Lecture Notes: Industrial Diamond Manufacturing at US Synthetic

Introduction

• Location: US Synthetic, one of the largest industrial diamond manufacturing facilities.
• Focus: Manufacturing genuine Mohs 10 level polycrystalline black diamonds.
• 99% of diamonds used annually are synthetic industrial diamonds.
• Applications include drilling, frictionless bearings, and maintenance-free electricity generation.

Manufacturing Process

Ingredients and Preparations

• Ingredients: Monolithic diamond polishing powder, cobalt from cobalt-cemented tungsten carbide.
• Process:
  • Diamond dust placed in a small metal thimble.
  • Cobalt acts as a substrate for diamond creation.

Creating the Diamonds

• Heater Cylinder:

  • Metal cylinder used to create two diamonds at a time.
  • Filled with clean white table salt to center diamond molds.
  • Salt and talc blocks formed as supports.

• Six-Piston Cubic Diamond Press:

  • Focuses over 1 million PSI onto diamond mold.
  • Press is housed in blast rooms due to high pressure and potential hazards.

Heat and Pressure Application

• Heating Element:
  • Circular positive and negative contact pads heat the metal canister to 2500°F.
  • Heat crystallizes diamond dust and liquifies cobalt.

Formation of Polycrystalline Black Diamonds

• Process:
  • Cobalt leaches into diamond catalyzing crystal formation.
  • Results in tougher synthetic diamonds than natural ones.

Cleanup and Final Steps

• Cleanup:

  • Utilizes non-toxic salt and talc.
  • Uses silicon carbide sandblaster to remove casings.

• Polishing and Uses:

  • CNC polishing machines finish the diamonds to correct dimensions.
  • Tungsten carbide base can be used as a mounting location or removed.
  • Applications include high-end 3D printer nozzles.

Applications and Hardness Testing

• 3D Printing:

  • Diamond 3D printer tips are extraordinarily durable.
  • Resistant to wear from abrasive filaments.

• Hardness Test:

  • Demonstrated using Mohs hardness picks.
  • Polycrystalline diamonds withstand level 9 hardness tests.

Conclusion

• The potential for further uses of diamonds in technology and manufacturing.
• Inquiry into possible future applications, like a diamond phone case.
• Appreciation for the tour and exploration of industrial diamond capabilities.