Nanoporous metallic structures by de-alloying bulk glass forming Zr-based alloys

Nanoporous structures have been produced by selective chemical dissolution of two multicomponent bulk glass-forming alloys with a supposed proper content of the more noble metals - Zr65Ni30Pd5 and Zr55Ni30Al10Pd5. The Al-containing alloy reveals open three-dimensional pores, while the selective dissolution of the Al-free ternary alloy results in larger surface pores and a number of disconnected ligaments. The average width of the ligaments, composed of 3-5 nm nanocrystals, is about 50 nm and the mean pore size for the de-alloyed quaternary alloy is 90 nm. The effect of Al on the ligament morphology and pore size is analyzed.