Accession Number : ADD014040

Title :   Electrodeposition without Internal Deposit Stress.

Descriptive Note : Patent, Filed 5 Jan 88, patented 22 Nov 88,

Corporate Author : DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s) : Vaaler, Luther E

Report Date : 22 Nov 1988

Pagination or Media Count : 8

Abstract : An apparatus and method are described for electrodepositing an electroform with near zero internal stress. A voltage controlled power supply supplies current to both a mandrel, upon which a primary electroform is deposited, and to a deformable thin disk substrate, upon which a secondary deposit is formed. A strain gage on the deformable substrate measures any deformation caused by internal stress in the secondary deposit. The strain gage is connected to a strain gage transducer to produce an output signal to a proportional controller. The proportional controller in turn supplies a strain-proportional voltage signal to the power supply. A current mask ensures an even current density over the mandrel. After initially adjusting electroforming bath parameters to provide a zero internal stress in the starting electroform, the output from the strain gage causes proportional changes in the bath current to the mandrel to maintain a constant near zero internal stress in the primary electroform. Patents. (JES)

Descriptors :   *ELECTRODEPOSITION, BATHS, CONTROL, CURRENT DENSITY, DEFORMATION, DEPOSITS, DISKS, ELECTROFORMING, INTERNAL, MASKS, OUTPUT, PARAMETERS, PATENTS, POWER SUPPLIES, SECONDARY, SIGNALS, STARTING, STRAIN GAGES, STRESSES, SUBSTRATES, THINNESS, TRANSDUCERS

Subject Categories : Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE