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A new type of composite layer material system, Al4Ni/Al2CrCuFeNi2Ti high-entropy alloy, was designed. The Al4Ni transition layer was prepared on the surface of an AZ91D magnesium alloy by laser cladding, which solves the problem of excessive melting point difference between the magnesium alloy and the high-entropy alloy. The Al4Ni/Al2CrCuFeNi2Ti high-entropy alloy composite layer with good surface formation was successfully prepared on the AZ91D magnesium matrix. Optical microscope, scanning electron microscope, and x-ray diffraction were used to characterize the microstructure and properties of the composite layer. It showed that the high-entropy alloy layer was mainly composed of simple BCC and FCC solid solution phases. The Al2CrCuFeNi2Ti high-entropy alloy layer, the Al4Ni layer, and the AZ91D magnesium matrix have excellent metallurgical bonds. The hardness of the high-entropy alloy layer was about 12 times that of the AZ91D magnesium alloy. The corrosion resistance of the high-entropy alloy layer in 3.5 wt. % NaCl was also improved. [ABSTRACT FROM AUTHOR]

Examines the microstructural evolution of an SmTM[sub7.3] alloy during different stages of heat treatment under a conventional scanning electron microscope. Microstructures of the alloy; Correlation between the coercivity and heat treatments; Evolution of the platelet phase, the zonal phase and the grain boundary phase during isothermal aging.

Tensile ductility of the Ti-based composites, which consist of a β-Ti phase surrounded by ultrafine structured intermetallics, is tunable through the control of intermetallics. The two Ti-based alloys studied exhibit similar compressive yield strength (about 1000MPa) and strain (about 35%-40%) but show a distinct difference in their tensile plasticity. The alloy Ti71.8Nb14.1Ni7.4Al6.7 fractures at the yield stress while the alloy Ti71.8Nb14.1Co7.4Al6.7 exhibits about 4.5% of tensile plastic deformation. To clarify the effect of microstructure on the deformation behavior of these alloys, tensile tests were carried out in the scanning electron microscope. It is shown that the distribution as well as the type of intermetallics affects the tensile ductility of the alloys. [ABSTRACT FROM AUTHOR]