ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Solid solution treatment at 450°C and 550°C and subsequent two step age hardening at100°C and 150 °C up to 144 hrs. have been carried out for two conventional and four experimental7xxx type of alloys with different Mg, Zn, Fe and Si content. The influence of silicon on phase andkinetics of age hardening zones and particles has been followed. Increase in silicon required highersolid solution temperature in order to achieve reasonable age hardening response. High siliconalloys, solid solution treated at high temperature, have tendency to recrystallize during aging. TheGP-zone formation is affected by the ratio between Mg, Zn and Si. In alloys with Mg/Zn ratio inthe range 1:2 GP(I)-type zones are formed, at higher solid solution temperature also GP(II); lowMg-content favor GP(II)- zones. In high silicon alloys GP-zones of b’’’-type (from the Al-Mg-Si)system contribute to age hardening. The precipitation kinetics of the main hardening phase h’, isinfluenced by the preceding GP-zone stage
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.519-521.579.pdf
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