Table Of ContentMETAL MATRIX COMPOSITES
A Study of Patents, Patent Applications
and Other Literature
METAL MATRIX COMPOSITES
A Study of Patents, Patent Applications
and Other Literature
Edited by
SEBASTIAAN A. GIESKES
and
MARTEN TERPSTRA
The Hague, The Netherlands
ELSEVIER APPLIED SCIENCE
LONDON and NEW YORK
ELSEVIER SCIENCE PUBLISHERS LTD
Crown House, Linton Road, Barking, Essex IGll 8JU, England
Sole Distributor in the USA and Canada
ELSEVIER SCIENCE PUBLISHING CO., INC.
655 Avenue of the Americas, New York, NY 10010, USA
WITH 28 TABLES AND 64 ILLUSTRATIONS
© 1991 ELSEVIER SCIENCE PUBLISHERS LTD
British Libory Cataloguing in Publiattion Data
Metal matrix composites.
1. Construction materials
I. Gieskes, Sebastiaan A. II. Terpstra, Marten
620.16
ISBN 1-85166-629-X
Libory of Congress CIP data applied for
No responsibility is assumed by the Publisher for any injury and/or damage to persons or property
as a matter of products liability, negligence or otherwise, or from any use or operation of any
methods, products, instructions or ideas contained in the material herein.
0
Special regulations for readers in the USA
This publication has been registered with the Copyright Clearance Centre Inc. (CCC), Salem,
Massachusetts. Information can be obtained from the CCC about conditions under which
photocopies of parts of this publication may be made in the USA. All other copyright questions,
including photocopying outside the USA, should be referred to the publisher.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or
transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or
otherwise, without the prior written permission of the publisher.
v
INTRODUCTION
The present study of patents and patent applications published in the United
States, Japan and the countries of Western Europe, and of other technological
literature published since about 1980, is the result of a comprehensive analysis
of documents which reveal various processes for reinforcing composite
materials by metals, the atoms of which have been arranged according to
predetermined matrices.
Pre-searches were conducted by the Patent Information Office of TNO in
Rijswijk, The Netherlands, which also provided copies of the documents
needed to carry out the analysis. The International Patent Classification
System (IPC) was employed to determine proper entries to the documents on
the respective subject-matter. These classes are:
C 22 C 1/09 relating to alloys containing metallic or non-metallic fibres or
filaments;
/09B by subjecting to pressure and heat an assembly comprising at
least one metal layer or sheet and one layer of fibres or
filaments;
/09C by contacting the filaments or fibres with molten metal, e.g. by
impregnation;
/09D by using a powder-metallurgical method;
/09F characterized by the material used respectively for the metal
matrix or the reinforcing fibres;
/09F2 matrix formed of a light metal such as AI, Mg, Be, Ti;
/09F4 matrix formed of a refractory metal such as Ni, Co, Cr, Mo.
Classifying patents or patent applications is actually a very difficult matter,
particularly when it has to deal with processes for the production of
composites, metal alloys or pharmaceuticals.
Although, generally speak,ing, classifying such materials could be effected by
arranging them according to their basic components having the highest
percentages by weight in the material, it is well known in the art that the
properties of such materials can be substantially changed by adding small or
very small amounts of additives different from those basic materials.
As a consequence, the editors have systematized their analysis according to
the major ingredients present in the composites, but they have added
sub-headings referring to those additives which may substantially change the
properties of the respective composite.
vi
The present literature analysis comprises approximately 200 primary patents
and patent applications, covering substantially the prior art situation of the
subject-matter since about 1980, and also covers a number of articles from
journals which were partly derived from the introductory sections of the patent
specifications studied or else from the results of a computer search at the
Technical University, Delft, The Netherlands.
The editors are grateful to those colleagues who were very cooperative in
selecting proper documents, particularly but not exclusively to the colleagues
of the Patent Information Office of TNO mentioned above. Finally, the editors
and the publishers of the present study owe their gratitude to the officials of
the Commission of European Community, Directorate-General XIII, Luxem
bourg, who were prepared to contribute to the cost of conducting the analysis.
SEBASTIAAN A. GIESKES
MARTEN TERPSTRA
vii
CONTENTS
Introduction. .. .. .. .. . .. . .. . . .. .. .. . . .... .... ....... ..... .... . . . .. . .. . .. .. .. . .. . .. ... v
1.0 Reinforced Composites of Aluminium and/or Magnesium ............. 1
1.1 Reinforced Aluminium Composites ............................................. 1
1.2 Reinforced Aluminium and/or Magnesium-Based Composites .......... 49
1.3 Reinforced Magnesium Composites ............................................. 75
2.0 Reinforced Composites Based on Titanium ................................ 80
3.0 Reinforced Composites Based on Copper .................................. 94
4.0 Reinforced Composites Based on Miscellaneous Metals ................ 97
4.1 Miscellaneous Reinforced Metal Based Composites: Cu, W, Mo, Fe,
Ni, Co: A1203, Si3N4, Zr02, W ................................................... 97
5.0 Apparatus and/or Procedures for the Fabrication of Reinforced
Metal Composites ................................................................. 127
5.1 Miscellaneous Composites ......................................................... 127
5.2 Cu-Based Composites............................................................... 147
5.3 Ti-Based Composites................................................................ 149
5.4 Miscellaneous Concerning Fibres for the Fabrication of Reinforced
Metal Composites .................................................................... 154
6.0 Cermets............. ....................................... .......................... 182
7.0 Applications of Reinforced Metal Composites ............. ............... 186
7.1 Miscellaneous Applications ........................................................ 186
7.2 Applications of Reinforced Aluminium Composites ............ ............ 194
7.3 Applications of Reinforced Composites Based on Aluminium or
Magnesium ............................................................................. 204
7.4 Applications of Composites Based on Copper ............................... 206
7.5 Applications of Composites Based on Silver .................................. 210
7.6 Applications of Reinforced Composites Based on Iron or Steel......... 213
7.7 Cermets Reinforced by TiC, WC, or TaC ..................................... 225
Abbreviations Used ............................................................... 227
List of Patentees ................................................................... 229
1
1.0 REINFORCED COMPOSITES OF ALUMINIUM AND/OR MAGNESIUM.
1.1 REINFORCED ALUMINIUM COMPOSITES.
Co, Cu.
Typical for the area of the Al conductor art are United States patents nos.
3 807 969 and 3 830 635. They concern Al-alloys, containing small
percentages of Ni and Co. United States patent no. 3 872 917 discloses an
Al-Fe all which is cast and processed to produce a microstructure which
contains intermetallic particles of A1 Fe. United States patent no. 3 989
3
548 describes an alloy containing 5-20 vol.% of fibrous intermetallic
components with transition metals.
Morris J.G. et al, (UNITED TECHNOLOGY CORP. (81.3», developed a process
for making a high ductility, high strength, moderate conductivity Al
conductor article.
It comprises an Al matrix, containing 0.75-1.0% Cu, and 1.0-2.0% Co.
The eutectic is selected so that the volume fraction of the second phase,
which forms in the Al matrix is relatively small, resulting in a minimal
reduction of the conductivity by the less-conductive second phase.
For strengthening purposes at least 1 vol.% fibres is needed, but more than
4 vol.% would reduce the conductivity. Secondly, the solid solubility of
the eutectic constituents in the Al matrix must be minimal. The third
condition is that it can be solidified by coupled growth, i.e. both of the
eutectic phases form simultaneously at the solidification interface and
therefore both phases are continuous in the direction of motion of the
solidification interface, and that no primary dendritic phases form. A
final condition is that the coupled growth of the eutectic must be possible
even when as much as 1.5% of Cu is added to the composition and the
eutectic should be of a composition in which the the Cu will partition to
the matrix phase rather than to the fibrous phase. The additional Cu
renders the composition heat treatable and provides surprising ductilities
under certain conditions of heat-treatment. There are several known
eutectic compositions which fulfill the conditions set forth above.
2
several Al and Be eutectics do qualify technically, the toxicity of Be
li.its, however, their applicability.
The preferred eutectic syst. . is based on the Al-Co eutectic (with an
addition of Cu) and the equilibrium eutectic composition is about 1% Co.
Growth will occur and a fully eutectic structure will result for Co levels
of about 1% at very slow solidification rates. As this rate increases, it
is necessary to increase the Co level, if fully coupled growth is to be
..i ntained.
E.g. solidification rates of 2 cm/hr require Co levels of about 1%, while a
solidification rate about 500 cm/hr requires Co levels of about 1.65% to
..i ntain fully coupled growth. The presence of the primary metallic phase
(A1gCoz) is undesirable for reasons described below. The primary phase has
low electrical conductivity and high strength but .inimal ductility. The
brittle nature of the intermetal1ic phase makes it unlikely that wire could
be successfully produced by conventional means from material containing too
much of the primary intermeta1lic phase. Therefore, the starting
cOlposition and the castings conditions have to be correlated to produce a
microstructure which is free from the primary Al-Co phase.
The primary Al phase has high conductivity and low strength, but is
ductile. Since primary A1 is less detrimental, it can be more readily
tolerated than the primary intermeta11ic phase. The primary Al phase should
not exceed 30 vol.%. Increasing amounts lead to a decrease in mechanical
properties, except for ductility, but this may be tolerated for many
applications. Intentional additions of Cu in amounts of about 0.5-1.5% are
..d e to the basic A1-Co eutectic. Cu levels of 0.75-1.0% are preferred, or
about 25% of the Co may be replaced with Fe.
The essential parameters which define solidification are G, the thermal
gradient in the liquid across the solidification interface, and R, the rate
of the .avement of the solidification interface. The ratio GIR deter.ines
the essential solidification characteristics. For extremely high values of
G/R plane front solidification will occur, i.e. the front is planar and all
of the second phase elements which form normal to the solidification front,
will be parallel, this is termed plane front directional solidification.
Lower values of GIR result in a roughened solidification front, the
microstructure will be cellular and the second phases will not be
ca.pletely parallel to each other. This is ter.ed directional cellular
growth and produces a colony type of microstructure. Finally, for very low
values of GIR, the .icrostructure will become dendritic, consisting of
3
large dendrites of the primary phases. In the Al-Co+Cu system, G/R ratios
in excess of about 0.5 °C.hrcm-2 have been observed to lead to plane front
coupled growth. Plane front and cellular solidification both involve
coupled growth. Fibre diameters are inversely related to R. High R values
produce fine fibres. The preferred range of fibre diameters is about 0.01-2
IJ.III.
The alloys are he~t-treatable and can be strengthened by a precipitation
hardening mechanism. Figure 1.1 shows the solvus curve for Cu-Al-alloys. At
equilibrium, composition-temperature combinations above the curve will be
solid solutions, while those below will contain Cu-rich precipitate
particles.
Fig. 1.1:
eoo
TEt.4p, ·c
200
100
oo~ --~----~-2 ---~-3 ---~4- ---L5- ----
~ Cu
It is common practice to heat-treat such alloys by first heating above the
solvus then rapidly cooling below the solvus to produce an unstable (super
saturated) material and then reheating it at a lower temperature to permit
precipitation to occur. The materials,developed by the authors, may be
solution heat-treated by heating to a point above the curve for a period of
time of about 0.17-10 hrs. and then cooling rapidly to a temperature below
the solvus so as to suppress precipitation. Since the solution treatment
temperature is above the recrystallization temperature, the solution
treatment should be performed before the cold-working step. Aging may then
°c
be performed at a lower ta.perature as e.g. 12-93 below the solvus for a
4
time of about 0.17-30 hrs. The aging temperature should be selected below
the recrystallization or annealing temperature. The aging step may be
performed before or after the cold-working step or as an intermediate
operation.
After the solidification, the material is mechanically worked into wire by
using conventional techniques. In tests involving swaging, it was found
possible to reduce the cross-sectional area by as much as 98% without
intermediate anneals. This is an indication of the great ductility of the
material. Even after such a reduction it still had a significant amount of
ductility. Alternately, the material may be initially hot-worked and then
cold-worked to the final gauge. Of course, any heat-treatment operation
should be performed after the last hot-working operation. In order to
achieve reasonable mechanical properties in the finished wire, it is
necessary that the finished wire be in a cold-worked condition and that the
wire has been cold-worked at least 80%.
In the -as cast- condition the Al eutectic material will contain elongated
second phase (intermetallic) fibres, which have an aspect ratio of at least
10. Usually, it will be much greater and in the case of material produced
by plane front solidification it may be easily in excess of 1000. The fibre
diameters will range from 0.01-2 Finer diameters are wanted when
~.
maximum mechanical properties are desired, but coarser diameters will be
more resistant to thermal degradation. The -as cast- material will usually
have an elongated external geometry and the working processes employed to
reduce the material to wire will elongate the material in the direction of
its original axis of elongation. The effect of mechanical working will be
to break up the fibres so that their average aspect ratio is less than 5.
Working operations will align the fibre fragments in the direction of the
axis of elongation of the wire conductor.
Table 1.1 shows the properties of series of alloys according to the
process. All materials were directionally solidified (a coupled growth
process) at 500 cm/hr. Solution heat-treatment was performed at 500 °C for
hrs. Annealing was performed at 370 °C for 10 hrs. Aging was performed at
190 °C for 24 hrs. (1 ksi = 6.895 MPa)
The effect of increase in Cu can be seen as an increase in ultimate tensile
strength and a decrease in conductivity. Higher Cu levels also appear to
increase the elongation some extent.
Comparing the B materials with A materials shows the effect of the addition
of the solution heat-treatment in the elongations and conductivity values.
