| Pyrometallurgical, Physical, and Mechanical Behavior of Weldments |
30 JAN 96 |
15 pages |
| Authors:
David L. Olson; Robert H. Frost; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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 | This research program aimed to achieve a better understanding of pyrometallurgical reactions during welding and process-microstructure correlations. The validity of proposed mechanisms for the formation of weld metal acicular ferrite was tested by using selected surrogate additions with similar chemical behavior but different physical properties compared to titanium-boron additions known to promote acicular ferrite formation. The results suggest that inclusion density and size distribution are the most important factors in ... |
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| Pressureless Infiltration of Ceramics by Molten Metals |
DEC 95 |
105 pages |
| Authors:
P. R. Chidambaram; G. R. Edwards; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| Pressureless infiltration of molten metals into ceramics is perhaps the most cost- effective approach to liquid-metal processing of metal-matrix composites. Two approaches are currently being investigated for their respective pressureless infiltration potential. A 'carrier oxide' approach to infiltration relies on the use of a intermediary liquid oxide which carriers the liquid metal into the capillary channels of the porous ceramic. The effectiveness of this approach was discovered by understanding the ... |
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| Fundamental Aspects of Metal-to-Ceramic Brazing |
OCT 95 |
154 pages |
| Authors:
Glen R. Edwards; Stephen Liu; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| Research has continued to develop fundamental understanding of wetting and spreading of reactive metals on alumina and to model the metal to ceramic bonding process. A study was completed on the modeling of spreading kinetics of reactive brazing alloys on ceramic substrates. Based on nucleation and growth of islands of reaction product at the ceramic- metal interface, in particular, the Avrami type surface nucleation and growth kinetics, Dr. Alan Meyer ... |
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| Hydrogen Cracking Behavior in an Iron Aluminide Alloy Weldment |
1995 |
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| Authors:
A. A. Fasching; D. I. Ash; G. R. Edwards; S. A. David; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| Heat Treatment of Investment Cast PH 13-8 Mo Stainless Steel: Part I. Mechanical Properties and Microstructure |
1994 |
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| Authors:
P. W. Hochanadel; C. V. Robino; G. R. Edwards; M. J. Cieslak; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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 | The microstructure of investment cast PH 13-8 Mo stainless steel heat-treated to various conditions was studied using light and electron microscopy, electron probe microanalysis, and Mossbauer spectroscopy. The mechanical properties were investigated by using uniaxial tensile testing, hardness testing, and Charpy impact testing. The beta-NiAl strengthening precipitates were difficult to resolve by transmission electron microscopy in specimens aged at low temperatures (566 C and below). A high dislocation density was ... |
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| Grain Growth Kinetics of an Iron Aluminide Alloy. |
1994 |
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| Authors:
A. A. Fasching; G. R. Edwards; S. A. David; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| An iron aluminide alloy, FA-129, was processed using different thermomechanical treatments to obtain samples with various grain sizes and strain energies. Grain growth behavior was studied and data were fitted to a power law equation. Relationships between the initial sample conditions and subsequent growth rates are discussed. |
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| Wetting and Spreading of Manganese and Copper-Manganese Alloys on Alumina Surfaces. |
1994 |
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| Authors:
A. Meier; V. Gabriel; PR. Chidambaram; G. R. Edwards; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| In this study, the wetting and spreading of manganese and copper-manganese alloys on polycrystalline alumina was studied using a sessile drop technique. the contact angle, solid-liquid interfacial energy and the work of adhesion values were calculated based on the experimentally measured spread radius for five to forty weight percent manganese in the temperature range of 1100 to 1300 c. these values were similar, but slightly higher, than the values reported ... |
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| The Influence of Weld Metal Alloying Additions to Extend the Heat Input Range for the Submerged Arc Welding of High Strength Steels |
16 DEC 93 |
46 pages |
| Authors:
S. Liu; D. L. Olson; J. E. Ramirez; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| Weld metal microstructural development for high strength steels when welded with submerged arc welding process was investigated as a function of consumable composition and thermal experience. Of specific interest is the effect of systematic variations of microalloying additions on broadening of applicable heat input range. Controlled weld metal oxygen content, particularly in the range of 300 to 400 ppm, has been found to improve HY-130 steel weld metal toughness. Molybdenum ... |
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| Wettability and Reaction Kinetics in Metal Matrix Composites |
AUG 93 |
59 pages |
| Authors:
Glen R. Edwards; David L. Olson; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| Research accomplishment during the last academic year are in two related areas: (a) further applications of the thermodynamic model developed in the previous years, and (b) kinetic studies in alumina/reactive metal systems. The ongoing projects are adaptations of the research findings from the previous years, aimed at improving the wettability at an aluminum/alumina interface and understanding the nature of the oxide barrier formed at the ceramic/liquid aluminum interface. |
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| The Pyro-Metallurgical, Physical, and Mechanical Behavior of Weldments |
AUG 92 |
22 pages |
| Authors:
R. H. Frost; D. L. Olson; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| The physical and chemical behavior of welding consumables were investigated in studies of the titanium and zirconium as grain refining nucleants in aluminum alloys, and studies of the influence of titanium, zirconium and boron additions on oxide inclusion formation and on the nucleation of acicular ferrite in microalloyed steel weld metal. The influence of electrochemical reactions during arc welding on weld metal composition was investigated for direct current welding processes ... |
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| Infiltration Kinetics and Interfacial Bond Strength of Metal Matrix Composites |
JUL 92 |
86 pages |
| Authors:
Glen R. Edwards; David L. Olson; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| The research accomplishments for this three-year metal matrix composite research program centered upon three areas: infiltration kinetics, wettability studies and predictions of interfacial properties. A pre- conditioning reaction model was hypothesized to explain the incubation period observed to precede the liquid metal infiltration of SiC particulate, and a rate equation for pre-conditioning was experimentally established for the infiltration of SiC particulate by liquid aluminum. Experimental wettability studies were completed for ... |
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| Shielded Metal Arc Welding Consumables for Advanced High Strength Steels |
FEB 92 |
83 pages |
| Authors:
S. Liu; G. L. Fredrickson; M. Q. Johnson; G. R. Edwards; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| To achieve the goal of developing adequate shielded metal arc (SMA) welding consumables for advanced high strength steels, the complex relationship between flux coating and base metal must be understood. This report is concerned with the effect of flux ingredients on high strength steel welding. Submerged arc (SA) welding was first used to investigate the performance of 45 experimental flux compositions chosen from the CaCO3-SiO2-K2SiO3-CaF2-Fe system. Bead-onplate welds were produced ... |
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| Metallography of HSLA Steel Weldments |
92 |
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| Authors:
S. Liu; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| A review on the microstructures of HSLA steel weldments, and the various techniques used in their study, has been presented. |
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| Fundamental Issues Concerning the Microdesigning of Metal-Ceramic Interfaces. |
1992 |
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| Authors:
P. R. Chidambaram; G. R. Edwards; D. L. Olson; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, analytical, composite materials, cmc data, data, mmc data, reinforcement data, survey materials and material types:, ceramics, eutectic compositions, ni matrix, single crystal al-nb material characteristics and data fields:, bond energy, chemical bonds, chemical wetting, cte, modulus data, physical wetting, shear modulus, spreading, surface energies, wettability parameter values relevant to the data:, ... |
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| Wetting of Ceramic by Molten Metals: Rate Controlling Phenomena. |
1992 |
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| Authors:
P. R. Chidambaram; G. R. Edwards; D. L. Olson; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, mmc, models materials and material types:, oxide lattice material characteristics and data fields:, wettability parameter values relevant to the data:, -1100 c - -1000 c, 1000 c - 1100 c, 900 c - 1000 c miscellaneous and special technical terms:, n00014-88-k-0500 contracts, onr, point defect chemistry, sdio, transport models, welding research ... |
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| High Temperature Deformation and Fracture Behavior of Laminate Composites: The Importance of Interdiffusion During Creep. |
1992 |
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| Authors:
S. H. Wang; D. K. Matlock; D. L. Olson; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| Composites, as well as materials with solidified structures, exhibit composition and microstructures which vary with position and mechanical properties and are often described based on the rule of mixtures (1-3). choi et al (2,4) showed that the high temperature creep behavior of monel alloy 400 (a ni-cu alloy) weld metal and ni-cu laminate composites were described by a (1-3) analysis when the microstructures and composition gradients could be assumed constant ... |
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| Phase Stability of Fe-Al-Cr-Ni Weld Metal |
91 |
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| Authors:
B. F. Carpenter; D. L. Olson; D. K. Matlock; M. J. Cieslak; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| The weld metal of three austenitic iron-based alloys have been examined analytically using electron microscopy techniques; these alloys, having the designations Fe-2Al-8Cr-20Ni, Fe-4Al-10Cr-20Ni and Fe-5Al-14Cr-25Ni, are similar in composition to stainless steels with high aluminum additions; electron microanalysis of the solidification structure revealed that aluminum and chromium had segregated to the interdendritic volume; nickel and iron were found to be depleted within the interdendritic volume; austenite phase stability was evaluated ... |
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| Fundamental Concepts of Wettability and Interfacial Bond Strength in Aluminum Matrix, SiC-Reinforced Composites |
JUL 90 |
52 pages |
| Authors:
Glen R. Edwards; David L. Olson; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| Research accomplishments include: Surface Energy Measurement - Differential optical reflectance was used to measure the optical transitions in aluminum and its alloys. The semi-empirical correlation developed earlier was used to calculate the surface energy from the measured transition energies. PRedicted surface energies, using the model, were in close agreement with experimentally determined surface energies found in the literature. Wettability Predictions - Wettability studies are based on surface tension measurements from ... |
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| Recent Developments in HSLA Steel Welding |
90 |
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| Authors:
G. R. Edwards; S. Liu; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| A selective review of the progress made in the arc welding of HSLA steels is presented from a metallurgical point of view. Discussion is focused upon microstructural control of weld metal through control of the relevant solid-state phase transformations. Factors affecting the transformation kinetics for grain boundary ferrite and for acicular ferrite are emphasized. The paper concludes with the suggestion that electrochemical contributions to the weld pool composition and theoretical ... |
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| Fundamental Concepts of Wettability and Interfacial Bond Strength in Aluminum Matrix, SiC-Reinforced Composites. |
1990 |
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| Authors:
Glen R. Edwards; David L. Olson; COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WELDING AND JOINING RESEARCH
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| Research accomplishments include: surface energy measurement -differential optical reflectance was used to measure the optical transitions in aluminum and its alloys. the semi-empirical correlation developed earlier was used to calculated the surface energy from the measured transition energies. predicted surface energies, using the model, were in close agreement with experimentally determined surface energies found in the literature. wettability predictions-wettability studies are based on surface tension measurements from the capillary rise ... |
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Reports by Corporate Author
