Heat-affected coarsening of β grain in titanium alloy during laser directed energy deposition. (December 2021)

• Record Type: Journal Article
• Authors: Xue, Aitang; Lin, Xin; Wang, Lilin; Lu, Xufei; Ding, Hanlin; Huang, Weidong
• Is Part Of: Scripta materialia. Number 205(2021)
• Publication Date: 2021-12
• Subjects: Additive manufacturing -- Titanium alloy -- Grain refinement -- Grain coarsening -- Microstructure; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2021.114180
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: The heat-affected coarsening of β-grains in titanium alloy produced by additive manufacturing (AM), which would be important for the achievement of fine β-grain like forging, was completely neglected in the past. Here, we reported that the significant coarsening of equiaxed β-grain of Ti6Al4V happened under the instantaneous high-temperature (above β-transus) thermal cycling during laser directed energy deposition process. Especially, the coarsening becomes more striking in the cases of smaller initial β-grain, larger energy density and higher preheating-temperature. Meanwhile, a modified model used to predict the size of the coarsened β-grain of AM titanium alloy was proposed. These findings provide a more comprehensive understanding of the β-grains of AM titanium alloy and a significant guidance for the composition design of AM titanium alloy with fine equiaxed β-grains. Graphical abstract: Image, graphical abstract