Phase equilibrium and martensitic transformation in near equiatomic Ti Pd alloys

Solidus surface of the Al–Ti–Pd system in the Al–AlPd–TiPd–Ti region

“…The assumption [9] that there is a second-order phase transition in the Ti-Pd system between β-Ti and TiPd at subsolidus temperatures has not been confirmed. We assume that this transition occurs at temperatures somewhat lower than subsolidus, especially because the study [9] was conducted at 1000°C, which is 300°C lower than the solidus temperature (1310°C).…”

“…We assume that this transition occurs at temperatures somewhat lower than subsolidus, especially because the study [9] was conducted at 1000°C, which is 300°C lower than the solidus temperature (1310°C). Hence, we believe that there is a two-phase region at subsolidus temperatures, possibly in a very narrow temperature and composition range.…”

“…[8], there are a TiPd equiatomic phase (1400°C), whose high-temperature modification is isostructural to the above-mentioned AlPd phase, and a solid solution based on β-Ti (1310°C) with a narrow twophase region between them up to 50 at.% Pd in the Ti-Pd system at subsolidus temperatures. The more recent paper [9] employing the method of diffusion couples at 1000°C assumes a second-order A2/B2 transformation instead of the two-phase region between the phases.…”

Investigation of the Al–Ti–Pd alloy system at 930 and 1100°C

“…The literature data are given with the corresponding references. (8) 0.82438 (9) Al45.0Ti32.3Pd22.7 0.51454 (9) 0.82446 (10) Al43.5Ti34.1Pd22. 4 3 P63/mcm Nb(Ir,Al)2 0.89198 (3) 0.82040(4) Al41.0Ti34.5Pt24.5 [3] 0.89098 (11) 0.82011 (7) Al44.1Ti29.9Pd26.0 contains the so-called -phases stable below 792 • C [4], and the ␥-and -phases formed by solid-state reactions at still lower temperatures.…”

Morphology and Crystallography of Martensite Plate with Long Period Stacking Structure in Ti-Pd Shape Memory Alloy

“…5) However, there is still a lack of sufficient information about the phase equilibrium in nearequiatomic Ti-Pd alloy, especially in the high temperature region above 1273 K. We therefore investigated specimens quenched above 1273 K to obtain the microstructural aspects at high temperatures. As a result of microstructural observations at room temperature, we fortuitously discovered a martensitic phase with a long period stacking structure in near-equiatomic Ti-Pd alloys quenched at temperatures above 1373 K. The martensite with a long period stacking structure in the Ti-Pd binary system has not been reported so far.…”