Electrodeposition of Alloys. Principles and Practice

660 Pages·1963·9.71 MB·English

by  Abner Brenner (Auth.)

Electrodeposition
of Alloys
PRINCIPLES and PRACTICE
VOLUME I: General Survey, Principles,
and Alloys of Copper
and of Silver
VOLUME II: Practical
and Specific Information
Electrodeposition
of Alloys
PRINCIPLES and PRACTICE
Abner Brenner
National Bureau of Standards
Washington, D.C.
Volume II
1963
ACADEMIC PRESS · New York and London
COPYRIGHT © 1963, BY ACADEMIC PRESS INC.
ALL RIGHTS RESERVED.
NO PART OF THIS BOOK MAY BE REPRODUCED IN ANY FORM,
BY PHOTOSTAT, MICROFILM, OR ANY OTHER MEANS, WITHOUT
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PRINTED IN THE UNITED STATES OF AMERICA
To my dear wife, Sonia, who furnished
incentive and encouragement
and
To my sons: David, Douglas, Michael, and Alan
Preface
In technical literature there is no book which comprehensively covers the
subject of the electrodeposition of alloys. As a matter of fact, except for a small
booklet entitled "Die elektrolytische Darstellung von Legierungen aus
wässerigen Lösungen*' which was written by Robert Kremann almost 50 years
ago, no book dealing exclusively with alloy plating has ever appeared. When
Kremann's book was published in 1914, all the information available on alloy
plating could be treated in 70 pages, but since then the subject has expanded
greatly. The information lies widely scattered in many publications and has
never been collected, organized, and evaluated. This situation makes it difficult
for technical workers to appreciate and utilize the large amount of work that has
been done in the field.
Although several excellent reviews on alloy plating with extensive biblio-
graphies have appeared in recent years, they neither adequately indicate the full
scope of the field nor present a systematic, critical discussion of the theory of
alloy plating. They are mainly of value for calling attention to some of the more
important alloy plating processes. Textbooks on electrochemistry dismiss the
subject of alloy plating with only a few pages of discussion and yet elaborate
on some comparatively unimportant static phenomena of electrochemistry. Even
books on electrodeposition do not adequately discuss the electrodeposition of
alloys. After a brief treatment of principles, a few of the commonly plated alloys
are discussed and the impression is left that the field has been rather un-
cultivated. The presentation of the theory of alloy deposition in the various
textbooks has not changed or improved appreciably since the work of Kremann.
Some of the treatments are actually erroneous, because they deal with non-
existent systems and are thus led toward false conclusions.
The author has attempted to eliminate this hiatus in the field of electro-
deposition. The objective was to produce a textbook, as well as a monograph,
which would serve two purposes: (1) Supply the practical plater with sufficient
information for preparing and operating alloy plating baths so that recourse to
the original literature would not be necessary. (2) Provide the electrochemist,
the researcher, and the student with a scientific presentation of the facts and
theory of alloy plating. A minor objective was to discuss certain topics that are
not adequately treated in existing textbooks. Because of this lack, these topics
are treated at more length than might appear necessary for the subject of alloy
deposition alone.
When the author began the preparation of the treatise in 1947, he estimated
that it would take about 18 months and the book would amount to about
150 pages. However, both of his estimates turned out to be off by a factor of 10.
Because the treatise includes the general, theoretical, and practicable aspects of
vii
viii
PREFACE
alloy deposition, it would have been too bulky as a single volume. Therefore,
the 42 chapters were equally divided between two volumes. The first one covers
the general and theoretical topics and the detailed treatment of the electro-
deposition of alloys containing silver and/or copper. The second volume
contains the detailed treatment of the deposition of the remaining alloys.
This treatise does not include a discussion of the electrodeposition of alloys
from fused salt baths or the formation of alloy coatings by thermally diffusing
separately deposited coatings. Neither are the subjects of black nickel plating
or electroless plating covered. To have included all these topics would have
expanded the text which was already too voluminous.
The literature of alloy plating has been covered through 1959 and most of
1960.
The author has attempted to make this treatise more than a compilation or a
compendium of all published work on the electrodeposition of alloys. He has
attempted to establish a philosophy of alloy plating and to this end has in-
corporated the following treatments. The alloy plating systems have been
grouped into five types, and these have been individually discussed with respect
to the plating variables. The fundamental bases of alloy deposition have been
summed up in six principles. The role of diffusion in alloy deposition, which
previously had been only qualitatively treated, has been thoroughly explored.
The role of the current density versus potential relations in alloy deposition has
been examined objectively, and certain misconceptions regarding their value in
alloy deposition have been pointed out.
The writing of this treatise has been less rewarding to the author than if the
time had been spent on technical reading in more widely diversified fields.
However, the author has obtained one satisfaction. This comes from presenting
to reviewers and critics a document too massive to undergo the customary
dotting of I's and crossing of T's.
December, 1962 A. BRENNER
Acknowledgments
The author, not wishing to burden any one person with the onerous task
of reviewing the manuscript, submitted one or two chapters to each of a number
of scientists who were familiar with the subjects discussed. The names of these
reviewers are listed below, and the author wishes to thank them for their
cooperation. In particular, the author wishes to acknowledge the assistance of
his secretary, Mrs. Anna Chapman, for her neat and accurate typing of the
bulky manuscript with its many tables and legends.
JOHN G. BEACH, Battelle Memorial Institute, VERNON A. LAMB, National Bureau of
Columbus, Ohio. Standards, Washington, D.C.
JOHN A. BENNETT, National Bureau of FREDERICK A. LOWENHEIM, Metal and
Standards, Washington, D.C. Thermit Corp., Rahway, N.J.
LEE O. CASE, University of Michigan, Ann FRANK C. MATHERS, Indiana University,
Arbor, Mich. Bloomington, Ind.
MYRON CERESA, Westinghouse Electric ABRAHAM M. MAX, RCA, Record Div.,
Corp., E. Pittsburgh, Pa. Indianapolis, Ind.
ΒÅÍÍÉÅ COHEN, Wright Air Development FIELDING OGBURN, National Bureau of
Div., Wright-Patterson Air Force Base, Standards, Washington, D.C.
Ohio. EDWARD A. PARKER, Technic, Inc., Pro-
DWIGHT E. COUCH, National Bureau of vidence, R.I.
Standards, Washington, D.C. DAVID SCHLAIN, U.S. Bureau of Mines,
A. H, DUROSE, Harshaw Chemical Co., College Park, Md.
Cleveland, Ohio. SEYMOUR SENDEROFF, Union Carbide Corp.,
CHARLES L. FAUST, Battelle Memorial Inst., Perma Research Center, Cleveland, Ohio.
Columbus, Ohio. JOSEPH M. SHERFEY, National Bureau of
D. GARDINER FOULKE, Sel-Rex Corp., Standards, Washington, D.C.
Nutley, N. J. JOHN L. SLIGH, Jr., National Bureau of
A. KENNETH GRAHAM, Graham, Savage Standards, Washington, D.C.
and Associates, Jenkinstown, Pa. JOHN K. TAYLOR, National Bureau of
SAMUEL HEIMAN, Philadelphia Rust-Proof Standards, Washington, D.C.
Co., Philadelphia, Pa. DENNIS R. TURNER, Bell Telephone Labs.,
LESLIE M. HOLT, University of Wisconsin, Murray Hill, N.J.
Madison, Wis. HERBERT C VACHER, National Bureau of
NELSON W. HOVEY, University of Toledo, Standards, Washington, D.C.
Toledo, Ohio. CHRISTIAN J. WERNLUND, formerly with
GARBIS H. KEULEGAN, National Bureau of Ε. I. duPont de Nemour & Co., now
Standards, Washington, D.C. retired.
ALBERTINE KROHN, University of Toledo, IRVING W. WOLF, General Electric Co.,
Toledo, Ohio. Syracuse, N.Y.
JOSEPH B. KUSHNER, Evansville College, GWENDOLYN B. WOOD, National Bureau of
Evansville, Ind. Standards, Washington, D.C.
ROGER J. LABRIE, National Bureau of VICTOR ZENTNER, Hughes Aircraft Co.,
Standards, Washington, D.C. Los Angeles, Calif.
ix
Contents of Volume I
Part I
GENERAL AND PRACTICAL
1. Survey of Alloy Plating
2. History and Literature of the Electrodeposition of Alloys
3. Conductors, Current Flow, Electrode Potentials, and Definitions
4. Practical Considerations Involved in the Electrodeposition of Alloys
5. Variation in the Composition of Electrodeposited Alloys with the Composi-
tion of the Bath
6. Effect of Operating Variables on the Composition of Electrodeposited Alloys
7. Structure of Electrodeposited Alloys
8. Properties of Electrodeposited Alloys
Part II
THEORY
9. Theory of Electrodeposition of Alloys. General Considerations and Literature
10. The Cathode Diffusion Layer and Its Role in the Electrodeposition of a
Single Metal
11. The Role of the Cathode Diffusion Layer in the Electrodeposition of Alloys
12. Role of Cathode Potentials in the Electrodeposition of Alloys
13. Some Theoretical Aspects of Complexing Agents and Addition Agents
in Alloy Plating
Part III
PRACTICAL CONSIDERATIONS AND SPECIFIC INFORMATION
ON THE ELECTRODEPOSITION OF ALLOYS
ALLOY GROUP A. SOME IMPORTANT ALLOYS OF COPPER AND
SILVER
14. Electrodeposition of Brass
15. Electrodeposition of Copper-Tin Alloys
16. Electrodeposition of Cadmium-Copper Alloys
17. Electrodeposition of Alloys Containing Copper and the Metals of the Iron
Group
18. Electrodeposition of Brass- or Bronzelike Ternary Alloys
19. Electrodeposition of Copper-Silver Alloys and Some Miscellaneous Alloys
of Silver
20. Electrodeposition of Copper-Lead and Silver-Lead Alloys
21. Electrodeposition of Silver-Cadmium and Silver-Zinc Alloys
AUTHOR INDEX SUBJECT INDEX
xix
Part III
(CONTINUED)
PRACTICAL CONSIDERATIONS
and
SPECIFIC INFORMATION
on the
ELECTRODEPOSITION
of
ALLOYS
THE REMAINDER OF this treatise deals with the practical aspects of the electrode-
position of alloys. However, frequent reference is made to the theoretical
concepts treated in Parts I and II. This treatise covers only the electrodeposition
of alloys from aqueous solutions. The electrodeposition of alloys from fused
salt baths and from organic solutions is not included, nor is the production of
alloys by the thermal interdiifusion of two separately deposited metallic coatings.
Some borderline subjects, such as the deposition of black nickel and the deposi-
tion of electroless nickel, are not included.
The grouping of the alloys into chapters for the purpose of discussion and
the order of treatment has been governed more by expediency and convenience
rather than by a set rule. For example, lead-tin and tin-zinc plating are treated
first and in separate chapters, since they are among the most important alloy
plating processes. The various alloys could not be conveniently grouped into
the five different classes of alloy plating systems, since a given alloy might be
depositable from more than one type of plating system; for example, tin-zinc
can be deposited from both regular and irregular alloy plating systems. Most
alloys are grouped together under the heading of that parent metal which was
the most difficult to deposit, since the difficulties associated with the deposition
of this parent metal usually was the overriding consideration in the deposition
of the alloys; for example, all manganese alloys are discussed in one chapter.
Little information is given on the analyses of baths or alloys, and the chemistry
of the complex ions in the plating baths has not been treated at any length,
because this information is available in textbooks on electrodeposition. Short
literature surveys are given for those alloys which are of special importance and
for which the literature is so large that the most important contributions are
difficult to discern.
ALLOY GROUP Β. Mutual Alloys of Cadmium, Lead,
Tin, and Zinc
This group of metals possesses the common characteristic of being depositable from
acid solution with high cathode current efficiency, in some instances 100% efficiency,
although they are less noble than hydrogen. This is because they have in common a high
hydrogen overvoltage. In acid solution the electrode potentials of cadmium, lead, and tin
are close enough together to permit the deposition of mutual binary alloys. Alloys of zinc
with these three metals can also be deposited from acid solution, but less satisfactorily.
Their standard electrode potentials in volts are: Lead, — 0.126; tin (stannous), — 0.136;
cadmium, — 0.403; and zinc, — 0.763. In alkaline solutions the static potentials of the
metals are closer together.
The four metals also have the common characteristic that they serve as good protective
coatings for steel. Of these, cadmium and zinc protect by their sacrificial galvanic action.
In corrosive environments lead and tin may sometimes be anodic (less noble) sometimes
cathodic (more noble) with respect to steel.
Because of the similarities in the methods of deposition and in the uses of the binary
alloys of these four metals, it is convenient to treat their mutual alloys as a group.