Comparison of precipitation kinetics and mechanical properties in Zr and Sc-bearing aluminum-based alloys

Investigation of Effect of Preliminary Annealing on Superplasticity of Ultrafine-Grained Conductor Aluminum Alloys Al-0.5%Mg-Sc

“…The Al 3 Sc particles were coherent to the Al crystal lattice: the elastic strain fields were observed near the particles while the interphase boundaries between the Al 3 Sc particles and the Al crystal lattice were diffused ( Figure 5 e,f, see also [ 38 ]). No large elongated Al 3 Sc particles, the presence of which evidences the intermittent mechanism of the particle nucleation (see [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ]) were found.…”

“…It was shown in [ 30 ] that intensive pore formation in the Al 3 Sc incoherent particles may be one of the factors limiting the ultimate superplastic characteristics of the UFG Al-0.5%Mg-Sc alloys. It should be stressed here that the formation of the Al 3 Sc particles in the investigated UFG alloys at reduced temperatures goes via a discontinuous precipitation mechanism (see [ 4 , 30 , 38 ]) similar to the low-temperature discontinuous solid solution decomposition in Al-Zr alloys [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ].…”

A High-Strain-Rate Superplasticity of the Al-Mg-Si-Zr-Sc Alloy with Ni Addition

“…It has been suggested that the precipitation behavior of the alloys with different Ni content was similar. It should be mentioned that the applied homogenization annealing provided L1 2 -Al 3 (Sc,Zr) dispersoids with a size of about 10 nm that is similar to the size of precipitates formed at low temperature annealing [ 43 ]. We also suggest that Si atoms partially substitute Al in L1 2 phase providing a more complex dispersoids of (Al,Si) 3 (Sc,Zr) phase as it was demonstrated in Refs.…”

“…The heat treatment of as-cast material plays the most important role for the dispersoid strengthening and grain boundary pinning effect. The high density of fine L1 2 -strucutred Sc- and Zr-bearing dispersoids is observed after low temperature annealing [ 43 , 62 , 63 , 64 , 65 ] and two-step annealing regimes [ 43 , 56 , 63 , 65 , 66 , 67 ]. The homogenization annealing for the studied alloys was performed in two steps, with the first low-temperature step at 350 °C for 8 h and the second high-temperature step at 480 °C for 3 h to provide precipitation of the L1 2 dispersoids and fragmentation and spheroidization of the Al 3 Ni particles [ 29 , 52 ].…”

“…Sc and Zr provide the formation of a high density core-shell L1 2 -strucured Al 3 (Sc,Zr) dispersoids [ 39 , 40 , 41 ]. These dispersoids result in strong Zener pining effect and inhibit grain growth, and, in addition, increase tensile properties at room temperature [ 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. In novel alloys, the additions of Sc, as an expensive element, are reduced to 0.1 wt.%, while that of Zr is retained in a higher amount, 0.2 wt.% [ 32 , 49 , 50 ].…”