Al-Ge-Ti: Phase equilibria and structural characterization of new ternary compounds

作者：Bittner Roland W; Guerth Matthias; Duarte Liliana I; Leinenbach Christian; Effenberger Herta S; Richter Klaus W^*

来源：Intermetallics, 2014, 53: 157-168.

DOI：10.1016/j.intermet.2014.05.003

• ternary alloy systems
• titanium aluminides
• phase diagrams
• phase identification
• crystallography

Phase equilibria of Al-Ge-Ti have been investigated using scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and differential thermal analysis (DTA). Partial isothermal sections at 400 degrees C, 520 degrees C and 1000 degrees C were obtained with focus on the titanium-poor part up to 50 at.% titanium. Three ternary compounds were found to exist. The compound Al3GeTi (tau(1)) crystallizes in an own structure type (P4/nmm, tP10). Two structurally closely related compounds were found at the composition Al-1 -xGe1+xTi: tau(2) (0.61 <= x <= 0.73), Al4Si3Zr3-type, I4(1)/amd, tI24 and tau(2)' (0.36 <= x <= 0.57), Si2Zr-type, Cmcm, oC12. DTA data were used to construct a ternary reaction scheme (Scheil diagram) up to approximately 1300 degrees C, a partial liquidus projection and two vertical sections, at 10 at.% Ti and at a constant Al:Ti ratio of 1:1. A total number of 12 ternary invariant reactions were identified.

• 出版日期2014-10