Electrodeposited metallic-materials comprising cobalt on ferrous-alloy substrates

An article comprising:

• (i) a substrate material comprising ferrous alloys;
• and
• (ii) an electrodeposited substance forming a metallic layer and/or patch on said substrate material or on an intermediate structure thereon, said metallic layer or patch comprising at least 75% per weight of Co, 0 to 25% per weight of tungsten, 0 to 25% per weight of phosphorus, and 0 to 5% per weight of boron, wherein said metallic layer or patch having a microstructure which is fine-grained with an average grain size between 2 and 5,000 nm and/or amorphous, and said metallic layer or patch exhibiting a tensile or compressive internal stress in the range of between 2.5 and 30 ksi, and having a thickness between 5 micron and 2.5 mm and a porosity in the range of between 0 and 1.5%;
• (iii) wherein said article is with or without said intermediate structure between said substrate material and the electrodeposited metallic layer and/or patch comprising Co, wherein, when present, said intermediate structure comprises Co with a layer thickness of less than 5 microns;
• and
• (iv) wherein said article comprising the substrate material and either the electrodeposited substance, or the electrodeposited substance and the intermediate structure, exhibits a fatigue life cycle number equivalent to or exceeding a fatigue life cycle number of an uncoated substrate material when tested at an applied stress of between ⅓ and ⅔ of the yield strength of said substrate material, wherein said fatigue life cycle number is an axial fatigue cycle number or a rotating beam fatigue cycle number.