Microstructural evolution during extrusion and ECAP of a spray-deposited Al–Zn–Mg–Cu–Sc–Zr alloy

Influence of Processing Severity During Equal-Channel Angular Pressing on the Microstructure of an Al-Zn-Mg-Cu Alloy

“…[22] A careful inspection of the literature shows that the strategy followed in the majority of SPD-processed Al alloys to stabilize the microstructure at high temperature is to add small amounts of elements such as Sc and Zr. [23][24][25] A fine dispersion of Al 3 Sc and/or Al 3 Zr formed during casting acts as an inhibitor of grain growth at high temperatures. Consequently, high strain rate superplasticity (HSRS) has been observed at high temperatures.…”

“…By contrast, there have been only a limited number of reports on the pressing of more complex alloys, such as Al-Zn-Mg-(Cu) alloys, where aging treatments and precipitation kinetics become important features of the processing method. [23][24][25][26][27][28][29][30][31][32] In practice, these alloys are often difficult to process by ECAP at room temperature because of their very limited formability.…”

Tensile behaviours of equal channel angular pressed Al–11·5Zn–2Mg–1·5Cu–0·2Sc–0·15Zr alloy fabricated by spray forming at ambient and elevated temperatures

“…5. The microstructure of the eight passes equal channel angular pressed alloy was refined significantly to 800 nm, 13 resulting in a dramatic increase in ductility at elevated temperature.…”

“…The microstructures of the extruded and ECAP samples were investigated in our previous work. 13 It was shown that the grain size was refined to 800 nm after eight passes ECAP from 3?5 mm of the sprayed and then extruded alloy, with a few finer MgZn 2 and Al 3 (Sc,Zr) dispersing uniformly in the matrix, 13 which is sufficiently small for grain boundary sliding, and the grain size is relatively stable at lower deformation temperature of 300uC due to the presence of precipitates of Al 3 (Zr,Sc) at grain boundaries. On the other hand, the existence of a high volume fraction of dispersoids at triple points or grain boundaries leads to a decrease in ductility as well.…”

Isothermal deformation of spray formed Al–Zn–Mg–Cu alloy

“…were used to compact the material. There have been some previous studies on the extrusion research of the spray formed aluminium alloy (Jeyakumar et al, 2010;Ning et al, 2010;Cochrane, 2002, 2003;Sharma, 2008;Wang et al, 2009). Sharma et al reported that the mechanical properties of the extruded aluminium alloy of 12Zn-3.3 Mg-1.3Cu-0.3Mn-0.20Zr are tensile stress of 763.8 MPa, yield stress of 755.6 MPa and elongation 8.5% (Sharma et al, 2006), and the results show that the spray formed zinc-rich aluminium alloy is a suitable structural material with high strength.…”