Chemical properties and applications of some amorphous alloys

Abstract

Chemical properties of a variety of amorphous alloys prepared by melt spinning and laser processing were studied in relation to their application possibilities. In hot concentrated HCl, HNO 3 and H 3PO 4, NiTa alloys showed the highest corrosion resistance among a number of amorphous nickel-valve metal alloys, forming a passive TaO 2(OH) film. As anode materials for sea-water electrolysis, amorphous NiNb and NiTa alloys with a few at.% platinum-group metals are superior to the PtIr/Ti electrode used currently. Some amorphous alloys for fuel cell electrodes and corrosion resistant amorphous alloys in hot concentrated NaOH are also described. Amorphous NiCrPB surface alloys were successfully prepared on mild steel by laser processing, but the vitrifiable composition range by the laser method was much narrower than that prepared by the melt spinning. Amorphous NiNbPt-group element surface alloys prepared by laser processing showed the same high electrocatalytic activity as those prepared by a conventional method.