Wear resistance of nickel and nickel phosphorus alloy electrodeposits

The wear resistance of gray Ni/Cl and Ni/P deposits was evaluated using a crossed-wire test method that stimulates the wear that develops on plug-in type printed wiring boards. All wear samples were lubricated with 2-wt.% five- or six-ring polyphenylether fluid. Some samples plated with a thin layer of cobalt-hardened gold were also examined. Wear test results showed that: (1) gray Ni/P deposits plated from a neutral ammoniacal bath are more wear-resistant for up to 100 wear cycles than nickel deposits plated from an acid chloride bath; (2) hard-gold-flashed Ni/P deposits are more wear-resistant for up to 5000 wear cycles at a 200-g load than hard-gold-flashed nickel deposits plated from an acid chloride bath. A minimum of 5 mu in. hard gold provides this wear protection.<>