Abstract
The relation between discontinuous precipitation and continuous precipitation and the cell growth kinetics of the discontinuous precipitation in Cu-Mg alloys containing 2.0, 2.6 and 3.2 wt % Mg have been investigated, mainly by metallographic observation. The volume fraction of cells, the cell width and the interlamellar spacing have been determined by quantitative metallographic measurements. The cell growth rate decreases progressively with ageing time after the initial linear growth of the cells. This may be attributed to the influence of continuous precipitation on the cell growth. The volume fraction of the discontinuous precipitation cells,f, can be represented by the Johnson-Mehl equation: f=1−exp (−bt n). The value of the parameter n is about 2 and is independent of both the ageing temperature and alloy composition in the ageing range where the cell growth rates are constants. Mass transport of magnesium during the linear growth of cells occurs by grain boundary diffusion in a Cu-Mg solid solution.
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Tsubakino, H., Nozato, R. Discontinuous precipitation in Cu-Mg alloys. J Mater Sci 19, 3013–3020 (1984). https://doi.org/10.1007/BF01026980
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DOI: https://doi.org/10.1007/BF01026980