激光增材制造Ti6Al4V-Inconel718功能梯度材料的成分变化和微观结构演变

Compositional Changes and Microstructure Evolution of Ti6Al4V-Inconel718 Functionally Graded Materials by Laser Additive Manufacturing

摘要:

利用激光增材制造技术制备了Ti6Al4V/Inconel718功能梯度材料,研究了该梯度材料的成分及相组成、显微组织和显微硬度的变化。研究表明：沿组成梯度方向发生了一系列相变：α+β→α+β+Ti₂Ni→β+TiNi→γ,过渡层主要是由TiNi和Ti₂Ni以及Ti-Cr和Ti-Fe等二元相组成的混合体；沿材料底部至顶部微观组织发生了由魏氏α片层组织到细小树枝晶的转变；对沉积结构进行显微硬度测试,发现具有较高Ti₂Ni相面积分数的过渡层最硬,本研究发现最大值为823HV。

Abstract:

Ti6Al4V/Inconel718 functionally graded materials were prepared by laser additive manufacturing technology. The composition, phase composition, microstructure and microhardness of the gradient materials were studied. The research shows that a series of phase transitions occur along the composition gradient direction: α+β→α+β+Ti₂Ni→β+TiNi→γ, and the transition layer is mainly composed of TiNi and Ti₂Ni and binary phases such as Ti-Cr and Ti-Fe. The composition of the mixture; the microstructure from the bottom to the top of the material has undergone a transformation from Widmanst?tten α-laths to fine dendritic structure; the microhardness test of the deposited structure shows that the transition layer with the higher Ti₂Ni phase area fraction is the hardest. This study found a maximum of 823 HV.