Wear resistance of nickel and nickel phosphorus alloy electrodeposits

The wear resistance of gray Ni(Cl bath) and Ni/P deposits was evaluated using a crosswire test method that simulates 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 nearly pH ammoniacal bath are more wear-resistant for up to 100 wear cycles than nickel deposits plated from an acid chloride bath; and (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 127-nm hard gold provides adequate wear.<>