Metal working – Method of mechanical manufacture – Electrical device making
Patent
1996-04-22
1997-09-30
Bell, Bruce F.
Metal working
Method of mechanical manufacture
Electrical device making
429199, 429225, 429226, 429227, 429228, 205122, 205299, H01M 600
Patent
active
056721811
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/DE 95/00112 filed Jan. 27, 1995.
BACKGROUND OF THE INVENTION
The invention is directed to a method for manufacturing a hardened lead storage battery electrode, finely particulate solids that are insoluble in lead being dispersively distributed in the lead matrix thereof.
Plate grids for lead accumulators are mainly manufactured by gravity casting into moulds by hand or with casting machines and by diecasting with warm chamber or cold chamber diecasting machines. Continuous gravity casting with a drum casting machine and subsequent grid fabrication according to the expanded metal technique is also significant. Punching and stamping of plate grids and build-up welding of pre-fabricated grid parts, for example extruded rods on the basis of gravity casting or diecasting, are less wide-spread. The manufacturing methods respectively comprise specific disadvantages. In gravity casting, the minimum plate thickness is limited to 1 mm and the plate thickness is not constant due, among other things, to irregular erosion of the coating in the casting mold. The diecasting method requires a specific viscosity of the molten metal. For example, lead-antimony alloys having an antimony content of 3 through 8% are therefore not capable of being processed. In continuous gravity casting in a drum casting machine, the minimum plate thickness is limited to approximately 1 mm. The utilization of the raw material is comparatively low in grid manufacture by punching and stamping and the possibilities of grid design are limited. The manufacture of a grid according to the expanded metal technique does not allow a complete optimization of the grid geometry.
Lead alloys are employed as materials for the lead storage battery electrodes since the apparent yield stress (static strength) and the creep resistance (long-time rupture strength) of pure lead are too low.
In order to increase the strength of lead, it is alloyed with elements such as, for example, antimony or calcium and tin, whereby solid solution hardening and dispersion hardening take effect (W. Hofmann, Blei und Bleilegierungen, Springer-Verlag, Berlin/Gottingen/Heidelberg 1962). These alloy elements, however, fundamentally raise the electrical resistance and often have a disadvantageous influence on the electrochemical properties such as the corrosion behavior and the battery behavior due to the formation of gas.
In the light of this background, methods were developed in order to increase the strength of lead storage battery electrodes by dispersion hardening, whereby particles that are insoluble in lead and have a predetermined size and optimally small average spacing must be dispersively integrated into the lead material. Various methods of powder metallurgy have been proposed for producing a lead oxide dispersion in lead in U.S. Pat. No. 3,253,912 and by A. Lloyd, E. R. Newson, "Dispersion strengthened lead: developments and applications in the chemical industry", Proc.Conf.on Lead, 1968, 255-267. A powder metallurgical method for producing an aluminum oxide dispersion in lead was disclosed by M. M. Tilman, R. L. Crosby, D. H. Desy, Dispersion strengthening of lead by coprecipitation, Report BM RI 7570, U.S. Department of the Interior, Washington 1971. These methods, however, all have the disadvantage of non-optimum particle size and dispersion and of comparatively high cost, and also lead to technical problems such as unfavorable electrochemical behavior and lack of weldability. Economical and technical difficulties are thus established in these methods for technical application, for example in batteries.
Fundamentally, thin metal layers with dispersively distributed phases embedded therein can be manufactured by precipitation onto solid bodies from all metals with which an electrodeposition is possible such as, for example, copper, nickel, iron, zinc and lead.
According to the current state of the art, particles of graphite, PTFE, Al.sub.2 O.sub.3, SiC and other substances are introduced into galvanic layers (dispersion coatings) in t
REFERENCES:
patent: 3253912 (1966-05-01), Rooney
patent: 3552000 (1971-01-01), Hirschfeld
patent: 3844910 (1974-10-01), Lipp et al.
patent: 4043878 (1977-08-01), Ehrsam
patent: 4098654 (1978-07-01), Helle et al.
patent: 4235681 (1980-11-01), Shreir
"Bleiakkumulatoren," Varta Batterie AG, pp. 34-35 no month or year available.
"Lead and Lead Alloys, Properties and Technology" Hofmann, pp. 44-51, 74-101 (1970) no month available.
"Strengthening of Electrodeposited Lead and Lead Alloys, I. Process Development," Wiesner et al., Plating, Apr., 1970, pp. 358-361.
"Dispersion Strengthened Lead: Developments and Applications in the Chemical Industry," Lloyd et al., Proc. Conf. on Lead, 1968, pp. 255-267 no month available.
"Dispersion Strengthening of Lead by Coprecipitation," Tilman et al., Report of Investigations 7570, U.S. Dept. of the Interior, Bureau of Mines no year or month available.
"Deposition of Dispersion-Hardened Lead Coatings," Pini et al., Chemical Abstracts, vol. 89, No. 2, Jul., 1978, p. 496.
"Electrodeposition of Dispersion-Hardened Lead Coatings", Pini et al., Chemical Abstracts, vol. 87, No. 1, Sep. 5, 1977, p. 503.
Drefahl Klaus
Olper Marco
Ueberschaer Armin
Warlimont Hans
Bell Bruce F.
Warlimont Hans
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