The 800 K isothermal section of the Y–Al–Sb phase diagram

Experimental investigation of the Al–Y phase diagram

“…Based on the observation that alloys richer in Y than the eutectic composition contain both ␣Al 3 Y and ␤Al 3 Y, Snyder [5] suggested that the transformation temperature is quite close to the eutectic temperature. The existence of two polymorphic forms of Al 3 Y has been confirmed by Snyder [5] and Bailey [15] for ␣Al 3 Y and by Snyder [5], Bruzzone and Ruggiero [16], van Vucht and Buschow [17], Sands et al [18], Dagerhamn and Westman [19] and Zeng and Wang [12] for ␤Al 3 Y.…”

“…In order to verify its existence, Zeng and Wang [12] prepared several binary Al-Y alloys within the composition range of 62.5-67 at.% Y when they established the 527 • C isothermal section of the Al-Sb-Y system. Their samples were annealed at 900 • C for 500 h in an evacuated quartz tube, cooled to 527 • C at a rate of 10 K/h, and then annealed at 527 • C for 200 h. The XRD examinations of these samples show no existence of Al 3 Y 5 and AlY 2 but the occurrence of Al 2 Y 3 and AlY 3 .…”

“…Subsequent investigators Dagerhamn [13] as well as Zeng and Wang [12] proposed AlY 3 as the most Y-rich compound. Dagerhamn [13] mentioned that equilibrium conditions were not reached in their annealed samples.…”

“…Dagerhamn [13] mentioned that equilibrium conditions were not reached in their annealed samples. In the work of Zeng and Wang [12], the alloys used to verify the existence of AlY 3 were annealed at 527 • C for 200 h. At such a low temperature, true equilibrium is most likely not reached.…”

Investigation of the interaction of the components in the Y–Si–Sb system at 670 K

“…The Y-Si-Sb ternary system has not been studied over the full concentration region. Among the M-X-Sb and related ternary systems (RE = rare earth elements, X = Al, Ga, Si, Ge), only for Y-Al-Sb [1], Ce-{Si,Ge}-Sb [2], Dy-Si-Sb [3] and Ti-{Si,Ge}-{Sb,Bi} [4][5][6] phase diagrams were reported. The existence of 'pseudobinary' compounds formed by substitution in the Zr 5 (Al,Ga,In) 3−x Sb x , Ti 5 Ga 3−x Sb x and Hf 5 In 3−x Sb x systems (x =∼1.5) [7] and Sc 5 Al 3−x Sb x (x = 0.5-2.75), Sc 5 Ga 3−x Sb x (x = 0-2.35) [8] were investigated as a possible way to enhance oxidative resistance and stability.…”