The role of heterogeneity on the flow and fracture of two-phase materials

International audienceno abstrac

Perspectives for Cu/SS macrocomposite and Cu/X nanofilamentary conductors used in non-destructive high-field pulsed magnets under cryogenic conditions

The latest activities concerning the research, development and applications of macrocomposite and nanocomposite reinforced conductors, able to resist both the heating and electrodynamic forces generated by the high transitory current in pulsed high-field magnets are discussed. (C) 2004 Elsevier B.V. All rights reserved

Role of damage on the flow and fracture of particulate reinforced alloys and metal matrix composites

International audienceno abstrac

An improved fluorimetric determination of alpha-mannosidase activity in bovine plasma.

This paper describes a manual fluorimetric method for the assay of acidic alpha-mannosidase activity in bovine plasma. The optimum conditions for the assay of this enzyme were studied. The assay method devised includes the addition of zinc to the substrate, which stimulates activity by approximately twofold, and reduces the optimum substrate concentration. This latter feature affords considerable cost saving in each test. We have also shown that the alpha-mannosidase activity in lithium heparin plasma, EDTA plasma and blood serum is the same whether the plasma/serum is separated from the cells/clot at 6, 20 or 25 hours after sample collection. This has eliminated the previous necessity of having to deliver whole blood samples to the laboratory within 6 hours of collection. Furthermore samples for the supplementary neutrophil assay can now be taken at the same time as those for the plasma test, and both samples forwarded together. The plasma alpha-mannosidase assay is a rapid and reliable screening test for the mannosidosis genotype and for detecting carrier animals. Carrying out this plasma assay in conjunction with the more definitive neutrophil assay provides a reliable method of distinguishing homozygotes and heterozygotes from normal animals

Damage mechanisms of model metal matrix composites with heterogeneous spatial distribution of the reinforcement

International audienceno abstrac

The Effect of Cellular Architecture on the Ductility and Strength of Metal Foams

A multiscale finite element model has been developed to study the fracture behaviour of two-dimensional random Voronoi structures. The influence of materials parameters and cellular architecture on the damage initiation and accumulation has been analyzed. The effect of the solid material's strain hardening, relative density and architectural randomness on the ductility and fracture strength of the cellular solid are investigated. The results suggest materials-design directions in which the heat treatment, the solid material properties, its microstructure and the cellular architecture can be tuned for an optimized performance of cellular materials

Effect of chemical composition on work hardening of Fe-Mn-C TWIP steels

The work hardening behaviour of Fe-Mn-C twinning induced plasticity (TWIP) steels with a wide compositional range has been investigated. Based on the consideration that twinning provides a dynamic composite effect resulting in high work hardening rate in TWIP steels, the present work proposes a model to describe such behaviour as a function of chemical composition. The model predictions are in good agreement with experimental observations. © 2011.link_to_subscribed_fulltex