Cobalt Chrome F75


Cobalt Chrome F75

Parts built from CobaltChrome conform to the chemical composition UNS R31538 of high carbon CoCrMo alloy. They are nickel-free (< 0.1 % nickel content) and are characterized by a fine, uniform crystal grain structure. As built CobaltChrome meets the chemical and mechanical specifications of ISO 5832-4 and ASTM F75 for cast CoCrMo implant alloys, as well as the specifications of ISO 5832-12 and ASTM F1537 for wrought CoCrMo implants alloys except remaining elongation.

The remaining elongation can be increased to fulfil even these standards by high temperature stress relieving or hot isostatic pressing (HIP). Parts made from CobaltChrome can be machined, spark-eroded, welded, micro shotpeened, polished and coated if required. They are suitable for biomedical applications and for parts requiring high mechanical properties in elevated temperatures (500 - 1000 °C) and with good corrosion resistance.

Mechanical Properties Test Method As Built Heat Treated
Tensile Strength ISO 6892-1:2009(B) Annex D 1300 ± 100 MPa 1100 ± 100 MPa
Yield Strength (Rp 0.2%) ISO 6892-1:2009(B) Annex D 1000 ± 100 MPa 600 ± 50 MPa
Elongation at Break ISO 6892-1:2009(B) Annex D Approx. 15 ± 4% Approx. 15 ± 4%
Young’s Modulus - 200 ± 20 GPa 200 ± 20 GPa
Hardness DIN EN ISO 6508-1 35 ÷ 40 HRC -
Thermal Properties Test Method As Built Heat Treated
Thermal conductivity ASTM E1461-13 15 ± 3 W/m°C -
Max. Operating Temp. ASTM E1461-13 Approx. 1150°C -
Chemical Composition and Physical Properties    
Chemical composition Co
Cr
Mo
Si
Mn
Fe
C
Ni
60 - 65%
26 - 30%
5 - 7%
≤ 1%
≤ 1%
≤ 0,75%
≤ 0,16%
≤ 0,10%
Physical Properties Relative density Approx. 99,99 %
  Density 8,30 g/cm3
Heat Treatment Temperature Time (h) Atmosphere
Stress Relief RT - 1150°C 3 Inert
  1150°C 6 Inert
  1150°C - RT - Inert