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Type Hunt, Warren H. Jr.; Maruyama, Benji
  Publication The World Still Wont Beat a Path to Your Door: Transitioning DRA to the Marketplace Volume Journal Article
Pages 1999
  Abstract JOM  
  Corporate Author  
Publisher 51  
Editor 11
  Summary Language 62-64 Series Editor  
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  Expedition Notes  
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no NU @ karnesky @ 549
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Li, Yong; Langdon, Terence G. Creep behavior of an Al-6061 metal matrix composite reinforced with alumina particulates Journal Article 1997 Acta Materialia Acta Mater. 45 11 4797-4806 Creep tests were conducted on an Al-6061 matrix alloy reinforced with 20 vol.% of irregularly shaped Al2O3 particulates. The composite was fabricated using an ingot metallurgy technique and the creep properties were determined at temperatures from 623 to 773 K. The results show high values for both the apparent stress exponent (up to > 10) and the apparent activation energy for creep (~ 200–275 kJ/mol) but it is demonstrated, by incorporating a threshold stress into the analysis, that the true stress exponent is close to 3 and the true activation energy is close to the value for diffusion of Mg in the Al matrix. The results suggest that creep is controlled by the viscous glide of dislocations in the Al-6061 matrix alloy. Very fast creep rates are observed at the highest stress levels owing to the breakaway of dislocations from their solute atom atmospheres. Direct comparison shows that the creep resistance of this composite is less than in an Al-6061 alloy reinforced with 20 vol.% of Al2O3 microspheres. This difference is attributed to the creation of additional precipitates in the microsphere-reinforced composite because of an interfacial reaction between the matrix alloy and the reinforcement. no NU @ karnesky @ 562
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Li, Yong; Langdon, Terrence G. A simple procedure for estimating threshold stresses in the creep of metal matrix composites Journal Article 1997 Scripta Materialia Scripta Mater. 36 12 1457-1460 no NU @ karnesky @ 563
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My, Yan; Langdon, Terence G. Creep behavior of an Al-6061 metal matrix composite produced by liquid metallurgy processing Journal Article 1997 Materials Science and Engineering A Mater. Sci. Eng. A 230 1-2 183-187 Activation energy; Alumina microspheres; Aluminum composite; Creep; Stress exponent; Threshold stress Constant stress creep tests were conducted on an Al-6061 metal matrix composite reinforced with alumina microspheres and produced using liquid metallurgy processing. By introducing a threshold stress into the creep analysis, it is concluded that creep occurs by viscous glide in the matrix with a stress exponent of ≈ 3 and an activation energy of ≈125 kJ mol−1. The threshold stress is probably associated with the presence of fine spinel crystals which have been identified in the matrix of the composite. no NU @ karnesky @ 715
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Fu, Jingbo; Nie, Zuoren; Jin, Tounan; Zou, Jingxia; Zuo, Tieyong Effect of Er on Aging Behavior of 1420 Alloy Journal Article 2005 Journal of Rare Earths 23 Suppl 430-433 aging behavior; 1420 alloy; Er; delta '; Al3Er Effect of trace rare earth Er addition on the aging behavior of 1420 alloys was studied using hardness testing. Precipitation behavior during aging was investigated by electron microscopy transmission. It is found that small amounts of Er can modify the aging behavior of 1420 alloy , for example , improve the hardness and shift peak aging time . All those results may be attributed to the increase of diffusion coefficient of Li atom in the Al matrix added with Er . As a conse2 quence , rate of nucleation and growth ofδ′(Al3Li) was promoted ; the Al3Er particles act as preferential sites for the nu2 cleation and growth ofδ′, which in turn results in the presentation of more composite particles . Beijing Univ Technol, Sch Mat Sci & Engn, Beijing 100022, Peoples R China, Email: zrnie@bjut.edu.cn Metallurgical Industry Press English 1002-0721 ISI:000236093300110 no NU @ karnesky @ 791
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Deconihout, B.; Vurpillot, F.; Bouet, M.; Renaud, L. Improved ion detection efficiency of microchannel plate detectors Journal Article 2002 Review of Scientific Instruments Rev. Sci. Instrum. 73 4 1734-1740 The knowledge of the detection efficiency of the microchannel plate is of upmost importance in many applications using this type of particle detector. However, few attempts have been made to measure the absolute value of the detection efficiency of microchannel plates. In this article, a new way of accurately measuring the absolute value of the detection efficiency is described. When particles hit the detector in the interchannel web of the microchannel plate, secondary electrons are generated. These secondary electrons can be returned to neighboring channels by means of an electric field applied at the front face of the detector. The resulting increase in the detection efficiency has been quantified using the absolute measurement of the detection efficiency. It is found that the value of the returning field has to be carefully set in order to prevent detection artifacts that may lead to a wrong estimation of the detection efficiency. In the best conditions, the detection efficiency increase reaches 40%. no NU @ karnesky @ 806
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Zhang, Y.; Blazquez, J.S.; Conde, A.; Warren, P.J.; Cerezo, A. Partitioning of Co during crystallisation of FeCoNbB(Cu) amorphous alloys Journal Article 2003 Materials Science and Engineering A Mater. Sci. Eng. A 353 1-2 158-163 Amorphous; Soft magnetic; Atom probe; Nanocrystallisation; Microstructure Partitioning behaviour of alloying elements during the primary crystallisation of both Fe18Co60Nb6B16 and Fe39Co39Nb6B15Cu1 alloys has been studied using three-dimensional atom probe (3DAP). Cu rich clusters were found in the Cu-containing alloy, and they provided nucleation sites for the primary α-Fe(Co) particles. In the Cu clusters, concentration of both Fe and Co was greatly decreased. In both Cu-containing and Cu-free alloys Nb and B were depleted in the α-Fe(Co) particles and enriched in the remaining amorphous phase. However, Co concentration in the α-Fe(Co) was the same as the remaining amorphous phase. Based on the 3DAP analysis, the phase volume fraction has been estimated. no NU @ karnesky @ 818
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Boettinger, W. J.; Warren, J. A.; Beckermann, C.; Karma, A. Phase-Field Simulation of Solidification Journal Article 2002 Annual Review of Materials Research 32 163-194 refbase @ user 972
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Carreno, F.; Eddahbi, M.; Ruano, O. A. Creep Behaviour of Three Dispersion-Strengthened Al-Fe-V-Si Materials Journal Article 1997 Journal of Materials Science Letters 16 21 1728-1730 refbase @ user 1010
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Deconihout, B.; Renaud, L.; Da Costa, G.; Bouet, M.; Bostel, A.; Blavette, D. Implementation of an Optical {TAP}: Preliminary Results Journal Article 1998 Ultramicroscopy 73 1-4 253-260 The FIM Group of the University of Rouen is developing a new type of detector that can be used in atom probe and 3D atom probe applications. This detector consists of an array of conductive and transparent strips covered with a phosphorescent material. After having produced light, electrons generated by ionic impacts onto microchannel plates produce signals on strips that are used for timing. At the same time, light produced by ions on the phosphor screen is recorded by means of a CCD image sensor. Then, the comparison between positions and the distribution of time of flight on the strip array makes it possible to correlate positions and times for each event. In this contribution, preliminary results obtained with a 5 x 5 cm2 detector having eight strips will be shown. Potential capabilities and performance will be discussed. TY - JOUR refbase @ user 1056
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