Tungsten electrical contact

copperfor contactorsfor circuit breakers

Product overview
Low‑gas contact materials designed for use in vacuum chambers. Switching contacts in tungsten‑copper (WCu) and tungsten‑carbide‑copper (WCCu) compositions reliably switch high short‑circuit currents in vacuum contactors, closed‑circuit systems and reclosers within the 7.2–24 kV range and are capable of exceeding one million switching cycles.

Key advantages

• High resistance to arc erosion
• Excellent electrical conductivity
• Strong resistance to contact welding
• Very low chopping current

Available materials

• VFG10 — W 90 wt% / Cu 10 wt% (Vacuum Fine Grained, ultrapure)
• VFG20 — W 80 wt% / Cu 20 wt% (Vacuum Fine Grained, ultrapure)
• WCCu30 — WC 70 wt% / Cu 30 wt% (economic alternative for vacuum use)

Manufacturing
Composites are produced by powder metallurgy: mixing of base powders, pressing and sintering. This process achieves high material density (>97%) and the required combination of electrical and mechanical properties.

Typical material properties (summary)
Materials: VFG10, VFG20, WCCu30
WC (wt%): 0, 0, 70
W (wt%): 90, 80, 0
Cu (wt%): 10, 20, 30
Density (g/cm3): 16.5, 15.2, 12.2
Electrical conductivity (m/Ω·mm2): 22, 25, 15
Hardness HV30: 220, 210, 230

Technical specifications

• Materials: tungsten‑copper (WCu) and tungsten‑carbide‑copper (WCCu)
• Application voltage range: 7.2–24 kV (vacuum contactors, closed‑circuit systems, reclosers)
• Cycle durability: >1,000,000 switching cycles (application dependent)
• VFG quality: Vacuum Fine Grained — ultrapure, high conductivity
• Available grades: VFG10 (W90/Cu10), VFG20 (W80/Cu20), WCCu30 (WC70/Cu30)
• Typical densities and conductivities as listed above
• Manufacturing: powder metallurgy (mixing, pressing, sintering) achieving >97% density