In order to clarify the behavior of precipitation and dissolution in Al-Mg-(La, Mm) alloys with a high Mg content(x≥7 wt.%) in detail, the characteristic parameter of DVRC (Differentiated values of the ratio of electrical resistivity change) depending on temperature has been investigated at a slow heating rate (0.05 K/min). Since the value of DVRC is very sensitive to its microstructural change, it enables us to understand the precipitation and dissolution behavior of phases clearly and quantitatively. During the heating, the transformation process of precursor phase, such as G. P. zone, shown as a positive peak at low temperature region, was retarded and the precipitation of β phase was suppressed by La or Mm addition. And the homogeneous precipitation of β phase was also induced by the additive elements of La or Mm. |
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