Nanoporous surface modification of 316L support materials by electrochemical dealloying

The current study involves electroplating and dealloying processes applied sequentially to form a nanoporous Ni layer on 316L support material to produce a suitable substrate that enables thin film (< 1 mu m) deposition. In this respect, 316L foil was used as a model system to determine the application parameters for the formation of a nanoporous Ni surface layer on porous stainless steel. 316L foils were first electroplated using plating solutions with various Ni:Cu concentrations to yield NixCu1-x alloys with different compositions. The alloys were then subjected to the electrochemical dealloying process in order to dissolve Cu in the alloys back into the plating solutions and to leave a nano-porous Ni surface layer on the 316L surfaces. In the study, NixCu1-x alloys with the Cu content ranging between 10%-70% were evaluated in order to determine an alloy composition offering pore size less than 100 nm upon selective dealloying process. The study revealed that dealloying performed on Ni50Cu50 alloy yields the formation of open pores smaller than 100 nm without any sign of exfoliation.