Investigation of the Al–Cr γ-range

An investigation of the Al–Cu–Cr phase diagram: Phase equilibria at 800–1000°C

“…The diagrams in Refs. [14][15][16] were consistent with the binary boundary constitutional diagrams just accepted from the literature, but meanwhile the Al-Cr and Al-Cu phase diagrams have been modified and new structures associated with several of their phases (see [17][18][19][20][21][22][23][24][25][26][27] and references therein).…”

“…By heating ␥ 2 transforms to ␥ 1 of the (probably) perfect ␥-brass structure. In binary alloys the temperature of this transition is above 1000 • C [18] but it seems to have a tendency to decrease with the increase of the Cu concentration, together with the significant decrease of the melting temperatures. No thermal effect associated with the ␥ 1 ↔ ␥ 2 transition was observed at high-Cu compositions.…”

“…A wide range of Al-Cr from about 58 to 70 at.% Al is occupied by a rhombohedrally distorted ␥-brass phase designated ␥ 2 [18]. The distortions are stronger at lower Al, where the split of the diffraction lines is easily recognized in the powder XRD patterns (see the strongest reflection in Fig.…”

“…Additionally, high-and lowtemperature structures associated with both Al 8 Cr 5 and Al 9 Cr 4 were discriminated. However, according to our recent work [18] the region including the Al 8 Cr 5 and Al 9 Cr 4 phases of Ref. [17] can be presented as continuous in composition and separated into a high-temperature sub-region (provisionally of the perfect ␥-brass structure) and a low-temperature sub-region (of a distorted ␥-brass).…”

Determination of the crystal structure of the ɛ phase in the Fe–Al system by high-temperature neutron diffraction

“…gbrass-type structures of the cubic Cu 5 Zn 8 -type (so-called g 1 brass) and the related rhombohedral Cr 5 Al 8 -type (so-called g 2 brass) are also known from other binary transition metal-aluminium systems. V 5 Al 8 has the cubic g 1 crystal structure [29], Cr 5 Al 8 occurs as hightemperature g 1 and low-temperature g 2 phase [12,[29][30][31][32][33][34][35], and in the Mn-Al system a rhombohedral g 2 type phase is observed at low temperatures [36] which transforms displacively to a W-type MnAl(h) high-temperature phase not belonging to the g brasses [37,38].…”