| A Focused-Ion Beam (FIB) Nano-Fabrication and Characterization Facility |
22 NOV 2002 |
7 pages |
| Authors:
M. P. Harmer; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
 | This has been a most successful% project. The FIB has been purchased, installed and is now the most productive instrument in the Microscopy Center at Lehigh. Substantial research has been accomplished by the group of the principal investigator, but much research has been done by many other groups as well. Much of the work has involved the preparation of samples for examination in the transmission electron microscope (TEM) and scanning ... |
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| Grain Boundary Chemistry and Creep Resistance of Alumina |
MAR 2001 |
123 pages |
| Authors:
Martin P. Harmer; Helen M. Chan; Jeffrey M. Rickman; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| The Lehigh group has pioneered work on the role of segregating rare earth dopants on the grain boundary structure and tensile creep behavior of alumina. In an attempt to clarify the exact mechanism that controls creep behavior of the doped aluminas, various advanced characterization techniques have been applied including: secondary ion mass spectrometry (SIMS), scanning transmission electron microscopy (STEM), orientation image microscopy (OIM), x- ray absorption studies which include x-ray ... |
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| Multiphase Ceramics for Mechanical and Structural Reliability at Low and Elevated Temperatures |
10 AUG 94 |
246 pages |
| Authors:
Martin P. Harmer; Helen M. Chan; Gary A. Miller; A. M. Thompson; Junhong Zhao; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| AFOSR project 91-0126 was undertaken to develop a design approach for improving the high-temperature structural reliability (e.g., resistance to creep, fracture and grain growth) and room temperature mechanical reliability (e.g., flaw tolerance) of structural ceramics. Some of the major accomplishments of this work are highlighted. (MM) |
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| Multiphase Ceramics for Mechanical and Structural Reliability at Low and Elevated Temperatures |
30 JUN 94 |
206 pages |
| Authors:
M. P. Harmer; H. M. Chan; G. A. Miller; A. M. Thompson; J. Zhao; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| AFOSR project 91-0126 was undertaken to develop a design approach for improving the high-temperature structural reliability (e.g., resistance to creep, fracture and grain growth) and room temperature mechanical reliability (e.g., flaw tolerance) of structural ceramics. Some of the major accomplishments of this work are highlighted below: (1). Engineering of the grain boundary chemistry in alumina resulted in a lowering of the creep rate by over two orders of magnitude by ... |
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| Reaction Bonding and Mechanical Properties of Mullite/Silicon Carbide Composites. |
1994 |
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| Authors:
Suxing Wu; Nils Claussen; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
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 | Based on the RBAO technology, low-shrinkage mullite/SiC/Al2O3/ZrO2 composites were fabricated. A powder mixture of 40 vol% Al, 30 vol% Al2O3, and 30 vol% SiC was attrition milled in acetone with TZP balls which introduced a substantial ZrO2 wear debris into the mixture. The precursor powder was isopressed at 300-900 MPa and heat-treated in air by two different cycles resulting in various phase ratios in the final products. During heating, Al ... |
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| Processing of Novel Nanoparticle Dispersion Strengthened Ceramics for Improved Mechanical Performance |
14 DEC 93 |
65 pages |
| Authors:
Helen M. Chan; Martin P. Harmer; M. Thompson; J. Fang; I. Chou; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| Results from a previous study carried out by the Lehigh group demonstrated A12O3:SiC nanocomposites exhibited superior mechanical behavior relative to single phase alumina only when the samples had been annealed (2 h at 1300 deg C in argon) subsequent to industrial machining. These results were rationalized by postulating that on annealing of the machined specimens: (a) The extent of healing of grinding induced flaws is more significant in the nanocomposite ... |
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| NextelTM/siC Composites Fabricated Using Forced Chemical Vapor Infiltration |
93 |
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| Authors:
B. L. Weaver; R. A. Lowden; J. C. Mclaughlin; D. P. Stinton; T. M. Besmann; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
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| Oxide fiber-reinforced silicon carbide matrix composites were fabricated employing the forced-flow, thermal gradient chemical vapor infiltration (FCVI) process. Nextel TM fibers of varying composition were incorporated into the SiC matrix and the influence of fiber composition on densification was examined. Composites were prepared to investigate the effectiveness of each Nextel(TM) fiber as a reinforcement for the given matrix. A carbon interface coating was used for the baseline materials, however, alternate ... |
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| Processing of Novel Nanoparticle Dispersion Strengthened Ceramics for Improved Mechanical Performance |
14 DEC 92 |
106 pages |
| Authors:
Helen M. Chan; Martin P. Harmer; Gary A. Miller; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| Nanocomposites have continued to show promise both as structural ceramic materials and as ideal systems in which to design multiphase microstructures. This report focuses on successful techniques for fabricating A1203/SiC nanocomposites, the strengthening obtained by the addition of sub- micron SiC particles to Al203, and the technological advantages of the nanocomposite. Some of the most significant conclusions of this work are: (1) A technique has been developed to reproducibly fabricate ... |
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| Long Term Stability in Thin Film Ferroelectric Memories |
29 SEP 92 |
36 pages |
| Authors:
D. M. Smyth; M. P. Harmer; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| The mechanism and control of the fatigue of remanent polarization in thin film ferroelectric memories is being investigated. The predicted detrimental effect of acceptor-dopants and beneficial effect of donor-dopants has been confirmed in thinned samples of BaTi03. A similar but reduced effect has been observed in thin films of PZT, and the possible effect of PbO-loss on reducing the beneficial effect of donor dopants is being investigated. It has become ... |
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| Nanostructure, Defect Chemistry and Properties of Relaxor Ferroelectrics |
01 FEB 92 |
182 pages |
| Authors:
M. P. Harmer; D. M. Smyth; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| This research focused on cation ordering, defect chemistry, and dielectric properties of the BaTiO3-Ba(Zn1/3Nb2/3)O3 (BZN) system. The latter compound was chosen as an analog of the PbO-based relaxor ferroelectrics to avoid the severe experimental restrictions caused by the volatility and reducibility of PbO. Two types of ordering of the Zn and Nb content of BZN were observed; a 1:1 (alternate layer) type that represents a local compositional change and charge ... |
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| Mechanical properties of Interpenetrating Microstructures: The Al2O3/c- ZrO2 System |
92 |
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| Authors:
Jonathan D. French; Helen M. Chan; Martin P. Harmer; Gary A. Miller; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
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| Composites of Al2O3 (A) and cubic ZrO2 (Z) (8 mol% Y2O3) (with c-ZrO2 volume fractions ranging from 0 to 1) were fabricated by pressureless sintering of mechanically mixed powders. The microstructures of the AZ composites were duplex, with the grains of both phases exhibiting similar size. Room- temperature mechanical properties including Young's modulus (determined from elastic wave velocity measurements), strength and toughness (by indentation- strength-in bending), and Vickers microhardness were ... |
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| Unique Opportunities for Microstructural Engineering With Duplex and Laminar Ceramic Composites |
92 |
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| Authors:
Martin P. Harmer; Helen M. Chan; Gary A. Miller; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| Duplex (two-phase) microstructures and laminar composites offer some unique opportunities for improving the room-temperature mechanical reliability (e.g., flaw tolerance) and the high-temperature microstructural stability (e.g., resistance to grain growth and creep damage) of structural ceramic materials. Examples illustrating the approach to designing novel multiphase microstructures and laminar composites with enhanced structural reliability are given. These are based on current work on various alumina-based ceramics as well as zirconia- , silicon ... |
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| Design of a Laminated Ceramic Composite for Improved Strength and Toughness |
92 |
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| Authors:
Charles J. Russo; Martin P. Harmer; Helen M. Chan; Gary A. Miller; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
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| Adding aluminum titanate to alumina can result in dramatic improvements in toughness and R-curve properties. However, the improved toughness is offset by a significant reduction in strength at small sizes. This problem can be overcome through the use of a laminated composite construction. By placing a thin layer of high-strength material on the surface of a high- toughness body, the toughness and flaw tolerance of the body material can be ... |
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| Effect of Boron Addition on Recrystallization and Grain Growth in Ni3Al Polycrystals |
91 |
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| Authors:
B. Zhou; S. L. Yu; Y. T. Chou; C. T. Liu; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
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| An investigation of the recrystallization and grain growth kinetics in pure and B-doped Ni3Al polycrystals was carried out from 850 to 1000 C; the recrystallization processes were similar in character and in magnitude at 16.7% deformation; the activation energy of recrystallization for B-doped alloy (488KJ/mol) was greater than that of the B-free alloy (476 KJ/mol); a slow growth due to long- range ordering was shown by the grain growth kinetics ... |
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| Ionic Transport in LiNbO3 |
91 |
|
| Authors:
Apurva Mehta; Edward K. Chang; Donald M. Smyth; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
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| The high temperature equilibrium conductivity (950 C-1050 C) of congruent LiNbO3 can be resolved into two components: an electronic portion that is dependent on the oxygen partial pressure and an ionic portion that is pressure independent. It is shown that the two components can be obtained from an analysis of the total equilibrium conductivity measured as a function of oxygen partial pressure. The ionic transport number (fractional ionic conductivity) thus ... |
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| Strength and Toughness of Tailored Ceramic Microstructures |
30 DEC 90 |
127 pages |
| Authors:
M. P. Harmer; H. M. Chan; G. A. Miller; J. D. French; C. J. Russo; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| AFOSR project 87-0396 was undertaken to develop a detailed understanding of the link between microstructural variables and the strength and toughness of ceramic materials. A major emphasis of this effort has been developing approaches for producing multiphase ceramic microstructures with enhanced reliability i.e. elevated temperature microstructural stability and damage tolerance and/or room temperature flaw tolerance. Improvements in elevated temperature damage tolerance depend upon having a dual phase interconnected microstructure with ... |
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| Final Report on Office of Naval Research Contract No. N00014-84-K-0508 with Lehigh University |
14 OCT 90 |
2 pages |
| Authors:
M. C. Chang; J. J. Fay; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| A group contribution theory was developed to describe the area under the loss modulus-temperature peak, LA, in the glass transition region of homopolymers and single-glass transition statistical copolymers and related compositions. Within wide limits, each chemical group on the polymer was found to contribute a definite proportion of the area. Groups directly associated with the backbone chain contribute the most to damping, while long side chains actually are detrimental. Deviations ... |
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| Loss Modulus and Damping Behavior of Poly(vinyl methyl ether)-Polystyrene Blends and IPN's (Interpenetrating Polymer Networks), |
NOV 1989 |
|
| Authors:
J. J. Fay; C. J. Murphy; D. A. Thomas; L. H. Sperling; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| The miscibility of poly(vinyl methyl ether) PVME) and polystyrene (PS) IPNs was examined by dynamic mechanical spectroscopy (DMS) and differential scanning calorimetry. DSC indicates an increase in the breadth of the glass transition region for midrange compositions in linear blends and IPNs. Similarly, DMS data shows a narrow glass transition region for a 70/30 weight composition PVME/PS IPN and increasingly broader regions for 50/50 and 30/70 PVME/PS IPNs. The broad ... |
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| Multiple Endotherm Melting Behavior in Relation to the Morphology of Poly(3,3-bis(ethoxymethyl oxetane) |
22 JAN 89 |
37 pages |
| Authors:
J. J. Fay; C. J. Murphy; L. H. Sperling; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| Two crystalline melting peaks have been observed by differential scanning calorimetry for low molecular weight poly(3,3-bis- (ethoxymethyl) oxetane), polyBEMO, whereas only one melting peak has been observed for samples of higher molecular weight. Crystallization of low mol. wt. samples at large supercoolings produces the lower melting form, while low supercooling or annealing favors the higher melting species. Enthalpy of fusion values obtained by DSC for a multiple melting endotherm sample ... |
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| Electrical Degradation in Ceramic Dielectrics |
09 SEP 88 |
90 pages |
| Authors:
Martin P. Harmer; Donald M. Smyth; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| This report describes a continuation of an investigation of the mechanism of electrical degradation of ceramic dielectrics based on BaTiO3. The emphasis has been on the application of defect chemistry and electron microscopy in order to correlate degradation behavior with compositional and microstructural effects. The report is in four parts that deal with 1) an explanation for the earlier observation that samples that had been densified in a vacuum hot-press ... |
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| Nanostructure and Defect Chemistry of Relaxor Ferro electrics |
31 JUL 88 |
144 pages |
| Authors:
Martin P. Harmer; Donald M. Smyth; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| This report describes an investigation of the microstructure, microchemistry, and dielectric properties of relaxor ferroelectrics and structurally related compounds. The emphasis has been on the use of transmission electron microscopy to correlate changes in the composition and processing conditions with changes in microstructure and properties. The report is in three parts that dealt with 1 cation-ordering and microchemical domains in Pb(Sc1/ 2Ta1/2)3 (PST), undoped and La/Na-doped Pb(Mg1/3Nb2/3)3 (PMN) and Ba(Zn1/3Nb2/3) ... |
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| Fatigue Crack Propagation in Crystalline Polymers and Composites |
AUG 86 |
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| Authors:
John A. Manson; R. W. Hertzberg; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
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| As polymers are used to an increasing extent in load-bearing applications, often under cyclic or repetitive loads, an understanding of fatigue behavior is important. Since all polymers contain flaws that may, under appropriate conditions, develop into catastrophic cracks, the fatigue crack propagation (FCP) response is of particular interest to the engineer. The role of polymer structure and composition in the kinetics and energetics of FCP is, in turn, of fundamental ... |
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| Rare Earth Additions to BaTiO3 |
86 |
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| Authors:
K. Takada; E. Chang; D. M. Smyth; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| The incorporation of trivalent rare earth ions into BaTiO3 has been studied as a function of the Ba/Ti ratio. There is a gradual shift in the site occupied as a function of the ionic radius of the rare earth. The larger ions predominantly occupy the Ba sites and give donor-doped behavior, while the smaller ions prefer the Ti sites and confer acceptor-doped behavior. The Ba/Ti ratio has a significant effect ... |
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| Degradation Mechanisms in Ceramic Dielectrics |
AUG 84 |
|
| Authors:
D. M. Smyth; M. P. Harmer; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| This program is designed to identify the mechanisms that lead to leakage current degradation in BaTiO3-based dielectrics subjected to voltage- temperature stress, and to determine those factors that contribute to stability against such degradation. During the first year, it was confirmed that BaO-rich and donor-doped compositions are particularly stable, and that grain-size is a relatively unimportant parameter. During the second year of investigation, the microstructures of a BaO-rich and donor-doped ... |
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| Characterization of Block Copolymers Based on Poly(3,3 - bis(ethoxymethyl)oxetane) and Other Novel Polyethers |
04 MAY 1984 |
|
| Authors:
K. E. Hardenstine; C. J. Murphy; R. B. Jones; L. H. Sperling; G. E. Manser; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| The present study involves crystalline block copolymers based on poly(3,3-bis(ethoxymethyl)oxetane, polyBEMO, and random copolymers based on other either forming monomers. The objective of the work is to generate a block copolymer consisting of crystallizable polyether end blocks based on poly(BEMO) and an amorphous rubbery center block based on the polyether random copolymers. This paper will examine the interrelationships among glass and melting transition behavior, viscoelastic characteristics, tensile properties, and morphological ... |
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| Composition and Electrical Property Relationships in Polycrystalline Inorganic Materials |
01 FEB 1983 |
|
| Authors:
Donald M. Smyth; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| The goal of this program is to establish the defect chemistry of compounds whose applicability depends on the types and amounts of ionic and electronic defects. Attention was focused in this project on LiNbO3, a material being studied for a variety of electro-optic device applications. The main experimental approach was the measurement of the equilibrium electrical conductivity of LiNbO3 single crystals as a function of temperature (900-1100 C) , oxygen ... |
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| Fatigue Crack Propagation in Crystalline Polymers: Effect of Moisture in Nylon 66. |
28 DEC 1978 |
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| Authors:
P. E. Bretz; R. W. Hertzberg; J. A. Manson; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
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| As part of a study of the effects of crystallinity on fatigue crack propagation (FCP) behavior in crystalline polymers, the FCP response of nylon 66 was examined as a function of both stress intensity factor range (delta K) and water content. It was found that FCP rates were exponential functions of delta K, as expected. However, the FCP rates at constant delta K decreased as the water content was increased ... |
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| Discussion of 'A Model of Fatigue Crack Growth in Polymers'. |
28 DEC 1978 |
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| Authors:
Richard W. Hertzberg; Michael D. Skibo; John A. Manson; J. K. Donald; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
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| A model was previously proposed by Hertzberg, Skibo, and Manson to account for the sensitivity of fatigue crack growth rates to frequency. The model was based on the hypothesis that the mechanical Beta transition controls the fatigue deformation and on the use of time-temperature relationships to determine the match between the Beta transition frequency and temperature and the frequency and temperature of the test. An alternate model was recently proposed ... |
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| Fatigue Crack Propagation in Polymeric Materials. |
NOV 1978 |
|
| Authors:
Richard W. Hertzberg; John A. Manson; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| This report summarizes the results of a research program to bring polymer science and fracture mechanics technologies to bear on the subject of polymer fatigue. The first major thrust area concerned an analysis of fatigue fracture micromechanisms in amorphous engineering plastics. (Author) |
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| Morphology and Mechanical Behavior of Isomeric Graft Copolymers and Interpenetrating Polymer Networks. |
30 SEP 1978 |
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| Authors:
L. H. Sperling; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| The major accomplishments encompass four areas of research: (1) Controlled Grafting of Simultaneous Interpenetrating Polymer Networks. This research, which elucidated the relationship between polymer 1/polymer 2 compatibility and deliverately introduced graft sites, has now been accepted for publication by Polymer Science and Engineering. From an engineering point of view, the controlled morphology produced using epoxy/acrylic combinations yielded very tough, novel plastics. (2) Novel Staining Techniques for Saturated Two-Phased Polymers. Up ... |
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| Investigative Study on the Feasibility of Utilizing Fluorinated Ethylene Propylene Elastomers as Protective Mask Faceblank Materials. |
MAY 1978 |
|
| Authors:
L. H. Sperling; D. A. Thomas; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| This paper demonstrates the feasibility of obtaining a tough, transparent crosslinked fluorocarbon elastomer with reduced creep. The linear material exhibits creep and tackiness but is relatively clear. Existing vulcanizing recipes yield opaque, crosslinked materials. Polymerization is accomplished via high energy radiation. The linear fluorocarbon is physically bound up with the crosslinked network formed by the polymerized monomer, producing a semiinterpenetrating polymer network (IPN) of the second kind. The optimum conditions ... |
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| ENVIRONMENTAL ASSISTED FATIGUE CRACK PROPAGATION IN 3003-0 ALUMINUM |
AUG 77 |
|
| Authors:
R. Roberts; J. C. Tafuri; K. Wnek; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| The rate of propagation of fatigue cracks as a function of test environment was examined in 3.18 mm (0.125 inch) thick specimens of 3003-0 aluminum alloy. This alloy finds wide application in the production of brazed aluminum heat exchangers for cryogenic service. Tests were run in humid air, dry argon, and deionized water at room temperature and cyclic frequencies of 1 Hz, 10 Hz, and 20 Hz at R=0.1. Tests ... |
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| Influence of Crosslinking on the Mechanical Properties of High T(G) Polymers |
JUL 1977 |
146 pages |
| Authors:
John A. Manson; Leslie H. Sperling; Soojaa L. Kim; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| A study was conducted on the effects of crosslinking on the mechanical properties of high-T(g) polymers, with emphasis on the role of average crosslink density and on variations in the distribution of chain lengths between crosslinks. Two model systems were used: one based on the use of polystyrene/polystyrene interpenetrating polymer networks (Millar networks), and the other based on the use of bisphenol-A-type epoxy/methylene dianiline resins synthesized to provide controlled variations ... |
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| FRACTURE BEHAVIOR OF A36 BRIDGE STEELS |
APR 77 |
|
| Authors:
R. Roberts; G. V. Krishna; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| the fracture toughness behavior of three heats of a36 steel was examined in terms of cvn response and k(sub ic) measurements at an intermediate rate of loading (i.e., one second rise time to failure). these results were contrasted with current aashto toughness requirements and heat or ''h'' testing frequency. it was concluded that ''h'' frequency testing could prove to be inadequate for fracture critical details. in such instances each piece ... |
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| Influence of Crosslinking on the Mechanical Properties of High TG Polymers |
JUL 1976 |
102 pages |
| Authors:
John A. Manson; Leslie H. Sperling; Soojaa L. Kim; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| Research was begun on the effects of crosslinking on the mechanical properties of high-Tg polymers, with particular emphasis on the role of crosslink density, variations in the distribution of crosslink segment lengths, and the role of network imperfections. Two systems were selected: one based on the use of the Bamford synthesis to provide model, well defined networks, and the other based on the use of bisphenol-A-type epoxy/methylene dianiline resins synthesized ... |
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| Applied Research and Engineering on Coatings for Noise Damping. |
JAN 1975 |
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| Authors:
L. H. Sperling; D. A. Thomas; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| The report describes research and development studies on a broad-temperature damping system known as 'Silent Paint'. Materials capable of effective damping over the temperature range of -20C to +60C were developed and optimized. Research was undertaken on both acrylic and poly(vinyl chloride) based damping materials. Damping theory and polymer structure are discussed in relation to performance. |
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| INTERPRETATION OF HOT PRESSING KINETICS BY DENSIFICATION MAPPING TECHNIQUES |
74 |
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| Authors:
M. R. Notis; R. H. Smoak; V. Krishnamachari; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
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| A Latex IPN (Interpenetrating Polymer Network) Coating System for Damping Noise and Vibrations over a Broad Temperature Range |
JAN 1973 |
32 pages |
| Authors:
L. H. Sperling; Tai-Woo Chiu; R. G. Gramlich; D. A. Thomas; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| Based on the principles of constrained layer damping, 'Silent Paint' is a two-layer coating system capable of attenuating noise and vibration over a broad temperature range. The damping undercoat layer is composed primarily of a methacrylic/acrylic semi-compatible inter-penetrating polymer network (IPN) in latex form, with thickeners and preservative added. The constraining overcoat layer is based on a reinforced epoxy resin, and exhibits great stiffness. The total system, exhibiting significant damping ... |
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| Photocurrent Spectroscopy in Thin Film Insulators: Voltage Dependence of the External Circuit Current, |
1973 |
|
| Authors:
D. J. DiMaria; F. J. Feigl; LEHIGH UNIV BETHLEHEM PA MATERIALS RESEARCH CENTER
|
| An analytical model for trapping state photodepopulation measurements in conductor-thin film insulator-conductor structures is presented. The external circuit current dependence on applied voltage is determined, and it is shown that moments of the spatial distribution of trapped charge in the insulator can be extracted from collected charge vs. applied field characteristic curves. The photodepopulation technique is compared with more widely used differential capacitance and photoemission current techniques. |
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