Replacement with Each Other of Ti and Zr in the Intermetallics of Al-(Si-)Ti-Zr Alloys

摘要

The structures and compositions of Ti and Zr rich phases in ternary Al-Ti-Zr and quaternary Al-Si-Ti-Zr systems were investigated by energy dispersive spectroscopy and X-ray diffraction.The additions of Ti and Zr were changed.It was found that Ti and Zr can replace each other in the Ti and Zr rich phases of Al-(Si-)Ti-Zr alloys.Compositions of the phases have been measured as a function of Ti and Zr additions.The content of Ti(Zr) in the phases increases with its addition in the alloys.Besides,the increase of Ti content can result in a decrease of lattice parameters.Microhardness of the phases in Al-18Si-xTi-/Zr alloys changes with composition evolution.Moreover,the microhardness is higher than that of the intermetallics of ternary Al-Si-Ti and Al-Si-Zr alloys,due to the distortion of crystal structure caused by the replacement of Ti and Zr.