Vacuum Brazing PDC to Stainless Steel

Vacuum Brazing PDC to Stainless Steel

Polycrystalline diamond compact (PDC) components are widely used in cutting, drilling, and wear-resistant applications due to their exceptional hardness and durability. In many assemblies, PDC elements must be securely joined to stainless steel parts that provide structural support and corrosion resistance. Vacuum brazing is a preferred joining method, but it requires precise process control due to the unique properties of both materials.

Technical Challenges

1. Thermal sensitivity of PDC: Excessive temperature can cause diamond degradation or graphitization.

2. Thermal expansion mismatch between PDC (tungsten carbide substrate) and stainless steel.

3. Oxide formation on stainless steel, which can inhibit proper wetting.

4. Residual stress management during cooling.

Brazing Alloys and Materials

Low-temperature active brazing alloys, typically silver- or copper-based with titanium additions, are commonly used. Titanium promotes bonding to carbide surfaces without the need for metallization, while the ductility of silver-based fillers helps accommodate thermal stresses. Brazing temperatures are typically maintained between 650 - 750 °C to protect the diamond layer.

Why Vacuum Furnace Brazing

1. Flux-free, oxide-free environment

2. Precise temperature and atmosphere control

3. Uniform heating and controlled cooling

4. Clean, repeatable, and high-strength joints

Our advanced Normantherm vacuum furnaces allow multi-step thermal cycles that protect the PDC while ensuring complete filler flow and joint integrity.

To sum up, brazing PDC to stainless steel is a specialized process that demands careful material selection, joint design, and thermal control. Vacuum furnace brazing provides the precision and cleanliness required to produce strong, reliable joints while preserving the performance of the PDC material. With the right process and equipment, manufacturers can achieve consistent, production-ready results.