Microstructural evolution in laser rapid forming of a graded titanium-nickel alloy

Abstract

The fabrication of near net shaping parts with functionally graded materials using laser rapid forming have been considered as a signification and promising technology. In this paper, a graded binary Titanium-Nickel alloy has been deposited using laser rapid forming from a blend of elemental Ti and Ni powders. A compositional gradient, from elemental Ti to Ti-23.2at%Ni, was achieved within a length of ∼25mm. The solidification behavior and the morphological evolution of Ti/Ni functionally graded material formed by a laser rapid forming process were investigated. a series of phase evolutions: α→α+β → α+β+Ti2Ni → β+Ti2Ni along the compositional gradient have occurred. Phase formation and microstructure evolution along the compositional gradient direction was analyzed.The fabrication of near net shaping parts with functionally graded materials using laser rapid forming have been considered as a signification and promising technology. In this paper, a graded binary Titanium-Nickel alloy has been deposited using laser rapid forming from a blend of elemental Ti and Ni powders. A compositional gradient, from elemental Ti to Ti-23.2at%Ni, was achieved within a length of ∼25mm. The solidification behavior and the morphological evolution of Ti/Ni functionally graded material formed by a laser rapid forming process were investigated. a series of phase evolutions: α→α+β → α+β+Ti2Ni → β+Ti2Ni along the compositional gradient have occurred. Phase formation and microstructure evolution along the compositional gradient direction was analyzed.