Phase relations of Al-4Mg-Sc-Zr quaternary system in Al-rich range at 430℃
(School of Materials Science and Engineering,
Central South University, Changsha 410083, China)
Central South University, Changsha 410083, China)
Abstract: The 430℃ isothermal section of the Al-4Mg-Sc-Zr quaternary system in the Al-rich range was determined by means of equilibrium alloys with the use of microstructure, X-ray diffraction analysis and electron probe microanalysis. There coexist three single-phase fields, two two-phase fields and one three-phase field. It is established that the phase Al3Sc1-0.5Zr0-0.5 with L12 structure and Al3Zr1-0.8Sc0-0.2 with DO23 structure are in equilibrium with the α solid solution, Zr being dissolved in Al3Sc, further substituting for about 50% Sc(mole fraction) whilst Sc is present in the phase Al3Zr and the maximum substitution for Zr is about 20%.
Key words: Al-4Mg-Sc-Zr phase diagram; isothermal section;intermetallis compound