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The structure, age hardening response, precipitate type and hardness of A319 cast aluminum alloy without and with zirconium addition were investigated. The as-solutionized and artificially-aged hardness values were higher for the Zr-containing alloy. This is believed to be a consequence of the precipitation of Al3Zr particles produced during sufficiently long solutionizing treatments. © 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved  

The balance equations for micromorphic materials with mass flux and mass production are determined based on the phenomenon of self-diffusion. In this study, the self-diffusive flux is the flux of mass of a single micromorphic species within itself which is captured by defining the relative macro-element spatial velocity vector and the relative micro-gyration tensor. By use of a binary micromorphic mixture theory, the self-diffusion of a single micromorphic species within itself results in an extra diffusive momentum field, an extra diffusive moment of momentum and their respective non-compliant terms. The concepts of the macro- and micro-mass flux are studied in the framework of the... 

The key feature of diffusion brazing, also referred to as transient liquid phase bonding, is isothermal solidification which precludes the formation of intermetallic in the joint centreline. Analysing the available data published in the literature showed that the composition of the nickel-based superalloys plays a strong role in determining the required time for obtaining intermetallic-free joint during diffusion brazing. This effect is not predictable by the standard conventional models. It is proposed that increasing the boride-forming elements in the base superalloy which promotes in situ boride precipitation at the diffusion-affected zone can accelerate the diffusion flux of the boron...