Papers by Keyword: TiAl Based Alloy

Abstract: The paper characterized the phase composition, microstructure and selected mechanical properties at room temperature and at temperature corresponding to the expected operating conditions of a new generation of TiAl based alloys melted in a vacuum induction furnace in a special graphite crucibles.

Abstract: In this paper, the bottom pouring vacuum suction casting is used, and the TiAl-based alloy blade with good face quality was obtained. Bottom pouring vacuum suction casting obtained Ti-47Al-5Nb-0.5Si alloy fine structure, the average grain size is 20um or less. Metal permanent forced cooling effect increases the undercooling degree, and the formation of Ti5Si3 can hinder the grain growth and the formation of nucleation particles, and Nb elements are conducive to the formation of B2 phase, and these three reasons refined the grain size.

Abstract: The corrosion behavior of porous Nb-containing TiAl based alloys in HCl, NaOH and NH₃H₂O aqueous solutions with various concentrations has been studied simultaneously at room temperature. The results indicate that the porous alloys have good acidic resistance which is probably based on the combined work of Ti-Ti metallic bond and covalent bond. And pitting corrosion is the main corrosion behavior of Nb-free TiAl alloys during the first 40 hours, while intergranular corrosion is the main corrosion behavior later. Nb-containing alloys have better acid corrosion resistance due to inhibiting intergranular corrosion by Nb element. In addition, the porous TiAl based alloys are much more resistant to corrosion in alkaline solutions than in acidic solutions, owing to the different oxide films formed in alkalis solutions.