| 摘要 |
Corrosion and wear resistant metallic compositions containing nickel, cobalt, boron and thallium and articles coated therewith are described. Preferred electroless coatings contain nickel and cobalt in a ratio of about 45:1 to about 4:1 and are deposited as hard, amorphous alloy nodules of high nickel content dispersed or rooted in a sofer alloy of high cobalt content. The coatings are preferably deposited on catalytically active substrates from an electroless coating bath containing nickel ions, cobalt ions, thallium ions, metal ion complexing agents and a borohydride reducing agent at pH about 12 to about 14. With post-coating heat treatment coated surfaces exhibit hardness levels as high as about 1300 Knoop.
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