TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The electrochemically deposited alloy is iron-indium, tin-zinc (preferred), silver-cobalt, silver-bismuth, silver-iron, silver-nickel, indium-zinc, bismuth-cobalt, bismuth-copper, bismuth-tin, bismuth-zinc, palladium-copper, palladium-cobalt, cobalt-copper, silver-copper, gold-copper or gold-cobalt based-alloys. The binary metallic alloy: under (a) is iron-indium, tin-zinc, silver-cobalt, silver-bismuth, silver-iron, silver-nickel, indium-zinc, bismuth-cobalt, bismuth-copper, bismuth-tin and bismuth-zinc; and under (b) palladium-copper, palladium-cobalt, cobalt-copper, silver-copper, gold-copper and gold-cobalt based-alloys. Preferred Process: The chemical or electrochemical etching is carried out by a solution dissolving the metallic phase, where the solution is a concentrated or diluted inorganic acid, organic acid, inorganic base and/or organic base. The chemical etching of the zinc phase is carried out with diluted hydrochloric acid. The layer of the substrate metal is added on top of the tin-zinc layer prior to etching to obtain a metal tube with a microporous inner structure. The coating or structure, which is an electrodeposited material in the form of a binary metallic alloy contains metals that are essentially insoluble in each other or do not form intermetallic phases at below 200 degrees C. EXAMPLE - A copper substrate was degreased cathodically in an alkaline solution and activated (pickled) in a commercial acidic solution. Then the tin-zinc alloy was electrodeposited on the copper plate at an applied current density of 1 A/dm2 at 40 degrees C in a commercial electrolyte (where the commercial electrolyte was slotoloy zinc-tin (ZSN) 21 (0.6 l/l), FS-20 (0.013 l/l), slotoloy ZSN 22 (0.04 l/l ), slotoloy ZSN 23 ( 0.0015 l/l), zinc chloride (70 g/l), potassium chloride (45 g/l) and boric acid (30 g/l)) for 12 minutes. The zinc content in the deposit was 10-40% depending on the agitation. A selective etching of the zinc in the tin-zinc alloy deposit was carried out at room temperature with diluted hydrochloric acid (1 part concentrated 37% hydrochloric acid and 9 parts distilled water) for 0.5, 1.4 and 24 hours, respectively. The etching time may be accelerated by increasing the acid concentration, by using electrochemical etching, and by increasing the temperature. The number and size of holes in the etched tin-zinc alloy increases with the zinc content. A zinc content of 10% in the alloy deposit was too low for fabricating a porous coating.