Application — Electrical Contacts & Cu-W Composites
Tungsten Powder for Electrical Contacts
W metal powder (W ≥ 99.85%, F.S.S.S. 1.5–15 µm, O max. 0.06%) for copper-tungsten contact infiltration, vacuum circuit breakers, automotive relays, EDM electrodes, and radiation shielding. ISO 9001:2015 certified. Certificate of analysis with every shipment.
W powder grades for contact applications
| F.S.S.S. | App. density | Typical application |
|---|---|---|
| 1.5 µm | 2.5 g/cc | Fine Cu-W contacts for miniature relays and connectors requiring maximum conductivity |
| 3.0 µm | 3.5 g/cc | General-purpose Cu-W contacts for vacuum contactors and medium-voltage switchgear |
| 6.0 µm | 4.5 g/cc | High-voltage circuit breaker contacts and arc-resistant Cu-W components |
| 10–15 µm | 5.5–6.2 g/cc | Heavy-duty W-Cu composites and counterweight fillers for dense-alloy applications |
All grades: W min. 99.85%, O max. 0.06%, ASTM B430 / ISO-aligned chemistry. Full ICP impurity table on CoA on request.
Applications we supply
Vacuum circuit breaker contacts
W powder (F.S.S.S. 3–8 µm) infiltrated with copper at 1,200°C produces Cu-W contact pads with arc erosion resistance for medium-voltage (12–40.5 kV) vacuum circuit breakers. Low oxygen content (max. 0.06%) is critical to avoid outgassing under vacuum.
Automotive relays and switches
Fine W powder (F.S.S.S. 1.5–3 µm, W min. 99.85%) for pressed and sintered Cu-W contact rivets used in automotive-grade high-current relays — starter motor, EV battery management, and chassis control relays requiring consistent arc erosion resistance over millions of cycles.
High-voltage SF₆ switchgear contacts
Coarser W powder (F.S.S.S. 6–12 µm) for larger infiltrated Cu-W contact assemblies in 110–550 kV SF₆ gas insulated switchgear, where the contact mass and density are critical to withstand fault-current arc energy without welding.
EDM copper-tungsten electrodes
W powder blended with Cu powder and sintered produces Cu-W EDM electrode material — used in die sinking EDM of hardened tool steels where Cu-W's combination of thermal conductivity and arc erosion resistance provides longer electrode life than pure copper.
Radiation shielding inserts
W metal powder compacted into dense-alloy shielding inserts for medical linear accelerators (LINAC), nuclear gauge holders, and radiation therapy equipment — using the 19.3 g/cm³ density of tungsten as a compact alternative to lead, documented to ASTM B777 specifications.
Counterbalance and inertia weights
Coarser W powder (F.S.S.S. 10–15 µm) mixed with a polymer binder and injection-moulded, or pressed and liquid-phase sintered with Ni-Fe binder, produces tungsten heavy alloy counterweights for aerospace gyroscopes, automotive crankshaft balance, and precision instrument mass elements.
Frequently asked questions
What W purity and F.S.S.S. is required for Cu-W electrical contact infiltration?
For Cu-W contact infiltration, tungsten metal powder is typically specified at W min. 99.85%, oxygen max. 0.06%, and F.S.S.S. in the range of 1.5–8 µm depending on the contact density and porosity required for copper infiltration. Finer grades (1.5–3 µm) give higher tungsten skeleton density and lower Cu content after infiltration; coarser grades allow more copper absorption and better thermal conductivity. Full chemistry table on CoA.
How does oxygen content affect Cu-W contact performance?
Oxygen in W powder exists as surface WO₃ oxide. During hydrogen sintering, this oxide is partially reduced, but residual oxygen at the W particle surfaces inhibits Cu wetting during infiltration, causing porosity in the Cu-W composite. For electrical contact applications, W powder oxygen should be max. 0.05–0.08% for reliable infiltration. Our standard W powder specifies O max. 0.06%.
Can you supply W powder matching ASTM B777 tungsten heavy alloy specifications?
Yes. Jayanth Tungsten's W metal powder covers the grain size and purity ranges specified in ASTM B777 for tungsten heavy alloy classes 1–4 (90–97% W). For ASTM B777 compliance, we document W content, F.S.S.S., apparent density, and key impurities (Fe, Ni, Mo, Cu) on the certificate of analysis. Contact us with your specific class requirement.
What is the minimum order quantity for W powder for electrical contact use?
Minimum order quantity is typically 25 kg for sample/trial orders and 100 kg for commercial orders. For established buyers with standing orders, smaller monthly call-offs can be arranged. WhatsApp us with your F.S.S.S. target, quantity, and destination for a quote.
Request W powder pricing for contacts
Share your F.S.S.S. requirement, quantity, and destination port. Our team responds with pricing, lead time, and a sample CoA on business days.