Strengthening domains in a Ni–21Cr–17Mo alloy

 The yield strength of a newly developed commercial Ni–21Cr–17Mo (wt.%) alloy (HASTELLOY® C-22HS alloy) can be approximately doubled over a temperature range up to about 600 °C by subjecting the alloy to an age-hardening heat treatment. It is found that the long-range-ordered (LRO) Ni2(Cr, Mo) domains in the age-hardened alloy are responsible for the strengthening. Widespread lamellae of 2–100 nm thickness are observed in samples tensile-tested at both room temperature and 595 °C, and are confirmed to be twins.