Electrodeposited amorphous ductile alloys of nickel and phosphorus

摘要

Smooth, specular, ductile alloys of a transition metal and phosphorus (particularly nickel phosphorus) are produced. The ductility is such that when the alloy is in the form of a foil having a thickness up to or greater than 1 mil (i.e. greater than can be obtained by splat cooling) it can be formed into a complex geometric shape, such as a helix, without cracking, and has a ductility comparable to at least about 5 percent (possibly even over 10 percent) for a 25 micron foil subjected to the ASTM Micrometer Bend Test for Ductility of Electrodeposits. The alloy is deposited on a substrate by electroplating in a bath comprising about 0.5- 1.0 molar nickel, about 1.5-3.0 molar phosphorous acid, about 0.1-0. 6 molar phosphoric acid, and about 0.0-0.6 molar hydrochloric acid, with chloride ion in the amount of at least 1.25M, and greater than twice as much chloride as nickel. While the bath contains significant amounts of hydrochloric acid, in order to maintain nitric acid or warm ferric chloride corrosion resistance of the alloy, the chloride ion is limited to about 2.0 molar.