Synthesis and thermal stability of amorphous Be–B–X alloy coatings

Amorphous Be–B–X alloys are vapor deposited as coatings. The microstructure and hardness of the Be–B–X coatings are examined using transmission electron microscopy and nanoindentation, respectively. Whereas a Be–B-2.5 at.% Cu amorphous coating is found to crystallize to a cubic Be-33 at.% B phase at 673 K, a coating of Be–B-1.8 at.% Fe-0.4 at.% Cr-0.3 at.% Co does not crystallize until at a higher temperature of 748 K. The hardness of the amorphous Be–B–X coating increases with B content but is less than its crystalline counterparts.