Phynox (Elgiloy) is an austenitic cobalt-based alloy (40%Co, 20%Cr, 16%Ni et 7%Mo) strengthened by cold work and capable of additional hardening by aging. Its ultimate tensile strength (UTS) can reach more than 2500 N/mm². Soft annealed temper is achieved by annealing at high temperature (1000-1200°C) followed by rapid cooling. In this temper, its UTS is only approximately 900 N/mm² but the mechanical strength of Phynox increases significantly with cold rolling and its UTS can reach more than 1900 N/mm² only by cold working (rolling). Additional strengthening can be obtained by age hardening at 520°C (3h), for example. The influence of aging is negligible in the annealed condition, but increases significantly with the degree of cold working. Phynox is non-magnetic, extremely resistant to corrosion (not sensitive to corrosion by organic acids), and its behavior in inorganic acids is greatly superior to that of the best stainless steels. Furthermore, Phynox presents an excellent passivity in contact with human tissues (bio-compatibility). Phynox has the ability to be used over a very wide range of temperatures, from 4.2K (liquid helium) to about 500°C. Thanks to its high Young modulus (210kN/mm²), its very high yield strength, (sometimes > 2200 N/mm²), and its good fatigue strength, Phynox has exceptional spring properties. Lamineries MATTHEY SA delivers Phynox strips according the following standards: ASTM F-1058 (surgical implants), ISO 5832/7 (surgical implants), AFNOR NF S 90-403 (surgical implants), AMS 5875, AMS 5876 and NACE MR0175.

Typical uses
Watch industry : springs, wrist-watch strap parts, etc.; Medical : orthodontics, pacemaker electrodes, stents, needles, etc ; Other : weapon parts, spring energized seals, nonmagnetic parts, etc.