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:
The quantitative correlation between strength, ductility and precipitate microstructures inthe vicinity of grain boundaries with precipitate free zones (PFZ) was evaluated for Al-Zn-Mg(-Ag,Cu) alloys using transmission electron microscopy (TEM), three-dimensional atom probe (3DAP)and tensile test. In the Al-Zn-Mg ternary and Cu-added alloys aged at 433K, larger widths of PFZwere observed by TEM and resulted in lower elongations to fracture, independent of the size of grainboundary precipitates. On the other hand, the elongation of the Ag-added alloy was higher, ifcompared at the same levels of proof stress, due to the much smaller width of PFZ. This stronglysuggests that PFZ is harmful to fracture of the investigated alloys. From a 3DAP analysis,furthermore, it was revealed that Ag and Cu atoms are incorporated in the nanoclusters from theinitial stage of aging. In this work, the elongation was well correlated to the width of PFZ, size ofgrain boundary precipitates and the level of proof stress, enabling to predict ductility of the alloysfrom known microstructural factors
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.519-521.431.pdf
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