Effect of Al–5Ti–1B grain refiner on microstructure and properties of arc-additive-manufactured Al–Mg alloy. (June 2022)

• Record Type: Journal Article
• Authors: Wang, Liwei; Wu, Tao; Liu, Aiping; Yan, Huan; Mao, Yaning; Liu, Ying; Peng, Zhenzhen; Wang, Dianlong; Liang, Zhimin; Wang, Qian; Yang, Guang; Narayanaswamy, Balaji
• Is Part Of: Vacuum. Volume 200(2022)
• Publication Date: 2022-06
• Subjects: Additive manufacturing -- Microstructure -- Al–5Ti–1B -- Grain refinement -- Mechanical properties; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2022.111012
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: In this study, a strip-shaped Al–5Ti–1B grain refiner was employed to produce Al–Mg alloy using cold metal transfer arc additive manufacturing. The microstructure and mechanical properties of the straight-wall samples (SWSs) were analyzed. The results indicated that the Al3 Ti phase occurred in SWS with Al–5Ti–1B, and acted as heterogeneous nucleation sites during solidification. Formation of Al3 Ti particles led to the transformation of the columnar grains between the layers into equiaxed grains and refined the grains at the center of the layers. Furthermore, the Al3 Ti particles increased the fraction of low-angle grain boundaries by 8.2%. In addition, the anisotropy in mechanical properties (i.e. tensile strength and elongation) was reduced significantly. Also, the low hardness zone between the layers was eliminated. Thereby, improving the mechanical properties of the additive-manufactured Al–Mg alloy samples. Highlights: Al3 Ti was formed in CMT arc AM 5356 aluminum alloy samples with Al–5Ti–1B added. The microstructure of layer center was refined, and columnar-to-equiaxed transition occurred between the layers with addition of Al–5Ti–1B. The addition of Al–5Ti–1B resulted in the higher UTS and elongation in both the horizontal and vertical directions. Micro-hardness was more evenly distributed. The microstructure of CMT arc AM 5356 aluminum alloy specimens with Al–5Ti–1B exhibited isotropic mechanical properties.