Electrochemical machining process

face; and a rear face of corrosion­resistant material.

COAnNG PROCISSu.s. Patent 5,879,532. Mar. 9, 1999D. Foster et ai., assignors to MascoCorp. of Indiana, IndianapoLis

A process of depositing a multi­layer coating containing metal ormetal alloy on at least a portion ofan article surface comprising de­positing by electroplating at leastone electroplated metal or metalalloy layer on at least a portion ofthe article surface to form an elec­troplated article; subjecting theelectroplating article to pulseblow drying; and depositing by va­por deposition at least one layerselected from the group consistingof refractory metal and refractory

metal alloy and at least one layerselected from the group consistingof refractory metal compound andrefractory metal alloy compound.

ILECTIIOCIIIMICAL MACHININGPROCISSU.S. Patent 5,879,533. Mar. 9, 1999F.P. WardLe. assignor to SKFIndustriaL Trading & DeveLopmentCo. B. V., Nieuwegein, NetherLands

A method of electrochemicallymachining a metal piece, whereinby applying a voltage a current ispassed across a narrow gapformed by the metal piece and anadjustable electrode means to lo­cally remove material from themetal piece, electrolyte being sup­plied to the gap in a direction sub­stantially tangential to the sur-

face of the metal piece, and themetal piece being rotated aroundits axis, the amount of currentbeing under the control of ameans capable of sensing the sur­face of the metal piece, character­ized in that the metal piece is abearing ring and wherein theelectrochemical local removal ofmaterial from the bearing ring isenhanced by controlling a param­eter chosen from the group ofchanging the speed with whichthe bearing ring is rotated, andincreasing the voltage when thegap is narrow due to a local eleva­tion on the bearing ring.

MRIIOD. acov_...DTIIACTAJITu.s. Patent 5,879,556. Mar. 9. 1999

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