Microstructure and properties of Ti-Fe-Y alloy fabricated by laser-aided direct metal deposition

摘要

Ti-Fe-Y alloys were designed using a "cluster-plus-glue-atom" model and then were prepared by laser-aided direct metal deposition (LDMD) on a pure titanium substrate. The influence of the Y addition on the microstructure and properties of the alloys were investigated. The results show that the alloys are composed of p-Ti solid solution and FeTi compound. The addition of Y not only suppresses the formation of Ti_4Fe_20 oxide but also increases the supercooling degree of the melt, leading to the grain refinement and the increase in the solid solution of the p-Ti. Meanwhile, the microstructure changes sequentially from eutectic to hypereutectic to hypoeutectic with the increasing of the Y addition. The strengest Ti-Fe-Y alloy has a dispersed eutectic structure and exhibits a good combination of mechanical, tribological, and forming properties, which is superior to that obtained for the binary Ti_(70.6)Fe_(29.4) eutectic alloy. This makes the alloy a promising candidate as a LDMD material.