Cobalt-Chrome Alloy F90 · heat-treated state · default condition
Cobalt-Chrome Alloy F90 Solution Annealed
Properties of the Solution Annealed condition, compared with the other F90 tempers.
Standard stocked condition: maximum ductility and corrosion resistance for forming, machining and welding before final processing.
What is F90 Solution Annealed?
F90 Solution Annealed is F90 heat treated to Solution Annealed — standard stocked condition: maximum ductility and corrosion resistance for forming, machining and welding before final processing. F90 Solution Annealed has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 1,000 MPa (145 ksi) — weaker than 93% of cobalt-chrome alloy grades. Elongation at break is 55% and the elastic modulus is 225 GPa (32.6 Msi). F90 Solution Annealed has a density of 9.13 g/cm³ (0.33 lb/in³), heavier than 98% of cobalt-chrome alloy grades. It melts at 1,330°C (2,426 °F).
Advantages
- Tough — resists crack growth — 100 MPa·√m (91 ksi·√in), better than 97% of cobalt-chrome alloy grades
- Ductile — tolerates forming and impact — 55%, better than 96% of cobalt-chrome alloy grades
- High service temperature — 980°C (1,796 °F), better than 93% of cobalt-chrome alloy grades
- Readily welded — 70/100, better than 90% of cobalt-chrome alloy grades
- Forms and bends easily — 55/100, better than 90% of cobalt-chrome alloy grades
Limitations
- Poor heat conductor — 9.6 W/m·K (5.55 BTU/hr·ft·°F), worse than 97% of cobalt-chrome alloy grades
- Low strength — 460 MPa (66.7 ksi), worse than 93% of cobalt-chrome alloy grades
- High embodied carbon — 18 kg CO₂/kg, worse than 90% of cobalt-chrome alloy grades
F90 Solution Annealed properties
Typical room-temperature values for F90 Solution Annealed — 14 properties are specific to this condition; the rest are grade-level values shared by every F90 temper. Each bar shows where the value sits among the cobalt-chrome alloy grades in FabDigit's library — further right is higher.
Physical3
F90 Solution Annealed has a density of 9.13 g/cm³ (0.33 lb/in³), heavier than 98% of cobalt-chrome alloy grades. It melts at 1,330°C (2,426 °F).
Mechanical15
F90 Solution Annealed has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 1,000 MPa (145 ksi) — weaker than 93% of cobalt-chrome alloy grades. Elongation at break is 55% and the elastic modulus is 225 GPa (32.6 Msi).
Thermal6
F90 Solution Annealed is rated for continuous service to 980°C (1,796 °F). It conducts heat at 9.6 W/m·K (5.55 BTU/hr·ft·°F), worse than 97% of cobalt-chrome alloy grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
F90 Solution Annealed conducts electricity at 1.9 % IACS, worse than 54% of cobalt-chrome alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (84/100), better than 72% of cobalt-chrome alloy grades.
Sustainability4
Producing a kilogram of F90 Solution Annealed takes about 250 MJ of energy and emits 18 kg of CO₂ — more than 91% of cobalt-chrome alloy grades. Typical recycled content is 25%.
Manufacturability7
F90 Solution Annealed's machinability is poor (16/100, better than 86% of cobalt-chrome alloy grades); weldability very good (70/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other F90 tempers and conditions
F90 is also supplied in 3 other conditions. The full side-by-side table is on the F90 overview.
- Solution AnnealedDefaultStandard stocked condition: maximum ductility and corrosion resistance for forming, machining and welding before final processing.460 MPa yield · 240 HB
- Cold Worked Hard WireHighest-strength condition for guidewires, springs and fine wire where ductility can be sacrificed.1,650 MPa yield · 51 HRC
- Cold WorkedChoose when higher strength and fatigue capability are needed and the part needs little further forming (bar, strip, springs, stent tubing).1,200 MPa yield · 44 HRC
Working with F90 Solution Annealed
Is F90 easy to machine?
Very difficult: rigid setups, positive-rake carbide or ceramic tools, low speed with heavy feed, flood coolant and no dwelling to avoid rapid work hardening.
Can F90 be welded?
GTAW, plasma, laser and electron-beam welding are used with matched L-605 filler; keep heat input low, no preheat, and solution anneal after welding for best ductility and corrosion resistance.
Can F90 be formed, bent or molded?
Form in the solution-annealed condition with generous radii and high forming loads; work-hardening rate is high so intermediate anneals at 1180–1230 °C are usually needed.
What surface finishes work on F90?
Electropolishing and passivation per ASTM F86 give an implant-quality surface; takes a high mirror polish, and can be PVD coated but not anodized.
F90 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 |
|---|---|---|
| Cr | 19 – 21 | 20 |
| W | 14 – 16 | 15 |
| Ni | 9 – 11 | 10 |
| Fe | ≤ 3 | 1.5 |
| Mn | 1 – 2 | 1.5 |
| C | 0.05 – 0.15 | 0.1 |
| Si | ≤ 0.4 | 0.2 |
| P | ≤ 0.04 | — |
| S | ≤ 0.03 | — |
| Cobalance, nominally ~50 % | balance | — |
F90 Solution Annealed — frequently asked
What is F90 Solution Annealed used for?
F90 Solution Annealed is typically used for vascular stents and guidewires, orthopaedic and spinal implants, dental components, gas turbine combustion chamber parts, high-temperature springs and high-temperature fasteners. In short: wrought biomedical cobalt.
What is the yield strength of F90 Solution Annealed?
F90 Solution Annealed has a typical yield strength of 460 MPa (66.7 ksi) and a tensile strength of 1,000 MPa (145 ksi) — weaker than 93% of cobalt-chrome alloy grades. Strength varies by condition: see the 4 listed tempers.
Is F90 Solution Annealed easy to machine?
Not especially — machinability is rated poor (16/100, better than 86% of cobalt-chrome alloy grades). Very difficult: rigid setups, positive-rake carbide or ceramic tools, low speed with heavy feed, flood coolant and no dwelling to avoid rapid work hardening.
Can F90 Solution Annealed be welded?
Yes — weldability is rated very good (70/100). GTAW, plasma, laser and electron-beam welding are used with matched L-605 filler; keep heat input low, no preheat, and solution anneal after welding for best ductility and corrosion resistance.
What surface finishes work on F90 Solution Annealed?
Electropolishing and passivation per ASTM F86 give an implant-quality surface; takes a high mirror polish, and can be PVD coated but not anodized.
Can F90 Solution Annealed be formed, bent or molded?
Form in the solution-annealed condition with generous radii and high forming loads; work-hardening rate is high so intermediate anneals at 1180–1230 °C are usually needed.
What is the maximum service temperature of F90 Solution Annealed?
F90 Solution Annealed is rated for continuous use to about 980°C (1,796 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in F90 Solution Annealed?
Yes — F90 Solution Annealed is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM F90 — Standard Specification for Wrought Cobalt-20Chromium-15Tungsten-10Nickel Alloy for Surgical Implant Applications — ASTM International (2021)
- HAYNES 25 alloy (L-605) technical data — Haynes International (2020)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- ASTM F86 — Surface Preparation and Marking of Metallic Surgical Implants — ASTM International (2021)
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.