FINE-GRAINED METALLIC COATINGS HAVING THE COEFFICIENT OF THERMAL EXPANSION MATCHED TO THE ONE OF THE SUBSTRATE

摘要

Fine-grained (average grain size 1nm to 1,000nm) 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.