Lapas attēli

acted upon by two separate types of atmosphere. NEDO is an implementa- for the first phase that is to be accomorganizational activities. The first is tion agency of the Japanese Government plished within the next 4 years. At this composed of the six government labo- and receives its annual budget appro- time, the approach is to use SiC for the ratories, such as the three GIRI labora- priations from MITI each year. To ensure coating. Beyond this, the goals are to tories that I visited in Osaka, Kyushu, further expeditious technological operate for 200 hours at 1,800 °C and and Nagoya. The second activity is advances, NEDO has actively under- for one-third of an hour at 2,000 °C. composed of industrial laboratories and taken research and development proj- Towards this end, several consortia have is under the supervision of the New ects. But NEDO has no research labo- been formed. One consortium is Kobe Energy and Industrial Technology ratories of its own and has no researchers Steeland Fugi Heavy Industry; they are Development Organization (NEDO). on its staff. Its role is to administer, investigating possible methods of oxiIts aim is the rapid development of coordinate, and manage the research dation protection where the C/C basic technologies that are considered work undertaken by the national labora- preforms are woven with Toray PAN essential to the growth of future indus- tories and industry. RIMCOFI assists fibers. The second consortium is tries. The fields covered by the pro- in the fulfillment of this latter composed of Fugi Heavy Industry and gram include new materials, biotech- responsibility.

Nippon Steel. In this case, the fiber nology, new electronic devices and RIMCOFI is aiming towards invent- that is used for the preforms is pitch superconductivity, and project-related ing new high-temperature materials that based rather than PAN. A third R&D that extends from the time a are lightweight, corrosion proof, and consortium that is investigating promising new technology is identified abrasion proof by developing reinforc- oxidation protection methods is theoretically or experimentally to the ing types of fiber, matrix, and inter- Ishikawajima-Harima Heavy Industries time when its industrial application is metallic compounds as well as the tech- Co., Ltd. and Tonen Corp. Only limited established. Under these general cate- nology to integrate them into struc- information was presented about the gories, between 1981 and 1989, 14 tural materials. With this information, actual protection methods that are being specific “Research and Development it will be possible to design and intro- investigated in the development of the Programs on Basic Technologies for ducean entirely new generation of high

duce an entirely new generation of high coatings. In general, it appeared to be Future Industries" have been estab- speed transport aircraft for use in the comparable to what was used for the lished. The 11th one to be formed is early 21st century. To do so, it is first U.S. shuttle some years ago. As expected, “High Performance Materials for Severe necessary to develop new materials that the results are comparable to the shuttle Environments," which was established can withstand the extremely severe values up to 1,400 °C. But the Japanese in 1989 and will run until 1996. This environmental conditions inherent to test samples were only exposed to a few program is managed for NEDO by supersonic and hypersonic aircraft and thermal cycles before the weight loss RIMCOFI.

space planes. The scope of the RIMCOFI measurements were made. So this program involves:

procedure is not as severe as they thought Purpose and Functions of

it should be for a proper evaluation. NEDO and RIMCOFI • Materials design

Other organizations and the R&D

efforts that are being addressed include: NEDO was formed in 1981 and • Development of intermetallic comfocuses its efforts on the research and pounds and reinforcement fibers • Production of petroleum-based development of industrial technology,

fibers particularly in basic and leading edge • Processing or fabrication technolofields such as new materials and bio- gies for thin sheets

Petoca, Ltd. technology. At the same time, it is

Nippon Petrochemicals Co., Ltd. sponsoring and taking the lead in estab- • Oxidation resistance technologies

Tonen Corp. lishing large scale advanced research facilities like the Japanese Ultra High • Evaluation of thermal, mechanical, • Processing and fabrication of C/Cs Temperature Material Research Cen- and chemical technologies ter (visited by me in March 1992).

Nissan Motor Co. Through such activities, NEDO is In the context of this study, the most Mitsubishi Heavy Industries, Ltd. aiming at establishing innovative urgent project facing RIMCOFI is to Kawasaki Heavy Industries, Ltd. industrial technology that can support find a method of protecting C/Cs against Matsushita Electric Industrial Co. future programs like space travel and oxidation in air. The target is 1,700 °C Ltd. the conservation of energy and the earth's

Petroleum Energy Center

RIMCOFI plays a vital role in the from 22 industrial research supporting program and still make the original whole material developmental process members and 21 public supporting objectives even if there are strong indiby coordinating the activities of all these members. Some of the organizations cations that another approach might groups through enhancing the com- that are involved include Kobe Steel, be advantageous. munication link between them byorga- Ltd.; Nippon Steel Corp.; Nissan Steel; Another aspect of the MITIorganinizing and conducting topical semi. Nissan Motor; Nippon Carbon; Mitsui zation and its approach is recognition nars or progress/coordination meetings. Engineering & Shipbuilding Mitsubishi that research and technology efforts For example, a recent seminar was held Heavy Industries, Ltd.; Kawasaki Steel and outputs can be enhanced by having on 24-25 October 1990 titled “Basic Corp.; Hitachi, Ltd.; Tonen Corp.; Toray organizations, like NEDO and Technologies for Future Industries, Industries, Inc.; Japan Aircraft Manu- RIMCOFI, that provide the staff for High Performance Materials for Severe facturing Co.; Petoca Ltd.; Pratt and managing, coordinating, and enhancEnvironments.” In addition, there are Whitney; Rolls Royce; and many others. ing communication between the variabout four to five coordination meet

ous highly technical and diverse groups. ings held each month with one or another Assessment

As part of enhancing the effectiveness of the various groups. Another impor

and communication between these tant aid for achieving better coordina- This visit was most illuminating as groups, current physical property data tion and productivity is through the to how the MITI operation is subdivided about these materials are collected and collection and dissemination by in order to enhance technical produc- disseminated on a timely basis. It appears RIMCOFI of the most recent physical tivity by having an organizational activ- that MITI and the Japanese Government property data for all types of advanced ity that is specifically responsible for recognize that devoting a minimal composite materials. These data are managing and maintaining excellent amount of nonresearch effort is necescollected and put into a computer sys- communications and good coordina- sary in order to have the research and tem for easy retrieval by the members. tion between the participating groups. development efforts proceed at a rapid In addition, the data have been com- The general purpose for each phase of pace. It is also necessary that the piled into a 1,000-page volume that the program is clearly defined, but there managers not be from one of the parwas first published in 1990 and is avail- is also flexibility for identifying and ticipating industrial organizations that able to the organization's members at pursuing new directions that develop are conducting part of the research no charge. However, the volume may in the course of the program. This efforts, thereby inhibiting one company also be acquired by the public for Y55,000 approach towards the development of from getting an advantage over its (-$435). Data for the next volume are new materials means there is the recog- competitors. now being compiled.

nition that is takes time to evaluate the It is recommended that further It is the opinion of the directors of viability of any approach. But in the information be obtained about the pros RIMCOFI that the ceramic matrix course of the planned research there and cons of the MITI system to determine composite is the most immediate and may be alternative directions that are if it can be used as a model for C/C available material for high tempera- indicated that could be more fruitful if R&D in the United States. ture structural purposes. Consequently, there was time to evaluate their potenmore money is now being spent in this tial. Under the NEDO charter, which FENG CHIA UNIVERSITY area and it will reach a maximum in is applicable to RIMCOFI, such a 1992 because of the specialized equip- mechanism exists for the pursuit of Dept. of Material Science ment that needs to be procured to carry additional information. This is an aspect Taichung, Taiwan on the R&D efforts. However, it is also that is clearly missing in the U.S. sys- Tel: (04) 252-2250 x5303 the directors'opinion that C/Cs will be tem for developing C/C materials in Dates: 16-17 Feb 1991 the next generation of materials for two ways. First, there is not enough high temperature applications and that research effort and time allocated for Background C/C research must be conducted now if developing advanced C/Cs. This means this material is to be available in a that instead of 3 to 5 years we are Prof. Tse Hao Ko was my host for timely manner. It is expected that the allowed 1 or possibly 2 years. There- this visit, and he is the head of the research relating to C/Cs will continue fore, it is only possible to refine and Carbon Fibers Research Group. His to be supported by MITI at least until scale up the existing processing proce- effort started over 10 years ago and is 1998 and possibly longer.

dures. Secondly, the budgets for research being supported by the Taiwan In addition to the funds received are so scaled down that there is no Government with the intent of develfrom MITI, RIMCOFI receives money room to deviate from the original oping methods of manufacturing fibers

for this country's own use and even- Another major part of Ko's research accompanied me, in spite of his long tually for export. He is a frequent con- is concerned with the treatment of the involvement in carbon research. I was tributor of papers at the international surfaces of fibers and the bonding asked to come here because my vita carbon conferences. Several years ago, phenomena that occur with different that was sent to Ko somehow had been Ko spent a year at the Massachusetts types of organic matrices. Next, he plans seen by the institute's director of the Institute of Technology (MIT) study- to study the bonding characteristics of Material R&D Center. The purpose of ing carbon fiber interfaces and their fibers in carbon matrices.

this entire institute, of which the center bonding characteristics to metal matrix Ko's group consists of another uni- is only a part, is to produce military composites.

versity staff member, three graduate hardware starting with the research and

students, and four undergraduate stu- going through the development and Program Status

dents. The description of the measure- prototype stages to the production

ments and characterization procedures phase, if necessary, of the final hardOne of Ko's primary investigations that are being performed in connec- ware. Apparently, all of this is done is concerned with the variations of tion with this research indicates there

tion with this research indicates there mostly without the help of any organiphysical properties and microstructural is available adequate laboratory capa- zation or persons outside of this instichanges in two different kinds of stabi- bilities, although I did not have the tute. Ko says that a great deal of money lized fibers. One kind is obtained from opportunity to see these facilities. has been spent here on C/Cs for over commercially available polyacrylonitrile

15 years. Once inside the controlled (PAN) fibers and the other is developed Assessment

area and during the brief drive to the from the same precursor source but it

center, it was apparent the institute is a is then modified in Ko's laboratory. Although this research effort is not very large facility with more than eight The purpose of this study is to under- large, its directions appear to be inno- large buildings that each contain about stand if and how modifications of the vative and it is expected this type of 6 to 8 stories. Each building must be precursor can make good quality fibers work will continue for many years. It is over 100,000 ftin area. with higher tensile strengths. A special recommended that surveillance of these Prof. Shu-en Hsu was my host for grade of PAN fiber tow was obtained efforts be continued. Ko has indicated this visit. He is the director of the from Courtaulds Ltd. that contained that collaboration with investigators in Material R&D Center and a professor 6% methylacrylate and about 1% the United States is possible if there at the National Taiwan University. It itaconic acid copolymer. The fibers from are areas of mutual interest.

was he that arranged this meeting. A this tow were modified with hot potas

brief overview was presented by him of sium permanganate solution. The CHUNG-SHAN INSTITUTE OF

CHUNG-SHAN INSTITUTE OF the major divisions that exist at the treated, untreated, and stabilized fibers SCIENCE AND TECHNOLOGY center. They are: were then heat treated at different temperatures between 300 and 1,300 °C. Material R&D Center

• High Temperature Materials, which The tensile strengths, elemental impurity P.O. Box 90008-8, Lung-Tan

includes ceramics both in bulk and content, pore distribution, and Tao-yuan, Taiwan

composite form, C/Cs, powder crystalline structure were then deter- Tel: (02) 3718105-2717

metallurgy, radomes. mined. It has been found that the Fax: (03) 471-1024 modified fibers, when compared to the Date: 19 Feb 1991

Composites, including structural, stabilized but unmodified fibers, have

thermal insulators, metal matrix, and a higher density, better preferred ori- Background

high temperature polymers that are entation, and 20% to 40% improve

used up to 1,000 °C for very short ment in tensile strength. The fiber diam- Prior to my visit, Prof. Ko gave me

periods of time. eters are between 6 and 7 microns. The some background about this institute effects of different heat treatments above and how this visit occurred, since it was • Electric Power Batteries for mis1,300 °C on stabilized fibers are also not on my original agenda. This is a siles. All electrical characterization being studied. One set that received paramilitary organization that is very measurements are conducted here 2,800 °C heat treatment temperature well supported by the Government of for the center. (HTT) had a very high modulus of Taiwan. It is a strictly controlled access 116 Mpsi and a strength of 290 kpsi. facility where clearance is normally

• Conventional Metallurgy of superrequired. For example, Ko had never alloys and castings. been in this institute until the day he

• Test Group conducts the measure- three-dimensional (3D) preforms into Two other pieces of C/C were shown

ments of mechanical and thermal various shapes. This includes 1-inch- to me that are used for a gas diverter properties, chemical and crystallo- thick by 24-inch-diameter disks and 12- vane and a swivel rocket nozzle for graphic analysis, and microscopy. by 12- by 12-inch 3D blocks. The block vectoring. The nozzle has a 2-inch throat

that was shown to me had yarns that diameter and the piece had just been • Special Materials prepared by plasma were spaced 0.5 mm apart. Its density

were spaced 0.5 mm apart. Its density used in a test firing. Its internal surface spraying, explosive and high energy was reported to be >1.9 g/cc and its looked very smooth without any trace electroforming, powder metallurgy. surface texture appeared to have an of erosion. Polarized light microscopy

even distribution of very fine pores, is used to define the type of microstruc• Solid State that includes single crys- which would be consistent with the ture that exists in the C/Cs. Etching by

tals, oxides, superconductors, dia- high density. Its high density was oxidation is performed on some of the monds, and electromagnetic (EM) obtained by HIPing to 15 kpsi to a samples. Another variable that is used shielding phenomena.

maximum temperature of 600 °C using to attain different properties is the CTOSS

pitch for five cycles and HTT(<2,500°C sectional shape of the yarns. Circular• Optical and Infrared (IR) Sensors for 24 hours for thermal stability). The shaped yarns are used if high strength

gas pressure inside the autoclave is and isotropic properties are desired in Approximately 500 persons work at applied after the temperature reaches C/Cs. Apparently, the yarns can be the center: 50 have their M.S. or Ph.D. 250 °C, which is different than is fre- packed into a higher density in the degrees, 200 have B.S. degrees, and the quently used in the United States. The C/Cs with the uniformly circular crossremainder of 250 are support people director said their HIP facility was the sectional yarns. without degrees. The director spent first one in Asia. The billet contains Subsequently, discussions were held considerable time showing me a vari- 55 Mpsi fibers that were bought abroad with several of the younger staff memety of materials that had been devel- from Toho of Japan. Formerly they bers, who provided me with additional oped and processed into hardware and bought their fibers from Hercules Co. information about the status of the different types of components for air- of the United States. Photomicrographs, R&D investigations on C/Cs that are craft, missile systems, and other mili- using polarized light, showed each fiber being conducted at the center. Some of tary hardware. The emphasis of his in some of the C/Cs to be surrounded the 3D C/Cs have bend and tensile discussion was that this center was by a ring of amorphous carbon. But strengths of 27 and 23 kpsi, respecresponsible for the development of a outside of this ring is a graphitic matrix tively, and modulus of 100 Mpsi. The large variety of advanced materials and that bonds or joins these coated fibers fibers that are frequently used come transferring this knowledge into pro- together. This combination of matrix from Toho of Japan. The major success cedures by which parts are made on a microstructure is used with the inten- in the densification of C/Cs by the HIP production basis sometimes with the tion of providing a specific combina- method has occurred in the past 6 to assistance of industry. It certainly was tion of mechanical properties of high 7 years. Other shapes of yarns can and an impressive display.

strength and modulus without a signif- have been used in producing various

icant reduction of the work of fracture. preforms. An unclassified article on Program Status

Apparently the fracture surfaces showed some of the processing procedures has

a significant degree of fiber pullout, been published with the approximate C/Cs have been the subject of which is desirable if good utilization of title of “Super Alloy, Super Ceramic research here for the past 20 years the fiber's properties is to be obtained. and Super Composites,” Academic according to Hsu. He says that they It is very possible that this mixture of Press, 1988 or 1989, by Tien et al. densify C/Cs by chemical vapor insil- isotropic and graphitic microstructures Apparently, it has been found here that tration (CVI) and liquid impregnation that surrounds the fibers might give the the best mechanical properties are methods and were the first organiza- desired properties. No details were given obtained with a combination of CVI tion in Asia to densify C/Cs by HIP about the property values that are and liquid pitch impregnation method procedures. The outer container of this considered to be optimum. But this where CVI is used for the first and last 12-year-old facility is reported to be research direction does indicate the densification steps and pitch is used for 7 feet in diameter with a working volume importance that is placed at this center the intermediate steps. This sequence of 40 cm diameter and 60 cm long. They on having the proper type of matrix makes sense as the CVI bonds the fibers also weave one- (1D), two- (2D), and microstructures.

together if they are close together and penetrates into the very fine pores that In the future, this group will con- good quality and comparable to material are formed during the pitch densifica- tinue to develop new fabrication pro- that is fabricated in the United States. tion steps. The use of only CVI results cesses through an understanding of the This could not have occurred without in an inferior C/C because of the den- phenomenology that causes the mate- an understanding that is derived from sity gradients that are produced inside rials to behave as they do under severe some research. More importantly, there the preforms with this method of impreg- environments. At the moment there is good R&D being conducted here nation.

are no big requirements for C/Cs for that they are willing to share. Otherwise, Detailed discussions showed that industrial purposes; thus, the research I would not have been invited to come there is a sensitivity to the importance efforts at this center will continue at and given special attention by the of processing conditions and the result- the present level in order to fill the director for more than 2 hours. I was ing microstructure and their influence military needs according to its director. told afterwards that getting so much of on the physical properties of C/Cs. An additional purpose at the center is the director's time is highly unusual. I

Oxidation protection coating to maintain an awareness of what is think his motive is to show that signifresearch is being conducted. The best going on in the material field.

icant work is going on at this center and result at this time is that no loss of the The question of collaboration with that he is willing to have additional C/C substrates is noted after 60 hours different U.S. organizations was brought communications and perhaps collaboat 1,600 °C. The coating is multilayer, up by Prof. Hsu. He wishes to do this ifration with the United States. Therewith a composition of some combina- such joint efforts will be meaningful to fore, it is recommended that continued tion of Zr and Si with a total thickness both parties. Apparently there is a communication be undertaken espeof all the layers between 50 and 100 precedent already set; Pratt and Whitney cially in the area of their optimization microns. The inner layer, next to the have just completed an agreement with of matrix microstructure in C/Cs where substrate, is put on by applying a layer the center where there will be an inter- collaboration might be beneficial to us. of silica powder that is converted to the change ofscientists in the field of intercarbide at 1,600 °C. Then, the outer metallics. Also, the center has some NATIONAL TSING HUA layers are formed of mixtures contain- cooperative research work with the UNIVERSITY ing Si and Zr powder that are applied University of Delaware. Hsu said that and heat treated to 1,600°C. The entire uncooperative actions occurred at the Institute of Chemical Engineering coating is oxidized in air. Some of the Cocoa Beach, Florida, meeting of the No. 101, Sec. 2 C/Cs have been coated with this mate- American Ceramics Society, where his Kuang Fu Road rial and then have been thermally cycled man was asked to present a paper in the Hsinchy, Taiwan 30043 for 10 times. Upon evaluation no notice- closed session and then was asked to Tel: (035) 715131 x3622 able degradation or weight loss has leave the session while the rest of the Date: 20 Feb 1991 occurred. No exact numerical figures papers were being given. Hsu considwere given to me. There is concern at ered this procedure to be uncoopera- Background the center with the differential thermal tive and not conducive toward improvexpansion problem that exists between ing better communications.

My host for this site visit was Prof. the coatings and the C/C substrates.

Chen-Chi Ma of the Department of Thermal expansion tests are being Assessment

Chemical Engineering, which is a part conducted on these different materials,

of the Institute of Chemical Engineerprimarily as a means of quality control In general, this whole visit was very ing. This is one of two universities in of the processing conditions. Appar- enlightening and totally unexpected Taiwan that are involved in research ently there is no research being under- because there is very little information areas that pertain to C/Cs and the only taken to alter the coefficients of ther- that is published from the center. Yet, one that is especially concerned with mal expansion (CTES) of the C/Cs. there is a significant amount of research woven structures that use carbon fibers.

The C/C research group consists of and development work occurring here. The primary thrust of the research at about five staff and five support people. The time at the center was limited, so it this university for the past 10 years has Clearly, laboratory support for this R&D was difficult to evaluate the type and dealt with organic matrix composites, effort is available as was indicated by depth of research that was being con- in particular, the mechanisms of reacthe above description of the organiza- ducted as opposed to good development tions and bonding characteristics of tion by its director.

work. However, the pieces of C/Cs that the fibers in different mixtures of were shown to me appear to be of a phenolic matrices. Now this research is

shifting towards carbonaceous matrices.

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