Ag75W25 INF
Heat-treated state
ASTM B694
INF = tungsten skeleton infiltrated with molten silver
Pick when maximum density, minimum porosity and best arc-erosion consistency are required (heavier-duty switching, oil/SF6 use).
Values for the INF condition
Other Ag75W25 grades and fills
Ag75W25 is listed in 2 conditions; see the grade overview at Ag75W25.
- PSR
- INF
Compare all 2 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
PSRDefault Pressed, sintered and re-pressed | Standard low-cost route for low/medium W contents such as AgW25; balanced conductivity, density ≥98 % theoretical. | 160 | 240 | 8 | — |
INFThis page Tungsten skeleton infiltrated with molten silver | Pick when maximum density, minimum porosity and best arc-erosion consistency are required (heavier-duty switching, oil/SF6 use). | 185 | 270 | 5 | — |
What is Ag75W25 INF?
Ag75W25 INF is Ag75W25 heat treated to INF — pick when maximum density, minimum porosity and best arc-erosion consistency are required (heavier-duty switching, oil/SF6 use). Ag75W25 INF has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 270 MPa (39.2 ksi) — weaker than 58% of composite grades. Elongation at break is 5% and the elastic modulus is 128 GPa (18.6 Msi). Ag75W25 INF has a density of 11.85 g/cm³ (0.428 lb/in³), heavier than 100% of composite grades. PSR is the default condition FabDigit quotes; INF is available on request or by drawing note.
Advantages
- Conducts heat well — 330 W/m·K (190.7 BTU/hr·ft·°F), better than 99% of composite grades
- Good UV / weathering resistance — 100/100, better than 93% of composite grades
- Polishes to a fine finish — 60/100, better than 90% of composite grades
- Ductile — tolerates forming and impact — 5%, better than 86% of composite grades
- High service temperature — 450°C (842 °F), better than 85% of composite grades
Limitations
- Heavy — 11.85 g/cm³ (0.428 lb/in³), worse than 100% of composite grades
- High embodied carbon — 78 kg CO₂/kg, worse than 97% of composite grades
Ag75W25 INF properties
Typical room-temperature values for Ag75W25 INF; 14 are specific to this condition. Other listed values are Ag75W25 reference data and may not represent this condition. Bars are the position among composite grades.
Physical1
Ag75W25 INF has a density of 11.85 g/cm³ (0.428 lb/in³), heavier than 100% of composite grades.
Mechanical11
Ag75W25 INF has a yield strength of 185 MPa (26.8 ksi) and a tensile strength of 270 MPa (39.2 ksi) — weaker than 58% of composite grades. Elongation at break is 5% and the elastic modulus is 128 GPa (18.6 Msi).
Thermal5
Ag75W25 INF is rated for continuous service to 450°C (842 °F). It conducts heat at 330 W/m·K (190.7 BTU/hr·ft·°F), better than 99% of composite grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical1
Ag75W25 INF has an electrical resistivity of 2.15×10⁻⁸ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (72/100), worse than 58% of composite grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of Ag75W25 INF takes about 1,200 MJ of energy and emits 78 kg of CO₂ — more than 97% of composite grades. Typical recycled content is 40%.
Manufacturability2
Ag75W25 INF's machinability is poor (32/100, worse than 51% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Ag75W25 INF
Is Ag75W25 easy to machine?
Machinable with sharp carbide or PCD tooling at moderate speed and generous coolant; the W phase is abrasive and the Ag matrix smears, so grinding/EDM is common for finish faces.
Can Ag75W25 be welded?
Not fusion-weldable as a joint material; tips are resistance-welded or brazed (Ag-Cu-P / Ag-Cu-Zn filler) to copper or brass carriers, ideally via a silver backing layer.
Can Ag75W25 be formed, bent or molded?
Net-shape by die pressing plus sintering (optionally re-pressing or Ag infiltration); only limited hot extrusion/coining, no cold forming of thick sections.
What surface finishes work on Ag75W25?
Contact face is ground/coined and normally left bare; carrier sides may be Ag or Ni plated, and anti-tarnish passivation is used for long-shelf-life parts.
Ag75W25 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Wtungsten phase (skeleton or dispersed particles) | 24 – 26 | 25 |
| Other (total impurities)residual Fe, Ni, Co, O from powders/sintering aids | ≤ 0.2 | — |
| Agsilver matrix, min 99.95 % purity feedstock | ≥ 74 (balance) | — |
Ag75W25 INF — frequently asked
What is Ag75W25 INF used for?
Ag75W25 INF is typically used for relay contacts, circuit breaker contacts and contactor tips. In short: low contact resistance; low-voltage switching grade; silver-cost limited.
What is the yield strength of Ag75W25 INF?
Ag75W25 INF has a typical yield strength of 185 MPa (26.8 ksi) and a tensile strength of 270 MPa (39.2 ksi) — weaker than 58% of composite grades. Strength varies by condition: see the 2 listed tempers.
Is Ag75W25 INF easy to machine?
Not especially — machinability is rated poor (32/100, worse than 51% of composite grades). Machinable with sharp carbide or PCD tooling at moderate speed and generous coolant; the W phase is abrasive and the Ag matrix smears, so grinding/EDM is common for finish faces.
Can Ag75W25 INF be welded?
Not fusion-weldable as a joint material; tips are resistance-welded or brazed (Ag-Cu-P / Ag-Cu-Zn filler) to copper or brass carriers, ideally via a silver backing layer.
What surface finishes work on Ag75W25 INF?
Contact face is ground/coined and normally left bare; carrier sides may be Ag or Ni plated, and anti-tarnish passivation is used for long-shelf-life parts.
Can Ag75W25 INF be formed, bent or molded?
Net-shape by die pressing plus sintering (optionally re-pressing or Ag infiltration); only limited hot extrusion/coining, no cold forming of thick sections.
What is the maximum service temperature of Ag75W25 INF?
Ag75W25 INF is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Ag75W25 PSR and Ag75W25 INF?
PSR is the default condition — standard low-cost route for low/medium W contents such as AgW25; balanced conductivity, density ≥98 % theoretical. INF: pick when maximum density, minimum porosity and best arc-erosion consistency are required (heavier-duty switching, oil/SF6 use). Yield strength is 160 MPa in PSR versus 185 MPa in INF.
Sources
- ASTM B694 — Refractory Metal–Silver Composite Electrical Contact Material — ASTM International (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (electrical contact materials) — ASM International (1990)
- Data Book of Electrical Contacts (AgW contact material sheets) — DODUCO (2012)
- ASM Handbook Vol. 7 — Powder Metallurgy (infiltrated refractory-metal composites) — ASM International (2015)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.