Fine-grained (average grain size 1 nm to 1,000 nm) metallic coatings
optionally containing solid particulates dispersed therein are disclosed.
The fine-grained metallic materials are significantly harder and stronger
than conventional coatings of the same chemical composition due to
Hall-Petch strengthening and have low linear coefficients of thermal
expansion (CTEs). The invention provides means for matching the CTE of
the fine-grained metallic coating to the one of the substrate by
adjusting the composition of the alloy and/or by varying the chemistry
and volume fraction of particulates embedded in the coating. The
fine-grained metallic coatings are particularly suited for strong and
lightweight articles, precision molds, sporting goods, automotive parts
and components exposed to thermal cycling. The low CTEs and the ability
to match the CTEs of the fine-grained metallic coatings with the CTEs of
the substrate minimize dimensional changes during thermal cycling and
prevent premature failure.