Precipitation during cooling of 7XXX aluminum alloys

Effect of Zn Concentration on the Microstructure and Mechanical Properties of Al-Mg-Si-Zn Alloys Processed by Gravity Die Casting

“…A numerical model has also been established to prove that the s phase exists with the increasing Mg content in Al-6 wt pct Zn-2 wt pct Cu-(1 to 4) wt pct Mg alloys. [36] With the addition of silicon, the precipitates observed in Al-Zn-Mg-Si-based alloys are slightly different. The precipitates reported in the literature are given in Table V.…”

Role of Small Addition of Sc and Zr in Clustering and Precipitation Phenomena Induced in AA7075

“…Despite having some disagreements and obscurity about the arrangement and the types of the hardening phases in the alloys, the decomposition of supersaturated solid solution is in the consistency with two precipitation sequences, where η′(MgZn2)phase (hexagonal)/η(MgZn2)-phase (hexagonal) and T′(Al2Zn3Mg3)-phase (hexagonal)/T(Al2Zn3Mg3)-phase (cubic) occur [15,19,20]. The precipitation of the semi-coherent η′-and T′-phases usually cause the age-hardening of the materials in contrast to the incoherent η-and T-phases [19,20,[22][23][24][25][26][27]. Many authors use different designations for the early precipitation phases formed during the precipitation; (co-)clusters/Guinier-Preston (GP) zones of different types usually appear during ageing at temperatures lower than ~150 °C [19,20,25,[28][29][30][31][32][33].…”

Fatigue Life of 7475-T7351 Aluminum After Local Severe Plastic Deformation Caused by Machining

“…Precipitated Al-Fe-Si and Al-Mg-Cr dispersoids (possibly Al 12 Fe 3 Si; Al 12 Mg 2 Cr) were formed by solid state precipitation in the grain boundaries. Third, observed secondary phases can be described as fine metastable precipitates in the material matrix (sizes from 2 nm up to 0.6 µm) and these are responsible for strengthening of the alloy (via GP , ή or η ) [22,23].…”