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acted upon by two separate types of organizational activities. The first is composed of the six government laboratories, such as the three GIRI laboratories that I visited in Osaka, Kyushu, and Nagoya. The second activity is composed of industrial laboratories and is under the supervision of the New Energy and Industrial Technology Development Organization (NEDO). Its aim is the rapid development of basic technologies that are considered essential to the growth of future industries. The fields covered by the program include new materials, biotechnology, new electronic devices and superconductivity, and project-related R&D that extends from the time a promising new technology is identified theoretically or experimentally to the time when its industrial application is established. Under these general categories, between 1981 and 1989, 14 specific "Research and Development Programs on Basic Technologies for Future Industries" have been established. The 11th one to be formed is "High Performance Materials for Severe Environments," which was established in 1989 and will run until 1996. This program is managed for NEDO by RIMCOFI.

Purpose and Functions of NEDO and RIMCOFI

NEDO was formed in 1981 and focuses its efforts on the research and development of industrial technology, particularly in basic and leading edge fields such as new materials and biotechnology. At the same time, it is sponsoring and taking the lead in establishing large scale advanced research facilities like the Japanese Ultra High Temperature Material Research Center (visited by me in March 1992).

Through such activities, NEDO is aiming at establishing innovative industrial technology that can support future programs like space travel and the conservation of energy and the earth's

atmosphere. NEDO is an implementation agency of the Japanese Government and receives its annual budget appropriations from MITI each year. To ensure further expeditious technological advances, NEDO has actively undertaken research and development projects. But NEDO has no research laboratories of its own and has no researchers on its staff. Its role is to administer, coordinate, and manage the research work undertaken by the national laboratories and industry. RIMCOFI assists in the fulfillment of this latter responsibility.

RIMCOFI is aiming towards inventing new high-temperature materials that are lightweight, corrosion proof, and abrasion proof by developing reinforcing types of fiber, matrix, and intermetallic compounds as well as the technology to integrate them into structural materials. With this information, it will be possible to design and introduce an entirely new generation of high speed transport aircraft for use in the early 21st century. To do so, it is first necessary to develop new materials that can withstand the extremely severe environmental conditions inherent to supersonic and hypersonic aircraft and space planes. The scope of the RIMCOFI program involves:

• Materials design

• Development of intermetallic compounds and reinforcement fibers

• Processing or fabrication technologies for thin sheets

• Oxidation resistance technologies

• Evaluation of thermal, mechanical, and chemical technologies

In the context of this study, the most urgent project facing RIMCOFI is to find a method of protecting C/Cs against oxidation in air. The target is 1,700 °C

for the first phase that is to be accomplished within the next 4 years. At this time, the approach is to use SiC for the coating. Beyond this, the goals are to operate for "200 hours at 1,800 °C and for one-third of an hour at 2,000 °C. Towards this end, several consortia have been formed. One consortium is Kobe Steel and Fugi Heavy Industry; they are investigating possible methods of oxidation protection where the C/C preforms are woven with Toray PAN fibers. The second consortium is composed of Fugi Heavy Industry and Nippon Steel. In this case, the fiber that is used for the preforms is pitch based rather than PAN. A third consortium that is investigating oxidation protection methods is Ishikawajima-Harima Heavy Industries Co., Ltd. and Tonen Corp. Only limited information was presented about the actual protection methods that are being investigated in the development of the coatings. In general, it appeared to be comparable to what was used for the U.S. shuttle some years ago. As expected, the results are comparable to the shuttle values up to 1,400 °C. But the Japanese test samples were only exposed to a few thermal cycles before the weight loss measurements were made. So this procedure is not as severe as they thought it should be for a proper evaluation.

Other organizations and the R&D efforts that are being addressed include: • Production of petroleum-based fibers

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from 22 industrial research supporting
members and 21 public supporting
members. Some of the organizations
that are involved include Kobe Steel,
Ltd.; Nippon Steel Corp.; Nissan Steel;
Nissan Motor; Nippon Carbon; Mitsui
Engineering & Shipbuilding; Mitsubishi
Heavy Industries, Ltd.; Kawasaki Steel
Corp.; Hitachi, Ltd.; Tonen Corp.; Toray
Industries, Inc.; Japan Aircraft Manu-
facturing Co.; Petoca Ltd.; Pratt and
Whitney; Rolls Royce; and many others.

RIMCOFI plays a vital role in the whole material developmental process by coordinating the activities of all these groups through enhancing the communication link between them by organizing and conducting topical seminars or progress/coordination meetings. For example, a recent seminar was held on 24-25 October 1990 titled "Basic Technologies for Future Industries, High Performance Materials for Severe Environments." In addition, there are about four to five coordination meetings held each month with one or another Assessment of the various groups. Another important aid for achieving better coordination and productivity is through the collection and dissemination by RIMCOFI of the most recent physical property data for all types of advanced composite materials. These data are collected and put into a computer system for easy retrieval by the members. In addition, the data have been compiled into a 1,000-page volume that was first published in 1990 and is available to the organization's members at no charge. However, the volume may also be acquired by the public for ¥55,000 (~$435). Data for the next volume are now being compiled.

It is the opinion of the directors of RIMCOFI that the ceramic matrix composite is the most immediate and available material for high temperature structural purposes. Consequently, more money is now being spent in this area and it will reach a maximum in 1992 because of the specialized equipment that needs to be procured to carry on the R&D efforts. However, it is also the directors' opinion that C/Cs will be the next generation of materials for high temperature applications and that C/C research must be conducted now if this material is to be available in a timely manner. It is expected that the research relating to C/Cs will continue to be supported by MITI at least until 1998 and possibly longer.

In addition to the funds received from MITI, RIMCOFI receives money

program and still make the original objectives even if there are strong indications that another approach might be advantageous.

Another aspect of the MITI organization and its approach is recognition that research and technology efforts and outputs can be enhanced by having organizations, like NEDO and RIMCOFI, that provide the staff for managing, coordinating, and enhancing communication between the various highly technical and diverse groups. As part of enhancing the effectiveness and communication between these groups, current physical property data about these materials are collected and disseminated on a timely basis. It appears that MITI and the Japanese Government recognize that devoting a minimal amount of nonresearch effort is necessary in order to have the research and development efforts proceed at a rapid pace. It is also necessary that the managers not be from one of the participating industrial organizations that are conducting part of the research efforts, thereby inhibiting one company from getting an advantage over its competitors.

This visit was most illuminating as to how the MITI operation is subdivided in order to enhance technical productivity by having an organizational activity that is specifically responsible for managing and maintaining excellent communications and good coordination between the participating groups. The general purpose for each phase of the program is clearly defined, but there is also flexibility for identifying and pursuing new directions that develop in the course of the program. This approach towards the development of new materials means there is the recognition that is takes time to evaluate the viability of any approach. But in the course of the planned research there may be alternative directions that are indicated that could be more fruitful if there was time to evaluate their potential. Under the NEDO charter, which FENG CHIA UNIVERSITY is applicable to RIMCOFI, such a mechanism exists for the pursuit of additional information. This is an aspect that is clearly missing in the U.S. system for developing C/C materials in two ways. First, there is not enough research effort and time allocated for Background developing advanced C/Cs. This means that instead of 3 to 5 years we are allowed 1 or possibly 2 years. Therefore, it is only possible to refine and scale up the existing processing procedures. Secondly, the budgets for research are so scaled down that there is no room to deviate from the original

It is recommended that further information be obtained about the pros and cons of the MITI system to determine if it can be used as a model for C/C R&D in the United States.

Dept. of Material Science
Taichung, Taiwan
Tel: (04) 252-2250 x5303
Dates: 16-17 Feb 1991

Prof. Tse Hao Ko was my host for this visit, and he is the head of the Carbon Fibers Research Group. His effort started over 10 years ago and is being supported by the Taiwan Government with the intent of developing methods of manufacturing fibers

for this country's own use and eventually for export. He is a frequent contributor of papers at the international carbon conferences. Several years ago, Ko spent a year at the Massachusetts Institute of Technology (MIT) studying carbon fiber interfaces and their bonding characteristics to metal matrix composites.

Program Status

Another major part of Ko's research is concerned with the treatment of the surfaces of fibers and the bonding phenomena that occur with different phenomena that occur with different types of organic matrices. Next, he plans to study the bonding characteristics of fibers in carbon matrices.

Ko's group consists of another university staff member, three graduate students, and four undergraduate students. The description of the measurements and characterization procedures that are being performed in connection with this research indicates there is available adequate laboratory capabilities, although I did not have the opportunity to see these facilities.

Although this research effort is not large, its directions appear to be innovative and it is expected this type of work will continue for many years. It is recommended that surveillance of these efforts be continued. Ko has indicated that collaboration with investigators in the United States is possible if there are areas of mutual interest.

CHUNG-SHAN INSTITUTE OF SCIENCE AND TECHNOLOGY

One of Ko's primary investigations is concerned with the variations of physical properties and microstructural changes in two different kinds of stabilized fibers. One kind is obtained from commercially available polyacrylonitrile (PAN) fibers and the other is developed Assessment from the same precursor source but it is then modified in Ko's laboratory. The purpose of this study is to understand if and how modifications of the precursor can make good quality fibers with higher tensile strengths. A special grade of PAN fiber tow was obtained from Courtaulds Ltd. that contained 6% methylacrylate and about 1% itaconic acid copolymer. The fibers from this tow were modified with hot potassium permanganate solution. The treated, untreated, and stabilized fibers were then heat treated at different temperatures between 300 and 1,300 °C. The tensile strengths, elemental impurity content, pore distribution, and crystalline structure were then determined. It has been found that the modified fibers, when compared to the stabilized but unmodified fibers, have a higher density, better preferred ori- Background entation, and 20% to 40% improvement in tensile strength. The fiber diameters are between 6 and 7 microns. The effects of different heat treatments above 1,300 °C on stabilized fibers are also being studied. One set that received 2,800 °C heat treatment temperature (HTT) had a very high modulus of 116 Mpsi and a strength of 290 kpsi.

Material R&D Center

P.O. Box 90008-8, Lung-Tan
Tao-yuan, Taiwan

Tel: (02) 3718105-2717
Fax: (03) 471-1024
Date: 19 Feb 1991

Prior to my visit, Prof. Ko gave me some background about this institute and how this visit occurred, since it was not on my original agenda. This is a paramilitary organization that is very well supported by the Government of Taiwan. It is a strictly controlled access facility where clearance is normally required. For example, Ko had never been in this institute until the day he

accompanied me, in spite of his long involvement in carbon research. I was asked to come here because my vita that was sent to Ko somehow had been seen by the institute's director of the Material R&D Center. The purpose of this entire institute, of which the center is only a part, is to produce military hardware starting with the research and going through the development and prototype stages to the production phase, if necessary, of the final hardware. Apparently, all of this is done mostly without the help of any organization or persons outside of this institute. Ko says that a great deal of money has been spent here on C/Cs for over 15 years. Once inside the controlled area and during the brief drive to the center, it was apparent the institute is a very large facility with more than eight large buildings that each contain about 6 to 8 stories. Each building must be over 100,000 ft2 in area.

Prof. Shu-en Hsu was my host for this visit. He is the director of the Material R&D Center and a professor at the National Taiwan University. It was he that arranged this meeting. A brief overview was presented by him of the major divisions that exist at the center. They are:

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Test Group conducts the measurements of mechanical and thermal properties, chemical and crystallographic analysis, and microscopy.

Special Materials prepared by plasma spraying, explosive and high energy electroforming, powder metallurgy.

• Solid State that includes single crystals, oxides, superconductors, diamonds, and electromagnetic (EM) shielding phenomena.

• Optical and Infrared (IR) Sensors

Approximately 500 persons work at the center: 50 have their M.S. or Ph.D. degrees, 200 have B.S. degrees, and the remainder of 250 are support people without degrees. The director spent considerable time showing me a variety of materials that had been developed and processed into hardware and different types of components for aircraft, missile systems, and other military hardware. The emphasis of his discussion was that this center was responsible for the development of a large variety of advanced materials and transferring this knowledge into procedures by which parts are made on a production basis sometimes with the assistance of industry. It certainly was an impressive display.

Program Status

C/Cs have been the subject of research here for the past 20 years according to Hsu. He says that they densify C/Cs by chemical vapor infiltration (CVI) and liquid impregnation methods and were the first organization in Asia to densify C/Cs by HIP procedures. The outer container of this 12-year-old facility is reported to be 7 feet in diameter with a working volume of 40 cm diameter and 60 cm long. They also weave one- (1D), two- (2D), and

three-dimensional (3D) preforms into various shapes. This includes 1-inchthick by 24-inch-diameter disks and 12by 12- by 12-inch 3D blocks. The block that was shown to me had yarns that were spaced 0.5 mm apart. Its density was reported to be >1.9 g/cc and its surface texture appeared to have an even distribution of very fine pores, which would be consistent with the high density. Its high density was obtained by HIPing to 15 kpsi to a maximum temperature of 600 °C using pitch for five cycles and HTT (<2,500 °C for 24 hours for thermal stability). The gas pressure inside the autoclave is applied after the temperature reaches 250 °C, which is different than is frequently used in the United States. The director said their HIP facility was the first one in Asia. The billet contains 55 Mpsi fibers that were bought abroad from Toho of Japan. Formerly they bought their fibers from Hercules Co. of the United States. Photomicrographs, using polarized light, showed each fiber in some of the C/Cs to be surrounded by a ring of amorphous carbon. But outside of this ring is a graphitic matrix that bonds or joins these coated fibers together. This combination of matrix microstructure is used with the intention of providing a specific combination of mechanical properties of high strength and modulus without a significant reduction of the work of fracture. Apparently the fracture surfaces showed a significant degree of fiber pullout, which is desirable if good utilization of the fiber's properties is to be obtained. It is very possible that this mixture of isotropic and graphitic microstructures that surrounds the fibers might give the desired properties. No details were given about the property values that are considered to be optimum. But this research direction does indicate the importance that is placed at this center on having the proper type of matrix microstructures.

Two other pieces of C/C were shown to me that are used for a gas diverter vane and a swivel rocket nozzle for vectoring. The nozzle has a 2-inch throat diameter and the piece had just been used in a test firing. Its internal surface looked very smooth without any trace of erosion. Polarized light microscopy is used to define the type of microstructure that exists in the C/Cs. Etching by oxidation is performed on some of the samples. Another variable that is used to attain different properties is the crosssectional shape of the yarns. Circularshaped yarns are used if high strength and isotropic properties are desired in C/Cs. Apparently, the yarns can be packed into a higher density in the C/Cs with the uniformly circular crosssectional yarns.

Subsequently, discussions were held with several of the younger staff members, who provided me with additional information about the status of the R&D investigations on C/Cs that are being conducted at the center. Some of the 3D C/Cs have bend and tensile strengths of 27 and 23 kpsi, respectively, and modulus of 100 Mpsi. The fibers that are frequently used come from Toho of Japan. The major success in the densification of C/Cs by the HIP method has occurred in the past 6 to 7 years. Other shapes of yarns can and have been used in producing various preforms. An unclassified article on some of the processing procedures has been published with the approximate title of "Super Alloy, Super Ceramic and Super Composites," Academic Press, 1988 or 1989, by Tien et al. Apparently, it has been found here that the best mechanical properties are obtained with a combination of CVI and liquid pitch impregnation method where CVI is used for the first and last densification steps and pitch is used for the intermediate steps. This sequence makes sense as the CVI bonds the fibers together if they are close together and

penetrates into the very fine pores that are formed during the pitch densification steps. The use of only CVI results in an inferior C/C because of the density gradients that are produced inside the preforms with this method of impregnation.

Detailed discussions showed that there is a sensitivity to the importance of processing conditions and the resulting microstructure and their influence on the physical properties of C/Cs.

In the future, this group will continue to develop new fabrication processes through an understanding of the phenomenology that causes the materials to behave as they do under severe environments. At the moment there are no big requirements for C/Cs for industrial purposes; thus, the research efforts at this center will continue at the present level in order to fill the military needs according to its director. An additional purpose at the center is to maintain an awareness of what is going on in the material field.

good quality and comparable to material that is fabricated in the United States. This could not have occurred without an understanding that is derived from some research. More importantly, there is good R&D being conducted here that they are willing to share. Otherwise, I would not have been invited to come and given special attention by the director for more than 2 hours. I was told afterwards that getting so much of the director's time is highly unusual. I think his motive is to show that significant work is going on at this center and that he is willing to have additional communications and perhaps collaboration with the United States. Therefore, it is recommended that continued communication be undertaken especially in the area of their optimization of matrix microstructure in C/Cs where collaboration might be beneficial to us.

The question of collaboration with
different U.S. organizations was brought
up by Prof. Hsu. He wishes to do this if
such joint efforts will be meaningful to
both parties. Apparently there is a
precedent already set; Pratt and Whitney
have just completed an agreement with
the center where there will be an inter-
change of scientists in the field of inter-
metallics. Also, the center has some
cooperative research work with the
University of Delaware. Hsu said that
uncooperative actions occurred at the
Cocoa Beach, Florida, meeting of the
American Ceramics Society, where his
man was asked to present a paper in the
closed session and then was asked to
leave the session while the rest of the
papers were being given. Hsu consid-
ered this procedure to be uncoopera- Background
tive and not conducive toward improv-
ing better communications.

NATIONAL TSING HUA
UNIVERSITY

Oxidation protection coating research is being conducted. The best result at this time is that no loss of the C/C substrates is noted after 60 hours at 1,600 °C. The coating is multilayer, with a composition of some combination of Zr and Si with a total thickness of all the layers between 50 and 100 microns. The inner layer, next to the substrate, is put on by applying a layer of silica powder that is converted to the carbide at 1,600 °C. Then, the outer layers are formed of mixtures containing Si and Zr powder that are applied and heat treated to 1,600 °C. The entire coating is oxidized in air. Some of the C/Cs have been coated with this material and then have been thermally cycled for 10 times. Upon evaluation no noticeable degradation or weight loss has occurred. No exact numerical figures were given to me. There is concern at the center with the differential thermal expansion problem that exists between the coatings and the C/C substrates. Thermal expansion tests are being Assessment conducted on these different materials, primarily as a means of quality control of the processing conditions. Apparently there is no research being undertaken to alter the coefficients of thermal expansion (CTEs) of the C/Cs.

The C/C research group consists of about five staff and five support people. Clearly, laboratory support for this R&D effort is available as was indicated by the above description of the organization by its director.

In general, this whole visit was very enlightening and totally unexpected because there is very little information that is published from the center. Yet, there is a significant amount of research and development work occurring here. The time at the center was limited, so it was difficult to evaluate the type and depth of research that was being conducted as opposed to good development work. However, the pieces of C/Cs that were shown to me appear to be of a

Institute of Chemical Engineering
No. 101, Sec. 2
Kuang Fu Road
Hsinchy, Taiwan 30043
Tel: (035) 715131 x3622
Date: 20 Feb 1991

My host for this site visit was Prof. Chen-Chi Ma of the Department of Chemical Engineering, which is a part of the Institute of Chemical Engineering. This is one of two universities in Taiwan that are involved in research areas that pertain to C/Cs and the only one that is especially concerned with woven structures that use carbon fibers. The primary thrust of the research at this university for the past 10 years has dealt with organic matrix composites, in particular, the mechanisms of reactions and bonding characteristics of the fibers in different mixtures of phenolic matrices. Now this research is shifting towards carbonaceous matrices.

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