Tungsten carbide cobalt (WC-Co) is a composite material made by combining hard tungsten carbide particles with a tough cobalt metal binder. This powerful combination delivers exceptional hardness, wear resistance, and toughness, making it a go-to material for cutting tools, dies, and wear parts. Here’s how it’s made:

1. Raw Material Preparation
– Tungsten carbide powder (WC) is the primary hard phase.
– Cobalt powder (Co) is used as the metallic binder.
– Additives or lubricants may be mixed in to aid processing and improve uniformity.

2. Powder Mixing (Ball Milling)
The WC and Co powders are thoroughly blended in a ball mill with a liquid medium (often ethanol or water) and milling media (like steel or tungsten carbide balls). This step:
– Ensures uniform distribution of cobalt.
– Reduces particle size for better packing and density control.
– May take hours or even days depending on the batch.

3. Spray Drying
After mixing, the slurry is dried using a spray dryer, turning the mix into a free-flowing granulated powder. This improves the consistency of compaction and pressing.

4. Compaction (Pressing
The powder is compacted into shape using:
– Uniaxial pressing for simple shapes, or
– Cold isostatic pressing (CIP) for uniform density in complex geometries.

This creates a “green compact” – a soft, shaped form that is ready for sintering.

5. Sintering
The green compact is heated in a vacuum or hydrogen atmosphere furnace at temperatures around 1350–1500°C. During sintering:
– Cobalt melts and liquid-phase sintering occurs.
– WC particles bond together through the cobalt binder.
– The part densifies, shrinking by ~20%, and forms a strong, solid mass.

6. Post-Processing (Optional)
Depending on the final application, the sintered parts may undergo:
– Grinding or lapping for dimensional precision.
– Surface treatments like coating (TiN, TiAlN) for tool performance.
– Quality control through hardness, toughness, and microstructure tests.

Final Product: A Tough, Hard Performer
The end result is a high-performance material with:
– Extreme wear resistance
– Excellent hardness (~1600–2000 HV)
– Reliable toughness from the cobalt binder

This process is a blend of materials science and precision engineering, making WC-Co one of the most valuable materials across industries like mining, metalworking, oil & gas, and aerospace.