| Control of Polyimide Condensation Composite Processing |
MAR 94 |
122 pages |
| Authors:
John L. Kardos; Milorad P. Dudukovic; Babu Joseph; Jiri L. Vasat; D. H. Kim; WASHINGTON UNIV ST LOUIS MO
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 | AFR700B is a high temperature polyimide resin having the advantages of a high glass transition temperature (750 deg F) and superior thermo-oxidative stability, but the disadvantage of a volatile management problem. This study explored a new process simulation model, new sensing technology, and new concepts in process control in order to advance the state of processing science and to make the processing of AFR700B composite parts cost effective. The new ... |
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| Quasicrystalline and Related Crystalline Phases in a Rapidly Solidified 2024-2Li Aluminium Alloy |
91 |
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| Authors:
D. H. Kim; K. Chattopadhyay; B. Cantor; KOREA INST OF SCIENCE AND TECHNOLOGY SEOUL*
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 | TEM was used to study the formation and decomposition of quasicrystalline and crystalline phases in as-rapidly solidified and annealed AA 2024 containing 2% Li; microstructure of as-melt spun samples consisted of alpha-Al cells, containing small coherent delta prime-precipitates, and particles or continuous network of an icosahedral phase at the cell boundaries; intercellular particles of the icosahedral phase progressively coarsened and assumed more faceted shape after annealing at 300C; particles of ... |
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| Fatigue Crack Growth Behavior of a Continuous Alumina Fiber Reinforced Magnesium Alloy |
91 |
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| Authors:
D. H. Kim; E. J. Lavernia; J. C. Earthman; CALIFORNIA UNIV IRVINE DEPT OF MECHANICAL ENGINEERING
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| The effects of heat treatment on fatigue crack growth behavior were studied in a pressure infiltrated, continuously reinforced, magnesium-based composite (fp/ze41a). following an earlier tem investigation, specimens were thermally aged to modify the interfacial zone between the alumina fibers and the mg alloy matrix. the fatigue crack growth experiments were conducted with specimens having the fiber orientation in two directions. certain specimens had the fibers oriented parallel to the crack ... |
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| The Wetting, Reaction and Bonding of Silicon Nitride by Cu-Ti Alloys |
91 |
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| Authors:
D. H. Kim; S. H. Hwang; S. S. Chun; KOREA ADVANCED INST OF SCIENCE AND TECHNOLOGY SEOUL DEPT OF MATERIALS SCIENC E AND ENGINEERING*
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| The wettability and reactivity of pressureless sintered Si3N4 by powdered Cu-Ti alloy were investigated using sessile drop tests conducted in a vacuum. Bonding of Si3N4 to itself was also carried out and joint strength was evaluated by compressive shear testing. The correlation of wetting behavior with reaction and bond strength was interpreted. The wettability of Cu-Ti alloys on Si3N4 was improved greatly by addition of titanium up to 50 wt%. ... |
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| Microstructural Coarsening at High Temperatures in Rapidly Solidified Ti-5wt.%Al-2.9wt.%Y and Ti-5wt.%Al-7.5wt.%Th |
FEB 88 |
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| Authors:
S. H. Whang; W. W. Park; P. K. Kim; D. H. Kim
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| Rapidly solidified ribbons of Ti-5Al-2.9Y and Ti-5Al-7.5Th alloys (where the composition is an approximate weight percent) were prepared by the arc melt-spinning technique. These ribbons were chopped and consolidated by hot isostatic pressing at 850 C for 3 h. The microstructures of both as-quenched alloys are characterized by a uniform dispersion spherical dispersoids in the matrix. Isothermal annealing of these alloys at 900 C results in the coarsening of grains ... |
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| the contact potential difference (cpd) measurement method for prebond nondestructive surface inspection |
JUL 78 |
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| Authors:
D. H. Kim; E. F. Sutliff
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| for primary bonded structural applications the assurance of reliability and durability of bonded joints becomes more critical, and consequently, nondestructive inspection tools must be developed to ensure the adequacy of each step of the bonding process. the objective of this research was to develop instruments and procedures to be used prior to bonding to ensure proper surface treatment of aluminum bonding surfaces and to detect surface contaminations. through this work ... |
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| Application of the Dielectric Analysis to Polymeric Materials Control, |
06 JUL 1976 |
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| Authors:
D. H. Kim
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| Specific applications to the dielectric and the DC conductance technique to control polymeric materials are described. A dielectric method is proposed which can provide an objective test for gel time measurement in place of the conventional method which is rather subjective. Simultaneous operation of the dielectric and the DC conductance can determine when the cure cycle is complete and when pressure should be applied during the cure cycle to have ... |
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| feasibility of nondestructive inspection method for surface bondability |
APR 76 |
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| Authors:
D. H. Kim; E. F. Sutliff
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| adhesive bonding has been used on secondary structure for many years and is now being extended to carry primarystructural loads in many applications. therefore, the assurance of reliability and durability of bondjoints is more critical. nondestructive inspection (ndi) has been routinely used to assure that adhesive bonds are free of voids and delamination, however, techniques to nondestructively assure the integrity of a surface prior to bonding have been grossly lacking. ... |
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| FEASIBILITY OF NONDESTRUCTIVE INSPECTION METHOD FOR SURFACE BONDABILITY |
76 |
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| Authors:
D. H. Kim; E. F. Sutliff; E. Hisey; BOEING COMMERCIAL AIRPLANE CO SEATTLE WASH
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| Adhesive bonding has been used on secondary structures for many years and is now being extended to carry primary structural loads in many applications. Therefore, the assurance of reliability and durability of bond joints is more critical. Nondestructive Inspection (NDI) has been routinely used to assure that adhesive bonds are free of voids and delaminations, however, techniques to nondestructively assure the integrity of a surface prior to bonding have been ... |
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| The thermophysical properties of fiber reinforced plastics. |
APR 72 |
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| Authors:
D. H. Kim; BOEING CO SEATTLE WASH
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| The thermophysical properties, thermal conductivity and heat capacity of fiber reinforced plastics have been examined experimentally and analytically to define the effect of reinforcement fabrice type, amount of resin, and various resins and reinforcements. Thermal conductivity was measured using a guarded hot plate thermal conductivity instrument and heat capacity determined with a differential scanning calorimeter. The range of temperature was from room temperature to about 300 F. Resin system included ... |
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