Effect of activated alloys on hydrogen discharge kinetics of MgH2 nanocrystals

This is the post-print version of the final paper published in Journal of Alloys and Compounds. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2007 Elsevier B.V.Activated alloys synthesized by arc-melting were examined as catalysts for improving the hydrogen sorption characteristics of nanostructured magnesium hydride, proposed as a reversible hydrogen storage material. The MgH2-catalyst absorbing materials were prepared by ball milling of pure MgH2 with hydrided Zr47Ni53, Zr9Ni11, and other investigated alloys. The nanostructured MgH2-intermetallic systems were tested at 250 °C and catalyst addition of eutectoid Zr47Ni53 resulted in the fastest desorption time and highest initial desorption rate. Also, the catalyzed Mg-hydride with activated Zr9Ni11 and Zr7Ni10 phases showed fast desorption kinetics. Moreover, the results demonstrated that the composition of dispersed ZrxNiy catalysts has a strong influence on the amount of accumulated hydrogen and desorption rate of Mg-nanocomposite.National Research Council Canad

Phase Structure-Mechanical Property Relationships in HVOF-Sprayed WC-12Co Coatings

Peer reviewed: YesNRC publication: Ye

Tensor-Krylov Methods for Large Sparse Systems of Nonlinear Equations

In this paper, we describe tensor methods for large sparse systems of nonlinear equations based on Krylov subspace techniques for approximately solving the linear systems that are required in each tensor iteration. We refer to a method in this class as a tensor-Krylov algorithm. Tensor methods are general purpose methods that base each iteration upon a quadratic model of the nonlinear function, rather than the standard linear model, where the second order term is selected so that the model is hardly more expensive to form, store, or solve than standard models. They have been shown to have substantial advantages in reliability and efficiency over standard Newton methods. We describe comparative testing for a tensor-Krylov implementation versus an analogous implementation based on a Newton-Krylov method. The test results show that tensorKrylov methods are more efficient and robust than Newton-Krylov methods. 1 Introduction The aim of this paper is to show how the use of iterative method..

Bending behavior of HVOF produced WC-17Co coating: Investigated by acoustic emission

A four-point bend test using acoustic emission (AE) was used to compare coating properties under mechanical solicitation, mainly the toughness and spalling behavior. Coatings are made from the same material; Sulzer-Metco (Westbury, NY) 2005NS (WC-17Co) sprayed with an HVOF gun with different spray parameters. Coatings deposited on thin rectangular substrates were first bent in tension then in compression. AE features like the event number, energy per event, and cumulative energy were used to assess the damages in the coatings. The results are analyzed in relation to the coating microstructure.Peer reviewed: YesNRC publication: Ye

Abrasion and Erosion Behavior of WC and CrC Cermet Coatings

Peer reviewed: YesNRC publication: Ye

HVOF Coatings Properties of the Newly Thermal Spray Composition WC-WB-Co

Peer reviewed: YesNRC publication: Ye