A review, nine publications, and the results, on the preparation and characterization of thin films for electroluminescent (EL) applications, are discussed. Atomic layer epitaxy (ALE) is used to grow the ZnS, CaS, SrS, and BaS films and to dope them with divalent manganese (ZnS) and trivalent rare earths. The starting materials for the thin film growth are zinc chloride or acetate, alkaline earth and rare earth complexes of 2,2,6,6-tetramethyl 3,5-heptanedione and hydrogen sulfide. The films are characterized by measuring their photoluminescence spectra, X-ray diffraction patterns, and activator concentrations using methods based on X-ray fluorescence. In addition, electroreflectance, ellipsometric, Auger, secondary-ion mass spectrometry measurements and chemical analysis are used. The results indicate that good quality EL thin films can be grown by the ALE process. For the growth of zinc sulfide films from zinc acetate, the growth rates are relatively low. ESA N89-28614 Technische Univ., Delft (Netherlands). Some aspects related to peak tracking or peak recognition in high performance liquid chromatography (HPLC) are investigated. A number of possible alternative techniques, such as relative peak areas, dual wavelength ratios, and comparison of complete spectra, are applied. These applications indicate that a coelution of two or more components in a peak cluster presents one of the main problems. The use of peak tracking in early stages of the chromatographic optimization process, (characterizing components as basic, acidic, or neutral), allows for an efficient selection of optimization parameters. The number of actual experiments required during the optimization process is thus reduced. 26 METALLIC MATERIALS ESA Includes physical, chemical, and mechanical properties of metals, e.g., corrosion; and metallurgy. N89-28615# National Inst. of Standards and Technology, Gaithersburg, MD. Metallurgy Div. METALLURGICAL EVALUATION OF 17-4 PH STAINLESS STEEL CASTINGS George E. Hicho and John H. Smith May 1989 35 p Sponsored by Naval Ordnance Station, Indian Head, MD (PB89-193262; NISTIR-89/4075) Avail: NTIS HC A03/MF A01 CSCL 11F A metallurgical evaluation was conducted to determine if selected castings of 17-4 PH stainless steel used in head caps on missile weapon systems had been properly heat treated as required by SAE specification AMS-5355D. Optical metallographic analysis and hardness measurements were made on four samples of as-received castings and on selected samples that were homogenized, solution annealed and aged at various temperatures. Metallographic and hardness results indicate that the head caps identified as 5066, 5441, NIST 1, and 20 were not heat treated according to AMS specification 5355D, in particular to condition H1000, which refers to the aging temperature (1000 F). GRA (Contract DE-AC03-76SF-00098) (DE89-012991; LBL-27164; CONF-8904236-1; CONF-8906152-1) Avail: NTIS HC A02/MF A01 Alkanes are among the most chemically inert organic molecules. They are reactive toward a limited range of reagents, such as highly energetic free radicals and strongly electrophilic and oxidizing species. This low reactivity is a consequence of the C-H bond energies in most saturated hydrocarbons. These values range from 90 to 98 kcal/mole for primary and secondary C-H bonds; in methane, the main constituent of natural gas, the C-H bond energy is 104 kcal/mole. This makes methane one of the most common but least reactive organic molecules in nature. This report briefly discusses the search for metal complexes capable of undergoing the C-H oxidative addition process allowing alkane chemistry to be more selective than that available using free radical reagents. Compatibility with mixed gases containing S, O, and Cl is a critical requirement for high temperature alloys used in coal conversion and combustion applications. Comparative corrosion tests of Fe-25Cr-20Ni, Fe-18Cr-6Al, and Fe-9Cr-9Nb-6AI (wt percent) at 700 to 800 C in simulated coal gasification environment led to the development of Fe-Nb-Al alloys and testing of both Fe-Nb-Al and Fe3Al alloys. The niobium and aluminum content in the latter alloys ranged from 8 to 18 and 6 to 16 wt percent, respectively. The niobium addition was intended as a selective refractory sulfide former. Testing was carried out at 700 to 800 C in H2S-H2-H2O gas mixtures with relatively low oxygen activities (less than or equal to 10(-22) atm) and high sulfur activities (greater than or equal to 10(-6) atm). Metallographic and chemical analyses of the corrosion product scales and the underlying alloy were performed to determine the role of the respective metallic elements on sulfidation/oxidation processes. DOE N89-28618# Massachusetts Inst. of Tech., Cambridge. Dept. of Kenneth C. Russell and F. A. Garner (Pacific Northwest Labs., (DE89-014454; PNL-SA-16211; CONF-8902117-1) Avail: NTIS HC A03/MF A01 Many studies have suggested that Fe-Ni and Fe-Ni-Cr alloys of ca. 35 at. percent Ni are susceptible to decomposition into two FCC (face centered cubic) phases. We herein model the kinetics and thermodynamics of spinodal decomposition, nucleation, growth, and coarsening of these alloys. Prediction of the scale of a microstructure formed by growth or coarsening may be done with some confidence. The absence of a model for surface energy and gradient energy in systems with negative departure from ideality reduce us to little more than guesses for the kinetics of nucleation and of spinodal decomposition. We combine our calculations with those of others and studies of terrestrial and celestial N89-28619# California Univ., Berkeley. Lawrence Berkeley Lab. National Center for Electron Microscopy. Presented FUNDAMENTAL STUDIES OF GRAIN BOUNDARY STRUCTURE AND PROPERTIES IN ICB ALUMINUM K. H. Westmacott and U. Dahmen May 1989 18 p at the 12th Symposium on lon Sources and lon-Assisted Technology, Tokyo, Japan, 5 Jun. 1989 (Contract DE-AC03-76SF-00098) (DE89-014884; LBL-27187; CONF-8906157-2) Avail: NTIS HC A03/MF A01 Thin films prepared by the lonized-Cluster-Beam (ICB) technique, pioneered at Kyoto University, are of great interest for both their fundamental structure and properties and their potential for practical applications. At Berkeley, a research program was initiated, in collaboration with professor Yamada and his colleagues at Kyoto University, to investigate a different aspect of ICB films. The unique bicrystal microstructure that forms with some thin film/substrate combinations are exploited to conduct a fundamental investigation of grain boundary structure and properties. Initially, the studies are being carried out on aluminum bicrystal films formed by deposition on a 100-silicon single crystal substrate. Two types of Transmission Electron Microscopy (TEM) experiments are reported. High resolution imaging of specific grain boundary segments is performed on a second HVEM capable of resolving the position of atom columns in the core regions of a grain boundary. Complementary information obtained by the two techniques helps the understanding of the structure and properties of grain boundaries as well as learn more about ICB thin films. The results of preliminary high resolution observations of silver DOE clusters dispersed on a carbon grid are given. N89-28620# Pacific Northwest Labs., Richland, WA. FREEZE-DRIED TUNGSTEN HEAVY ALLOYS 19 p Presented at G. D. White and W. E. Gurwell Mar. 1989 the Powder Metallurgy Conference, San Diego, CA, 11-14 Jun. 1989 (Contract DE-AC06-76RL-01830) (DE89-014933; PNL-SA-16378; CONF-8906119-2) Avail: NTIS HC A03/MF A01 Tungsten heavy alloy powders were produced from freeze-dried aqueous solutions of ammonium metatungstate and, primarily, sulfates of Ni and Fe. The freeze-dried salts were calcined and hydrogen reduced to form very fine, homogenous, low-density, W heavy alloy powders having a coral-like structure with elements of approximately 0.1 micrometer in diameter. The powders yield high green strength and sinterability. Tungsten heavy alloy powders of 70, 90, and 97 percent W were prepared by freeze drying, compacted, and solid-state (SS) sintered to full density at temperatures as low as 1200 C and also at conventional liquid-phase (LP) sintering temperatures. Solid-state sintered microstructures contained polygonal W grains with high contiguity; the matrix did not coat and separate the W grains to form low-contiguity, high-ductility structures. Liquid-phase sintered microstructures were very conventional in appearance, having W spheroids of low contiguity. All of these materials were found to be brittle. High levels of residual S accompanied by segregation of the S to all the microstructural interfaces are principally responsible for the brittleness; problems with S could be eliminated by using Fe and Ni nitrates rather than the sulfates. Unusually high hardness, approaching 48 HRC, was obtained from sintering at 1130 C. As-sintered hardness decreases as grain size increases with sintering temperature during SS sintering and with time during LP sintering. N89-28621* DOE National Aeronautics and Space Administration. Langley Research Center, Hampton, VA. ALUMINUM ALLOY Patent Linda B. Blackburn, inventor (to NASA) and Edgar A. Starke, Jr., inventor (to NASA) (Virginia Univ., Charlottesville.) 11 Apr. 1989 (NASA-Case-LAR-13924-1-CU; US-Patent-4,820,488; US-Patent-Appl-SN-172102; US-Patent-Class-420-529; This invention relates to aluminum alloys, particularly to aluminum-copper-lithium alloys containing at least about 0.1 percent by weight of indium as an essential component, which are suitable for applications in aircraft and aerospace vehicles. At least about 0.1 percent by weight of indium is added as an essential component to an alloy which precipitates a T1 phase (Al2CuLi). This addition enhances the nucleation of the precipitate T1 phase, producing a microstructure which provides excellent strength as indicated by Rockwell hardness values and confirmed by standard tensile tests. Official Gazette of the U.S. Patent and Trademark Office N89-28622# Army Lab. Command, Watertown, MA. Material Technology Lab. OXIDATION AND HOT CORROSION OF SOME ADVANCED SUPERALLOYS AT 1300F TO 2000F (740C TO 1093C) Final Report Milton Levy, Robert M. Huie, and Fred Pettit (Pittsburgh Univ., PA.) Apr. 1989 27 p (DA Proj. 1L1-62105-AH-84) (AD-A209353; MTL-TR-89-26) Avail: NTIS HC A03/MF A01 CSCL 11/6 The cyclic oxidation resistance and the hot corrosion resistance of three single crystal nickel-base superalloys and DS MAR M 200 are compared. The comparison is made by using burner rig oxidation tests at 2000 F (1093 C), and tube furnace oxidation and hot corrosion tests at 2000 F (1093 C), 1650 F (900 C), and 1300 F (704 C). The rig tests and the tube furnace tests produce similar results with the single crystal alloys being more oxidation resistant than DS MAR M 200. A significant difference between the hot corrosion resistance of these alloys was not observed. All four alloys were extremely susceptible to hot corrosion induced by a liquid deposit. GRA Army Lab. Command, Watertown, MA. Material N89-28623# The Bauschinger effect may be defined as a phenomenon by which plastic deformation of a polycrystalline material causes a reduction in yield strength upon reloading in a direction opposite to the original direction. This characteristic of plastic flow results from the inhomogeneity of plastic flow on the microscopic level. In this report, the Bauschinger effect in 6-6-2 titanium alloy is evaluated and an illustration is given to demonstrate its importance in the design and reliability of the Army's advanced artillery projectiles. The tension-compression specimens, fabricated from the recovered projectiles, are loaded to compression to a specified plastic range, followed by tension after unloading. The experimental results indicate that the original yield strength of the material is greatly reduced due to reverse loading. N89-28624# GRA Army Lab. Command, White Sands Missile Range, NM. Material Technology Lab. AN INVESTIGATION OF THE WORKABILITY OF AI-8.5 18 P Aluminum-magnesium alloys containing greater than 5 wt percent magnesium are high strength, lightweight alloys which show potential to be utilized by the Army in armor applications. A problem encountered thus far with these high strength alloys is some (Contract N00014-87-K-0738) (AD-A209602; TR-3) Avail: NTIS HC A02/MF A01 CSCL 11/2 A comprehensive investigation into the processing of ZnS, which involve synthesis and characterization of submicron powders and their processing at elevated temperature to produce dense ceramic parts, was the main objective of this investigation. Thermomechanical characterization of the dense polycrystalline ceramics is also an integral part of such a study, and is underway. Zinc sulfide powders with submicron particle size were prepared by homogeneous precipitation from acidic zinc solutions by aging with thioacetamide at elevated temperatures. Monosize, polycrystalline particles having 0.35 micrometer diameter were obtained. Sulfide ion generation rate in solution depended on temperature, pH and initial thioacetamide concentration. The rate of sulfide ion generation, in turn, influenced precipitation kinetics and particle morphology. The types of supporting anions in solution also influenced the morphology of the particles produced. Monosize powders were hot pressed for various time, temperature and pressure combinations. Compacts achieved near-theoretical density in less than 30 minutes at temperatures 850 to 900 C and applied pressures of about 70 to 105 MPa. The dominant densification mechanisms were identified at various stages of the process. Steven R. Thompson Nov. 1988 31 p (AD-A208107; AFWAL-TR-88-4254) Avail: NTIS HC A03/MF A01 CSCL 11/6 In a previous effort the fatigue crack growth rate characteristics of Ti-6A-4V were obtained from two forgings and compared to reference data in the literature. Both the test data and the reference data were from forgings identified as being in the beta-quenched condition but the fatigue crack growth rates were different. An understanding is provided of the cause of the difference of examining the microstructure and developing additional fatigue crack growth rate (FCGR) data for the six inch thick forgings used to develop the test data. The reference data was developed on two inch thick forgings. GRA and the matrix above what they exhibited in stand-alone tests. The effect of fiber orientation and matrix alloy composition on the fiber/matrix interface were also evaluated. Small alloying additions of zirconium and tungsten to the niobium matrix affected the creep resistance of the composites only slightly. A decrease in the creep resistance of the composite with increasing zirconium content in the matrix was ascribed to an increase in the diffusion rate of the fiber/matrix interdiffusion reaction, and a slight increase in the creep resistance of the composite was observed with an addition of 9 w percent tungsten to the matrix. In addition, Kirkendall void formation was observed at the fiber/matrix interface; the void distribution differed depending on the fiber orientation relative to the stress axis. Author N89-28628# National Aeronautical Lab., Bangalore (India). PRESSURE INDUCED ANOMALY AT TC IN Fe78 Mo2 B20 The effect of pressure on the nature of the anomaly near the curie temperature (T sub c) in the amorphous ferromagnetic metallic glass Fe78M02B20 was investigated. The continuous variation in resistivity near T sub c at ambient pressure changes into a discontinuous type of transition at higher pressures. Thermoelectric Power exhibits a marked anomaly near T sub cat ambient pressure. Author N89-28630 British Aerospace Public Ltd. Co., Preston (England). Aircraft Group Warton Div. IN-SITU ANODISING OF ALUMINIUM ALLOYS C. Brindle Aug. 1988 19 p (BAe/WMD/AR/GEN/00666; ETN-89-95221) Avail: British Aerospace Public Ltd. Co., Preston Lancs PR4 1AX, United Kingdom The results of the work on aluminium alloys, for the assessment of local anodizing process or treatment, are reported. The comparison between the brush processes with and without chromic acid pickle, is made. The investigation of brush anodizing for 7000 series of aluminum alloys shows that the selectrons Alorode process provides corrosion protection as good as a conventional chromic acid anodizing. The extention of this process for use on other alloys indicates that process improvement is needed. ESA N89-28631 National Physical Lab., Teddington (England). Div. of Materials Applications. EFFECT OF TEMPERATURE AND H2S CONTENT ON THE The cracking resistance of a 13 percent chromium martensitic steel (used for oil production tubing) was determined, applying the slow strain rate technique, as a function of the temperature (23 C to 80 C) and H2S content of acidified NaCl. It is observed that a temperature increase of the solution leads to an increase in time-to-failure (for H2S concentrations less than 100 parts per million). For constant sub-surface hydrogen content an increase in time to failure, associated with reduced occupancy of reversible traps at high temperatures, is revealed. The predominant factor determining cracking is shown to be the fractional occupancy of reversible trap sites. A correlation was identified between relative time-to-failure and fractional occupancy of traps irrespective of whether the latter is obtained by varying temperature, H2S content or pH (less than or equal to 3.6). ESA N89-28632# Helsinki Univ. of Technology, Espoo (Finland). Lab. of Metal Working and Heat Treatment. THE INFLUENCE OF STRUCTURE AND ALLOYING ON THE COLD-FORMABILITY OF FERRITIC STEELS AND THE UTILITY OF UNIAXIAL TENSILE TESTING IN ITS ASSESSMENT Ph.D. Thesis Vesa Ollilainen 1988 104 p Sponsored by the Academy of Finland and the Ovako Steel Oy Ab (ISBN-952-90044-3-5; ETN-89-95180) Avail: NTIS HC A06/MF A01 The dependence of the cold-formability of ferritic steels on their structure and alloying is studied. The assessment of cold-formability is based on material parameters. Attention is paid to the effects of chromium on the yield stress. The applicability of material parameters describing stress-strain relationship, especially strain-hardening, and those predicting ductility in terms of formability maps, is evaluated. The utility of the uniaxial tensile testing in the assessment of cold-formability is discused. It is shown that: chromium affects the yield stress of ferritic irons through three mechanisms; double eta behavior is favored by a coarse grain size and by a fine distribution of a non-deformable NbC particles; the use of eta value as a measure of the rate of strain hardening is misleading; an entire formability map for ferritic sheet steels may be predicted from parameters determined in a uniaxial tensile test; and that by lowering the yield and flow stress, chromium alloying and a coarse grain size the cold-formability of ferritic steels, is improved. 27 NONMETALLIC MATERIALS ESA (Grant NA86AA-D-SG089; MIT Proj. A-1) 26 P Workshop held in (PB89-182950; MITSG-89-7; OPPORTUNITY-BRIEF-54) Avail: NTIS HC A03/MF A01 CSCL 11C Polymers produced by marine plants and animals have been long valued as food and industrial ingredients. Recent developments in biotechnology, enzyme technology, and food and biochemical engineering have lead to new applications for these marine biopolymers. In the biomedical field, research is under way to develop a process for the encapsulation of mammalian cells prior to a transplantation operation. Within the food industry, marine biopolymers have always played an important role, such as stabilizers, and gelling ingredients, etc. Several research projects were undertaken to devise new applications for marine biopolymers in the food industry. These include: chitosan fibers, films and globules; encapsulation of biologicals with chitosan; fluorescence sensor for food and oil deterioration; stabilization of alcohol oxidase by entrapment in alginate beads; complex marine biopolymer coacervate capsules in plant technology; and, microencapsulated liposomes (the use of alginates for drug delivery systems). GRA N89-28634# Lehigh Univ., Bethlehem, PA. Dept. of Chemistry. (Contract DE-FG02-86ER-13612) (DE89-013310; CONF-890792-1) Avail: NTIS HC A02/MF A01 The deposition of carbon on alumina and on catalysts, in which alumina was the support for platinum and rhenium, was followed by simultaneously weighing the total deposit and observing the infrared spectra. At total carbon deposit levels of 1 percent or less, produced by exposure to acetylene at 525 K or ethylene at 625 K, bands were observed near 1580 and 1470 cm sup minus 1. Isotopic labeling with oxygen-18 and deuterium shows that these bands are attributable to the asymmetric and symmetric stretching vibrations of a carbon-oxygen species similar to a carboxylate ion. This species involves about one-sixth of the total carbon in deposits on alumina. Platinum does not markedly affect the total carbon or the fraction that is carboxylate. Rhenium does not affect the total carbon but it significantly lowers the carbon-oxygen species. Pretreatment of desulfurization catalysts with ammonia reduces the total carbon by about one-half and almost eliminates carboxylate formation. Carboxylates are not found in carbon deposits on silica. DOE N89-28635# Tulsa Univ., OK. METALLIC BONDING TO HIGH-TEMPERATURE Douglas C. Hague, V. A. Maroni, and John H. Meiser (Argonne (DE89-014668; CONF-8904238-1) Avail: NTIS HC A02/MF A01 Yttrium-barium-copper-oxide (123) superconducting ceramic pellets where obtained from J. P. Singh and K. C. Goretta at Argonne National Laboratory (ANL). The pellets were prepared in accordance with established methods. The pellets were then thermocompressively bonded by the methods of Meiser, et al. The resistivities of the samples were determined using a Keithley 181 Nanovoltmeter and a Keithley 227 Current Source. The resistances were taken over a range of 0.1 amp to 1 amp and were converted to interfacial resistivities. A simple tensile test was also applied to the samples to determine bond strengths. N89-28636# Oak Ridge National Lab., TN. MICROWAVE SINTERING OF CERAMICS DOE W. B. Snyder 1989 5 p Presented at the International Congress on Technology and Technology Exchange, New York, NY, 28 Jun. 1989 (Contract DE-AC05-84OR-21400) (DE89-014769; CONF-8906135-2) Avail: NTIS HC A02/MF A01 Successful adaptation of microwave heating to the densification of ceramic materials require a marriage of microwave and materials technologies. Using an interdisciplinary team of microwave and materials engineers, the ability to density ceramic materials over a wide range of temperatures was successfully demonstrated. Microstructural evolution during microwave sintering was found to be significantly different from that observed in conventional sintering. The results and those of others indicate that microwave sintering has the potential to fabricate components to near net shape with mechanical properties equivalent to hot pressed or hot isostatically pressed material. N89-28637# Chemistry. Harvard Univ., Cambridge, MA. DOE Dept. of MONOLAYERS OF 11-TRICHLOROSILYLUNDECYL THIOACETATE: A SYSTEM THAT PROMOTES ADHESION BETWEEN SILICON DIOXIDE AND EVAPORATED GOLD Interim Technical Report Stephen R. Wasserman, Hans Biebuyck, and George M. Whitesides May 1989 46 p Submitted for publication (Contract N00014-85-K-0898; NR Proj. 356-856) (AD-A208266; TR-16) Avail: NTIS HC A03/MF A01 CSCL 07/4 This chapter describes the use of sulfur-containing organic monolayers to improve the adhesion of gold to silicon substrates having a native silicon dioxide surface layer. Gold adheres to clean silicon, but not to silicon dioxide. The affinity of gold toward silicon dioxide can be improved by coating with chromium or titanium films or by adding interlayers containing fluoride salts. Bombardment of gold-covered silicon dioxide with electrons or heavy ions also enhances adhesion. Thin covalently-bonded alkylsiloxane films containing amines or epoxides improve the adherence of gold to glass. Here we demonstrate that covering a Silicon/Silicon dioxide substrate with a covalently attached organic monolayer film containing thiol groups (and possibly disulfides derived from them) or thioacetate groups improves the adhesion of gold to the substrate. N89-28638# Missouri Univ., Rolla. Dept. of Chemistry. CHARACTERIZATION OF SUBSTITUTED GRA PHENOL-FORMALDEHYDE RESINS USING SOLID-STATE CARBON-13 NMR Interim Report, Apr. 1988 - 22 May 1989 Frank D. Blum, Brijnaresh R. Sinha, and Daniel OConnor (Cardolite Corp., Newark, NJ.) 22 May 1989 15 p Revised Submitted for publication (Contract N00014-88-K-0109; NSF DMR-86-16789) Crosslinked substituted phenol formaldehyde resins were synthesized from cashew nut shell liquid, 3-n-pentadecylphenol and phenol with formaldehyde. The resulting resins were crosslinked and then investigated using carbon-13 NMR in the solid state using cross-polarization, magic angle spinning, and dipolar decoupling. Comparisons were made between the spectra of pure phenol-formaldehyde and modified phenol-formaldehyde resins and it was shown possible to distinguish between the resins. It was also shown that the proton-dephased spectrum gave better spectral resolution for the substituted compounds. In addition the solid carbon-13 technique verified that the degradation of the substituted phenolic resins occurs first with the degradation of the side chain in agreement with suggestions from earlier work. N89-28639# Engineering. GRA Stanford Univ., CA. Dept. of Chemical LITHOGRAPHY AND SPECTROSCOPY OF ULTRATHIN S. W. Kuan, P. S. Martin, L. L. Kosbar, C. W. Frank, and R. F. (AD-A208970) Avail: NTIS HC A03/MF A01 CSCL 20/12 Ultrathin (0.9 to 15.3 nm) poly (methyl methacrylate) (PMMA) and (30 to 40 nm) novolac/diazoquinone films prepared by the Langmuir-Blodgett (LB) technique were explored as high resolution electron beam resists and photoresists, respectively. One-eighth micron lines-and-spaces patterns were achieved in PMMA using the Perkin Elmer MEBESI pattern generation system as the exposure tool. The etch resistance of PMMA films with thicknesses greater than 4.5 nm is sufficient to allow patterning of chromium film suitable for photomask fabrication. One micron linesand-spaces patterns were fabricated by optical lithography in 30 nm thick novolac/diazoquinone films, and etched into 50 nm of chromium. Monolayer PMMA films containing 5 mol percent pyrenedodecanoic acid (PDA) is a probe were prepared by transfer to a quartz substrate at different surface pressures and characterized by fluorescence spectroscopy. The ratio of excimer to monomer emission intensity (le/lm) has a maximum value at 10 dyn/cm, which is suggestive of a structural rearrangement occurring in the Langmuir film at the surface pressure. GRA N89-28640# Connecticut Univ., Storrs. (AD-A209024; ARO-23793.3-MS) Avail: NTIS HC A02/MF Upon cooling, solutions of rigid-rod macromolecules often form gels. These can be further processed to form microcellular materials with very regular structure. A two-stage melting of the precursor gels has been tentatively associated with a bimodal structure found in the microcellular materials. GRA N89-28641# Northwestern Univ., Evanston, IL. (AD-A209036; ARO-22743.1-MS) Avail: NTIS HC A03/MF Radiothermoluminescence (RTL) involves irradiating a solid at low temperature (77K) with ionizing radiation and observing luminescence when heating the sample at a constant rate (10 K/min). Glow peaks are observed at characteristic temperatures which, for polymers, are diagnostic of the onset of thermally activated molecular motions. A scanning electron microscope (SEM) was modified to irradiate polymer samples with medium energy (5 to 30 keV) electrons. This SEM-RTL device is more convenient and reliable than other techniques which utilize remote radiation sources though information is confined to the near surface regions of the sample. In particular, the oxygen-free environment of the SEM-RTL experiment permitted observation of high temperature relaxations (up to 150 C or 423 K) for the first time in a number of thermoplastics. N89-28642# Dayton Univ., OH. Research Inst. Michael L. Drake Mar. 1989 289 p (AD-A209071; UDR-TR-88-122; AFWAL-TR-88-4248) Avail: NTIS HC A13/MF A01 CSCL 11/2 GRA Complex modulus data is presented for a total of 44 materials. The material types include polymers, enamels, and structural adhesives. The complex modulus data was obtained using the ASTM E-756 standard test. The complex modulus data set for each material given contains the following information: a full page reduced frequency nomogram (FRN), a half page RFN with a list of the modulus, loss factor, and alpha sub T equations and equation parameters used to fit the data. A plot of test frequency versus test temperature. A plot of material modulus versus test temperature. GRA N89-28643# Hughes Aircraft Co., El Segundo, CA. Electro-Optical and Data Systems Group. HIGH TEMPERATURE ADHESIVE SYSTEMS Final Report, 25 Sep. 1985 24 Apr. 1989 E. H. Catsiff, T. K. Dougherty, W. E. Elias, D. J. Vachon, G. Angsten, R. W. Seibold, W. G. Knauss, S. Shimabukuro, and K. M. Liechti (Texas Univ., Austin.) Apr. 1989 224 p (Contract N00014-85-C-0881) (AD-A209166; HAC-REF-F7896-F) Avail: NTIS HC A10/MF A01 CSCL 11/1 Projected requirements for future high-performance jet engine, missile, and fighter aircraft structures will necessitate extensive use of high temperature structural adhesives. For example, many advanced jet engine and tactical aircraft components will need to perform for hundreds of hours at 700 F (371 C) and above. For advanced air-to-air tactical missiles and air-launched stand-off missiles, composite airframe structures capable of maintaining strength for short periods (minutes) at 1000 F (538 C) and above will be needed. Other needs for adhesives capable of performing |