Quantitative Evaluation of Microstructure in Weld Heat Affected Zone of Commerciall Al-Mg-Si Alloy by Means of Electrical Resistivity Measurement
1982 Volume 51 Issue 2 Pages 168-174
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1982 Volume 51 Issue 2 Pages 168-174
An investigation has been made into the microstructure of weld heat affected zone (HAZ) in commerciai Al-Mg-Si system 6063-T5 alloy.
The precipitation amounts of G.P.Zones, β' precipitates, β phase and relatively insoluble compounds respectively in the HAZ can be evaluated quantitatively by means of electrical resistivity measurement of an isochronal annealing technique.
The partial or all dissolution of G.P. Zones and β' precipitates occurs in a narrow band of the HAZ where the temperature has reached above 240°C during welding.
The softening zone remains in these parts of HAZ in spite of natural aging after welding.
The softening zone can be considerably improved by means of artifical aging treatment at 180°C for 8 hrs after welding.
