Phase Equilibria and Mechanical Properties in Multicomponent Al–Ni–X (X?=?Fe, Cr) Alloys

摘要

The present study reports the microstructure evolution in multicomponent Al–Ni–X (X?=?Fe, Cr) alloys. The X-ray diffraction characterization technique and electron microscope attached with energy-dispersive spectroscopic analysis have been used to understand the structural and microstructural evolution in the present multicomponent Al–Ni–X (X?=?Fe, Cr) alloys. Al~(98.6)Ni~(0.5)Fe~(0.9)alloy shows the presence of (Al)~(ss), Al~(3)Fe and Al~(9)FeNi phases. It is observed that the microstructure of Al–Ni–Fe alloy shows the existence of primary dendritic phase of (Al)~(ss)and two eutectics (i.e. globular eutectic: L?→?(Al)~(ss)?+?Al~(3)Fe and lamellar eutectic: L?→?(Al)~(ss)?+?Al~(9)FeNi). Al–Ni–Fe alloy shows superb compressive strength (~?200?MPa) and plasticity (~?70%) at room temperature, while the microstructure of multicomponent Al~(92)Ni~(4)Cr~(4)alloy exhibits?the presence of dendritic phases of Al~(7)Cr and Al~(3)Ni plus ternary eutectic (i.e. L?→?(Al)~(ss)?+?Al~(3)Ni?+?Al~(7)Cr). Al–Ni–Cr alloy shows good room temperature ultimate compressive strength (~?300?MPa) and plasticity (~?50%). It is important to note that there is no fracture during mechanical testing of investigated Al–Ni–X (X?=?Fe, Cr) alloys.