On the aluminum-tantalum system

Experimental study and thermodynamic re-assessment of the binary Al–Ta system

“…Finally, our own experiments with several as-cast and annealed Al-Ta alloys do not confirm the eutectic-type phase diagram proposed in [13,19,20,23]. A phase diagram with a cascade of invariant peritectic reactions seems to be more appropriate, as the one proposed in [14] and later accepted in the handbooks [15] and [16].…”

“…In literature there are some rather different versions of the phase diagram constructed by authors substantially basing on own experimental results [14,18,20,23] and also using only assessed data [12,13,15,16]. The most recent phase diagram proposed by Du and Schmid-Fetzer [13] in 1996 (see Fig.…”

“…In [19] the sample Al-64.2 at.% Ta annealed at w1510 K was shown in the two-phase field f þ s, while in [14] the alloy Al-60.1 at.% Ta was single-phase s after annealing at both 1423 and 1673 K for 500 and 100 h, respectively. It should be noted that according to XRD analysis [20] the as-cast alloy Al-50 at.% Ta was single-phase s. The temperature of the peritectic reaction L p þ b 4 s was reported to be about 2373 [44] or 2273 K [23].…”

“…EPMA data of [5] fell within an interval of 24.5 AE 0.5 at.% Ta. In the literature there are both variants of melting for the 3-phase, congruent at 1823 [23] or 1900 K [20] and peritectic at 1773 [44] or 1824 K [14].…”

Interfacial reactions and phase equilibria in the Al-Cu/Ta systems

“…4-7 Kimura et al 5 first determined the phase Al 3 Ta to have ah omogeneity range extending from 23at.%Ta to 32at.%Ta. Schuster 6 reported that phase Al 3 Ta was aline compound and the alloys with the tantalum contents between 25 and 43 at.% contained two phase mixtures of Al 3 Ta and Al 3 Ta 2 .Subramanian et al 7 also proposed that the phase Al 3 Ta was aline compound and the alloys between 25 at.% Ta and 33 at.% Ta were two-phase mixtures of Al 3 Ta and Al 2 Ta.…”