High Performance Synthetic Fibers for Composites (1992)
Chapter: Front Matter
NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance.
This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine.
The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Frank Press is president of the National Academy of Sciences.
The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsiblity for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Robert M. White is president of the National Academy of Engineering.
The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine.
The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy’s purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Frank Press and Dr. Robert M. White are chairman and vice chairman, respectively, of the National Research Council.
This study by the National Materials Advisory Board was conducted under Contracts No. MDA903-89-K-0078 and MDA 972-92-C-0028 with the U.S. Department of Defense and the National Aeronautics and Space Administration.
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ABSTRACT
This report describes the properties of the principal classes of high-performance synthetic fibers, as well as several current and potential methods of synthesis and processing to attain desirable properties. Various promising classes of materials and methods of fiber synthesis are suggested for further investigation.
Successful fiber reinforcement of a matrix is heavily dependent on the interface between the two components. The report emphasizes our relatively poor fundamental understanding of fiber-matrix reactions and this "interphase" region. Research directed at improving our understanding of the properties and behavior of the boundary region is identified as a prime need if advances are to be made in fiber and composite performance.
The report emphasizes the complex interdisciplinary nature of fiber science and makes strong policy recommendations for long-range continuity of fiber research and for increased support of education in fiber science.
Because of the highly international scope of the commercial fiber and composites industries and the critical importance of fibers for military and space applications, the report considers the consequences of government policy affecting these industries. Attention is called to the need for improving procedures leading to governmental decisions affecting the fiber industry.
The need for a policy to provide support for development and production of small quantities of specialty fibers for strategic military applications is also emphasized.
COMMITTEE ON HIGH-PERFORMANCE SYNTHETIC FIBERS
Chairman
RUSSELL J. DIEFENDORF,
Clemson University, Clemson, South Carolina
Members
CHARLES P. BEETZ, JR.,
Advanced Technology Materials, Inc., New Melford, Connecticut
GENE P. DAUMIT,
BASF Structural Materials, Inc., Charlotte, North Carolina
DANNY P. EDIE,
Clemson University, Clemson, South Carolina
MICHAEL JAFFE,
Hoechst Celanese Corporation, Summit, New Jersey
ARTHUR JAMES,
Lockheed Aerospace Systems Co., Burbank, California
RUEY LIN,
Howmedica, Rutherford, New Jersey
MANUEL PANAR,
E. I. duPont de Nemours & Co., Wilmington, Delaware
KARL M. PREWO,
United Technologies Research Center, East Hartford, Connecticut
THEODORE SCHOENBERG,
TEXTRON, Lowell, Massachusetts
JAMES SORENSON,
3M Company, St. Paul, Minnesota
HAROLD G. SOW-MAN,
3M Company (Retired), St. Paul, Minnesota
CARL H. ZWEBEN,
General Electric Company, Philadelphia, Pennsylvania
Liaison Representatives
BEN WILCOX,
Defense Advanced Research Projects Agency, Arlington, Virginia
WILLIAM MESSICK,
Naval Surface Warfare Center, Silver Spring, Maryland
JAMES DICARLO,
National Aeronautics and Space Administration-Lewis, Cleveland, Ohio
DANIEL R. MULVILLE,
National Aeronautics and Space Administration, Washington, D.C.
RICHARD DESPER,
Army Materials Technology Laboratory, Watertown, Massachusetts
MERRILL L. MINGES,
Wright Laboratory, Wright Patterson AFB, Ohio
JIM MANION,
Industrial Trade Administration, Department of Commerce, Washington, D.C.
NMAB Staff
JAMES H. SCHULMAN, Project Staff Officer
JANICE M. PRISCO, Administrative Assistant/Senior Project Assistant
PREFACE
High-performance synthetic fibers are key components of composite materials, a class of materials vital for U.S. military technology and for the civilian economy. The compositions of the fibers cover a wide range of chemical substances, including elementary carbon and boron, refractories such as inorganic carbides and oxides, and organic polymers. Fibrous forms of these materials are used to reinforce a similar range of matrix materials, and metals, producing composites with physical properties superior to those of unreinforced matrices. The emphasis in fiber research has been on the attainment of high-performance mechanical and thermal properties for structural applications, particularly for aerospace vehicles and aircraft.
The objective of this study is to survey major research and development opportunities for high-performance fibers needed for present and future structural composite applications and to identify steps that the federal government could take to accelerate the commercialization of this critical fiber technology in the United States. The report begins with background information on the fibers currently available for composite applications, their major uses, current and projected demands, costs, and sources of supply. New fibers and improvements in fiber properties that are needed for the various types of structural composites are discussed. The report then evaluates various approaches to fiber synthesis and processing that have the potential to either fulfill these needs or significantly reduce the cost of structural composites. The report also reviews ongoing research and development in areas that are of general importance to fiber science and technology (surface properties and treatments, fiber-matrix bonding, and fiber coatings and coating processes). Recommendations are made for future research that will be necessary to improve existing high-performance fibers and develop new ones. Included are specific steps that should be taken to ensure a domestic supply of existing and new high-performance fibers.
The report is concerned primarily with the reinforcing fibers needed in structural applications over the wide range of temperatures encompassed by organics, metals, and glass/ceramics. However, recognition is made of applications in which other useful physical properties of a fiber, such as electrical conductivity, thermal conductivity, magnetic or piezoelectric properties, allow the engineered structure to be dual or multipurpose.
Since high-performance fibers represent a new technology, in many cases only limited information exists. Thus, the length of the various sections in the report is not necessarily indicative of the importance of the topic covered.
Russel J. Diefendorf
Chairman
ACKNOWLEDGMENTS
The committee is especially grateful to the individuals who made formal presentations to the committee. At the first meeting, Joseph C. Jackson, executive director of SACMA, described SACMA's activities and offered the assistance of his organization to the committee members.
Speakers at the second meeting included William B. Hillig, General Electric Corporate Research and Development, who discussed potential composite systems and fibers; George F. Hurley, Los Alamos National Laboratory, who briefed the committee on whisker reinforcements; and Roger Bacon, AMOCO Performance Products, Inc., who talked about carbon fibers. Penny Azerdo, Pratt & Whitney Corporation, presented a paper on interactions in intermetallic systems; George Reynolds, MSNE, Inc., discussed interactions in ceramic systems; and committee member James Sorensen talked about interactions in high-temperature aircraft composites. Committee member Karl Prewo's presentation covered Japanese developments in fibers and committee member Ruey Y. Lin discussed chemical conversion of precursor fiber.
Presentations at the third meeting were made by Stanley Channon, consultant, who discussed a survey of world fiber production and technological capabilities; Joseph C. Jackson, SACMA, who described the comprehensive review his organization was preparing for a government presentation covering virtually all aspects of the fiber and composites industries; Greg Corman, General Electric (R&D), who talked about creep in single-crystal oxides; Ed Courtright, Battelle Pacific Northwest, who discussed oxygen permeability studies; Robert S. Feigelson, Stanford University, who discussed single-crystal preparation and properties, emphasizing the laser-heated pedestal growth technique; and Gary Tibbetts, General Motors Technology Center, who talked about carbon whiskers. These presentations proved to be valuable contributions to the technical contents of this report.
Special thanks also go to Donald E. Ellison, Donald E. Ellison & Associates, who supplied valuable input for the section on technology export and export control.
The chairman thanks the committee members for their dedication and for the patience shown during the numerous iterations and revisions of the report drafts. The liaison members are thanked for their active participation in committee discussions and for providing valuable support documents and data.
Finally, special thanks go to James H. Schulman, NMAB program officer, and Janice Prisco, project assistant, whose dedicated efforts made possible the production of this report.
TABLES AND FIGURES
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Table 1.1 |
High Performance Fibers |
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Table 1.2 |
Properties of polyamid in various forms |
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Table 2.1 |
Advantages of PMCs |
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Table 2.2 |
Advantage of PMCs |
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Table 2.3 |
Low-cost (aluminum-matrix) MMCs for Industrial and aerospace applications |
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Table 2.4 |
Some higher-cost MMC aerospace applications |
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Table 2.5 |
Some current high-performance-fiber reinforced MMC systems under development |
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Table 2.6 |
Commercially available fibers for the reinforcement of CMCs |
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Table 2.7 |
Manufacturing process for CMCs |
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Table 2.8 |
Some applications of CMCs |
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Table 2.9 |
Some current sources of CMCs |
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Table 2.10 |
Major uses of C-C composites |
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Table 3.1 |
Carbon fiber classification |
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Table 3.2 |
Oxide fibers |
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Table 3.3 |
Refractory fibers prepared by chemical conversion of a precursor fiber |
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Table 3.4 |
Comparative properties of reinforcing fibers |
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Table 3.5 |
Materials produced by CVD processes |
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Figure 1.1 |
Maximum-use temperatures of various structural materials |
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Figure 1.2 |
Strength of typical commercial organic fibers |
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Figure 1.3 |
Fiber price versus bundle size and fiber physical properties |
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Figure 1.4 |
Specific strength and modulus of high-performance fibers and other materials ''specific property'' means the property divided by the density |
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Figure 2.1 |
U.S. carbon fibers consumption by major market segment |
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Figure 2.2 |
U.S. carbon fiber consumption aerospace market |
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Figure 2.3 |
Comparison of bend tests for unreinforced cement and cement-matrix composites containing 2 percent chopped carbon fiber |
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Figure 2.4 |
Densities and use temperatures of potential composite matrices |
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Figure 2.5 |
Specific strength comparison of high-temperature metal alloys and advanced composites (two-dimentional fiber-matrix) |
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Figure 3.1 |
General processing steps for converting high bulk materials to fibers |
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Figure 3.2 |
Simplified flowsheet for precursor pyrloysis processes |
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Figure 3.3 |
PAN Based Process |
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Figure 3.4 |
Pitch based process |
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Figure 3.5 |
Production of Si ceramic fibers from polymetric precursors |
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Figure 3.6 |
Variation of tensile strength with flaw size |
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Figure 3.7 |
Scanning electron micrograph of fracture surface of mullite fiber |
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Figure 3.8 |
Transmission electron micrograph of ion milled section of mullite fiber |
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Figure 3.9 |
SEM of fiber FP surface |
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Figure 3.10 |
SEM of PRD-166 surface |
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Figure 3.11 |
Boron filiment reactor |
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Figure 3.12 |
Photomicrographics of boron fiber |
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Figure 3.13 |
Histogram of boron fiber tensile strength |
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Figure 3.14 |
Histogram of CVD SiC fiber tensil strength |
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Figure 3.15 |
Schematic drawing of the µ-/cz technique |
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Figure 3.16 |
Description of the production of vapour-grown fibres |
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Figure 3.17 |
Illustration of the VLS process for SiC whisker growth |
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Figure 3.18 |
A schemati diagram of the pedestal growth method |
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Figure 3.19 |
Schematic view of a continuous fiber electroplating process |
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Figure 3.20 |
Schematic diagram of the CVE process |
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Figure 3.21 |
Schematic of a continuous CVD fiber-coating line |
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Figure 3.22 |
Metallorganic deposition process |
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Figure 4.1 |
Structure and composition of SiC fiber produced by chemical vapor deposition |
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Figure 4.2 |
Interphase region produced during fabrication of Nicalon fiber reinforced glass-ceramics |
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Figure 4.3 |
Fracture surface of boron reinforced 6061 aluminum with prenotched region also shown |
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Figure 4.4 |
Fracture surface of Borsic reinforced titanium with prenotched region also shown |
