Electrodeposited coatings for diamond turning applications

Electrodeposited coatings are attractive for precision machining operations because thick coatings can be economically applied, with good adhesion, to a variety of substrates. Approximately 20 pure metals and a large number of alloys can be deposited from aqueous solutions. Fused salt and organic solvent electrolytes can be used to lengthen the list of metals that can be electrodeposited. However, both the choice of the metallic coating and the control of the plating process are critical for success in precision finishing of electrodeposited coatings. Some preliminary results at the National Institute of Standards and Technology and at the Lawrence Livermore National Laboratory suggest that electrodeposited nickel-phosphorus alloys are excellent coatings for single point diamond turning from the standpoint of material properties and low tool wear. Electrodeposited aluminum and aluminum alloy coatings also merit consideration for precision finishing where weight is an important factor. 10 refs., 6 figs