Constitution in the solid state of aluminum rich alloys in the Al-Mn-Cr ternary system

On the constitution of the Al-rich part of the Al–Cr–Mn system

“…14). This observation is in contrast to the results in [1,3] where the + Al 6 Mn + (Al) equilibrium was reported at this temperature. Long-term annealing (for 1490 h) was applied on either as-cast alloys, or those previously annealed at 560 • C for 1197 h, and the same results in both experiments were obtained.…”

“…10), apart from the above-mentioned phases, also the Al-Cr -phase is solid, while -Al 45 Cr 7 is only formed below 795 • C. The -phase range extends up to 9 at.% Mn. The compositional region of the -phase extends towards Al 3 Cr and achieves about the Al 75 Mn 3 Cr 22 composition. The T-phase is already unstable at this temperature.…”

“…The Al 12 (Mn,Cr) phase exhibited a compositional range along about constant Al concentration. At 550 • C, it was found to be in equilibrium not only with (Al), Al 6 Mn and the -phase but also with the -phase [2], while in [3] it was claimed that equilibrium between Al 12 (Mn,Cr) and the -phase was already present at 580 • C , i.e. only slightly below its formation temperature.…”

“…Also, a ternary eutectic reaction L ↔ (Al) + Al 6 Mn + was revealed in [1] at 657.7 • C. The (Al) solid solution was found to contain only a little Mn and Cr. The (Al), Al 6 Mn and phases forming in the eutectic reaction were reported to be in equilibrium down to ∼590 • C. At ∼590 • C a ternary Al 12 (Mn,Cr) phase (G-phase) was found to be formed inside the (Al)-Al 6 Mn-compositional triangle [1][2][3]. The Al 12 (Mn,Cr) phase exhibited a compositional range along about constant Al concentration.…”

Liquidus, solidus and reaction scheme of the Al-rich part of Al–Cr–Mn

“…The Al corner of the Al-Cr-Mn phase diagram earlier investigated in [1][2][3] was recently revised in [4]. The latter research concentrated on the determination of the isothermal sections in the compositional range of 60-100 at.% Al and the temperature range of 490-1010 • C. No ternary phases were revealed in the above-mentioned compositional range.…”