science.
NEXT STEPS
  • Research the properties and applications of Ti/Pt/Au thin film structures in high-temperature environments.
  • Investigate the use of chromium as a bonding layer in diamond and nickel interfaces.
  • Explore active brazing alloys and their thermal performance for diamond bonding.
  • Learn about the impact of background pressure on sputtering processes for reactive materials like titanium.
USEFUL FOR

Material scientists, engineers working with diamond and nickel interfaces, and professionals involved in high-temperature applications requiring strong adhesion and thermal conductivity.

toasty1231
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Hello everyone. My task is to select a thin film and deposition method that will achieve a few goals.
The thin film will be sandwitched between a diamond and nickel alloy. The thin film needs to:

  • Adhere to a diamond and nickel alloy strongly without inter diffusion.
  • Stay together up temperatures of 700K, and be decently thermally conductive.

The film can be deposited via standard methods like sputtering, Evaporation, JDC, CVD, ect...

I know that diamond and nickel have similar bond structures (sp3) and a thin film with a similar structure would help maintain a strong bond.

Any info would be greatly appreciated!
 
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Typical film structure put down on diamond to enable solder attachment is Ti/Pt/Au. The Ti reactively bonds with the diamond surface, the Pt prevents inter diffusion, and the Au makes a good bond with solder.

There's some work with Cr as the first layer on diamond. It forms a carbide, so adheres to diamond. Don't know how it would stick to nickel, nor do I know about its inter diffusion barrier properties.

Most of the diamond adhesion systems I worked with were put on by sputtering. You have to have a good (low oxygen background pressure) sputtering system to successfully deposit Ti because it's very reactive and forms a super stable oxide if you have any background oxygen in the chamber.

An alternative might be active brazing alloys, which contain a little bit of Ti that combines with diamond and whatever else you're bonding to the diamond when the braze melts. I used some products from S-bond to attach copper microprocessor heat spreaders to CVD diamond plates and it worked reasonably well. I think there are active braze alloys that might make your 700°C requirement, but I'm not sure. I used the S-bond material because it was easier than waiting through the out of house sputtering service turnaround.

It probably doesn't help with adhesion that diamond and Ni have similar crystal systems. Ni doesn't form a carbide under normal conditions. Diamond abrasive makers sell Ni-coated diamond abrasives, so clearly they can stick Ni to diamond very well. They use fluidized-bed deposition, but I have no idea what the interface chemistry is.
 
hha
 

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I can't express any opinion! Thank you for the topic, I need the same answer!
 
Chromium is the first thing that comes to mind. It bonds strongly to to nickel and nickel is often used as a substrate for chrome surface treatments.
 
graphite?
 

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