Precipitation hardening in Cu 1.81 wt % Be 0.28 wt % Co
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The influence of prior cold work (50% reduction) on the ageing sequence of a Cu 1.81 wt % Be 0.28 wt % Co alloy has been investigated with transmission electron microscopy and hardness measurements. At low ageing temperatures (175‡ C), the effect of deformation is to reduce the vacancy concentration available for the formation of G.P. zones, with the subsequent retardation of the continuous precipitation sequence. In contrast, at higher ageing temperatures (315‡ C), recovery and recrystallization increased the available vacancy concentration and the continuous precipitation was accelerated in comparison to the undeformed alloy, while no discontinuous precipitation was noted. At ageing temperatures of 425‡ C, in addition to the continuous precipitation sequence, recrystallized grains of theγ equilibrium precipitate andα matrix were formed.
KeywordsPolymer Precipitation Microscopy Electron Microscopy Transmission Electron Microscopy
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