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Amorphous rare earth magnet powders

Description: Gas atomization (GA) processing does not generally have a high enough cooling rate to produce the initial amorphous microstructure needed to obtain optimal magnetic properties in RE{sub 2}Fe{sub 14}B alloys. Phase separation and an underquenched microstructure result from detrimental {alpha}-Fe precipitation, and the resulting magnetic domain structure is very coarse. Additionally, there is a dramatic dependence of the magnetic properties on the cooling rate (and therefore the particle size) an… more
Date: August 1996
Creator: Sellers, C. H.; Branagan, D. J.; Hyde, T. A.; Lewis, L. H. & Panchanathan, V.
Partner: UNT Libraries Government Documents Department
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Rapidly-Solidified Permanent Magnet Materials: Factors Affecting Quenchability and Magnetic Properties in Nd{Sub 2}Fe{Sub 14}B

Description: Insight into the solidification behavior of Nd{sub 2}Fe{sub 14}B-based materials processed by rapid solidification techniques has been obtained by a systematic experimental study of the Curie temperatures of selected phases found in these materials. Nd{sub 2}Fe{sub 14}B-based materials fabricated by two disparate rapid solidification techniques, inert gas atomization (IGA) and melt-spinning, has been studied. The compositions of the starting materials have been altered with additions of the ref… more
Date: November 2, 1999
Creator: Lewis, L. H.; Kramer, M. J.; Mccallum, R. W. & Branagan, D. J.
Partner: UNT Libraries Government Documents Department
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A metallurgical approach toward alloying in rare earth permanent magnet systems

Description: TiC is added as an alloying agent to Nd{sub 2}Fe{sub l4}B (2-14-1) system to both alter the solidification behavior of the melt and to act as pinning sites to control grain growth. The addition of TIC to 2-14-1 results in a factor of three reduction of the quench rate required to produce amorphous material. In addition, the crystallization temperature of the glass is enhanced leading to enhanced nucleation and finer grain size during crystallization. TIC additions to the stochiometric melt affe… more
Date: December 31, 1995
Creator: McCallum, R. W.; Willard, M. A.; Dennis, K. W.; Branagan, D. J. & Kramer, M. J.
Partner: UNT Libraries Government Documents Department
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Corrosion Resistances of Iron-Based Amorphous Metals with Yttrium and Tungsten Additions in Hot Calcium Chloride Brine & Natural Seawater: Fe48Mo14Cr15Y2C15B6 and W-Containing Variants

Description: Yttrium-containing SAM1651 (Fe{sub 48.0}Cr{sub 15.0}Mo{sub 14.0}B{sub 6.0}C{sub 15.0}Y{sub 2.0}), has a critical cooling rate (CCR) of approximately 80 Kelvin per second, while SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) with no yttrium has a higher critical cooling rate of approximately 600 Kelvin per second. SAM1651's low CCR enables it to be rendered as a completely amorphous material in practical materials processes. Chromium (Cr), molyb… more
Date: October 20, 2006
Creator: Farmer, J C; Haslam, J; Day, S; Lian, T; Saw, C; Hailey, P et al.
Partner: UNT Libraries Government Documents Department
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Corrosion Resistance of Amorphous Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 coating - a new criticality-controlled material

Description: An iron-based amorphous metal with good corrosion resistance and a high absorption cross-section for thermal neutrons has been developed and is reported here. This amorphous alloy has the approximate formula Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} and is known as SAM2X5. Chromium (Cr), molybdenum (Mo) and tungsten (W) were added to provide corrosion resistance, while boron (B) was added to promote glass formation and the absorption of thermal neu… more
Date: March 28, 2007
Creator: Farmer, J C; Choi, J S; Saw, C K; Rebak, R; Day, S D; Lian, T et al.
Partner: UNT Libraries Government Documents Department
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Quantification of corrosion resistance of a new-class of criticality control materials: thermal-spray coatings of high-boron iron-based amorphous metals - Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4

Description: An iron-based amorphous metal, Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} (SAM2X5), with very good corrosion resistance was developed. This material was produced as a melt-spun ribbon, as well as gas atomized powder and a thermal-spray coating. Chromium (Cr), molybdenum (Mo) and tungsten (W) provided corrosion resistance, and boron (B) enabled glass formation. The high boron content of this particular amorphous metal made it an effective neutron abs… more
Date: March 28, 2007
Creator: Farmer, J. C.; Choi, J. S.; Shaw, C. K.; Rebak, R.; Day, S. D.; Lian, T. et al.
Partner: UNT Libraries Government Documents Department
open access

Long-Term Corrosion Tests of Prototypical SAM2X5 (Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) Coatings

Description: An iron-based amorphous metal with good corrosion resistance and a high absorption cross-section for thermal neutrons has been developed and is reported here. This amorphous alloy has the approximate formula Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} and is known as SAM2X5. Chromium (Cr), molybdenum (Mo) and tungsten (W) were added to provide corrosion resistance, while boron (B) was added to promote glass formation and the absorption of thermal neu… more
Date: May 10, 2007
Creator: Farmer, J C; Choi, J S; Saw, C K; Rebak, R H; Day, S D; Lian, T et al.
Partner: UNT Libraries Government Documents Department
open access

Corrosion Characterization of Iron-Based High-Performance Amorphous-Metal Thermal-Spray Coatings

Description: New corrosion-resistant, iron-based amorphous metals have been identified from published data or developed through combinatorial synthesis, and tested to determine their relative corrosion resistance. Many of these materials can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS N06022) in some very aggressive environments, including concentrated calcium-chloride brines at elevated temperatur… more
Date: March 21, 2005
Creator: Farmer, J. C.; Haslam, J. J.; Day, S. D.; Branagan, D. J.; Blue, C. A.; Rivard, J. K. et al.
Partner: UNT Libraries Government Documents Department
open access

Corrosion Resistances of Iron-Based Amorphous Metals with Yttrium and Tungsten Additions in Hot Calcium Chloride Brine & Natural Seawater: Fe48Mo14CR15Y2C15B6 and Variants

Description: The passive film stability of several Fe-based amorphous metal formulations have been found to be comparable to that of stainless steels and Ni-based Alloy C-22 (UNS No. N06022), based on electrochemical measurements of the passive film breakdown potential and general corrosion rates. Electrochemical studies of the passive film stability of SAM1651 are reported here. Chromium (Cr), molybdenum (Mo) and tungsten (W) provide corrosion resistance; boron (B) enables glass formation; and rare earths … more
Date: October 12, 2006
Creator: Farmer, J; Haslam, J; Day, S; Lian, T; Saw, C; Hailey, P et al.
Partner: UNT Libraries Government Documents Department
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Electrochemical Studies of Passive Film Stability on Fe48Mo14Cr15Y2C15B Amorphous Metal in Seawater at 90oC and 5M CaCl2 at 105oC

Description: Several Fe-based amorphous metal formulations have been identified that appear to have corrosion resistance comparable to, or better than that of Ni-based Alloy C-22 (UNS N06022), based on measurements of breakdown potential and corrosion rate in seawater. Both chromium (Cr) and molybdenum (Mo) provide corrosion resistance, boron (B) enables glass formation, and rare earths such as yttrium (Y) lower critical cooling rate (CCR). Amorphous Fe{sub 48.0}Cr{sub 15.0}Mo{sub 14.0}B{sub 6.0}C{sub 15.0}… more
Date: April 25, 2007
Creator: Farmer, J. C.; Day, S. D.; Lian, T.; Saw, C. K.; Hailey, P. D.; Blue, C. A. et al.
Partner: UNT Libraries Government Documents Department
open access

High-Performance Corrosion-Resistant Iron-Based Amorphous Metals - The Effects of Composition, Structure and Environment: Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4

Description: Several Fe-based amorphous metal formulations have been identified that appear to have corrosion resistance comparable to (or better than) that of Ni-based Alloy C-22 (UNS No. N06022), based on measurements of breakdown potential and corrosion rate in seawater. Both chromium (Cr) and molybdenum (Mo) provide corrosion resistance, boron (B) enables glass formation, and rare earths such as yttrium (Y) lower critical cooling rate (CCR). SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.… more
Date: October 20, 2006
Creator: Farmer, J; Haslam, J; Day, S; Lian, T; Saw, C; Hailey, P et al.
Partner: UNT Libraries Government Documents Department
open access

High-Performance Corrosion-Resistant Iron-Based Amorphous Metals: The Effects of Composition, Structure and Environment on Corrosion Resistance

Description: New corrosion-resistant, iron-based amorphous metals have been identified from published data or developed through combinatorial synthesis, and tested to determine their relative thermal phase stability, microstructure, mechanical properties, damage tolerance, and corrosion resistance. Some alloy additions are known to promote glass formation and to lower the critical cooling rate [F. Guo, S. J. Poon, Applied Physics Letters, 83 (13) 2575-2577, 2003]. Other elements are known to enhance the cor… more
Date: April 11, 2006
Creator: Farmer, J; Choi, J S; Haslam, J; Lian, T; Day, S; Yang, N et al.
Partner: UNT Libraries Government Documents Department
open access

Electrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 90oCElectrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 9

Description: An iron-based amorphous metal, Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} (SAM2X5), with very good corrosion resistance was developed. This material was prepared as a melt-spun ribbon, as well as gas atomized powder and a thermal-spray coating. During electrochemical testing in several environments, including seawater at 90 C, the passive film stability was found to be comparable to that of high-performance nickel-based alloys, and superior to that … more
Date: April 25, 2007
Creator: Farmer, J C; Haslam, J; Day, S D; Lian, T; Saw, C K; Hailey, P D et al.
Partner: UNT Libraries Government Documents Department
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