PHASE TRANSFORMATIONS IN RAPID SOLIDIFIED AL BASED

M. GALANO; F. AUDEBERT; I.C.STONE; B. CANTOR

Rio de Janeiro

Simposio; IMC17 - International Microscopy Congress; 2010

Nanoquasicrystalline Al-Fe-Cr-based alloys have a microstructure composed of quasi-spherical icosahedral quasicrystalline particles with sizes around 100 nm embedded in an fcc-Al matrix. These nanoquasicrystalline alloys have shown high strengths at elevated temperatures that makes them promising materials for applications in the automotive and aeronautical industries. In particular previous works by the authors [1,2] have shown that the Al-Fe-Cr-Ti alloys show a very good combination of strength and ductility. However, the metastability of the quasicrystalline phase can limit the use of these alloys at elevated temperatures. In the present work a thorough analysis on the microstructure and stability at different temperatures on Al-Fe-Cr-based nanoquasicrystalline alloys containing Ti, V, Nb or Ta was carried out. The microstructural evolution were analysed by means of X-Ray Diffraction, hot stage Transmission Electron Microscopy and chemical analysis by Energy Dispersive X-Ray Spectroscopy in a Scanning-Transmission Electron Microscope.These nanoquasicrystalline alloys have shown high strengths at elevated temperatures that makes them promising materials for applications in the automotive and aeronautical industries. In particular previous works by the authors [1,2] have shown that the Al-Fe-Cr-Ti alloys show a very good combination of strength and ductility. However, the metastability of the quasicrystalline phase can limit the use of these alloys at elevated temperatures. In the present work a thorough analysis on the microstructure and stability at different temperatures on Al-Fe-Cr-based nanoquasicrystalline alloys containing Ti, V, Nb or Ta was carried out. The microstructural evolution were analysed by means of X-Ray Diffraction, hot stage Transmission Electron Microscopy and chemical analysis by Energy Dispersive X-Ray Spectroscopy in a Scanning-Transmission Electron Microscope.