The effect of energy density on texture and mechanical anisotropy in selective laser melted Inconel 718. (June 2020)

• Record Type: Journal Article
• Authors: Liu, S.Y.; Li, H.Q.; Qin, C.X.; Zong, R.; Fang, X.Y.
• Is Part Of: Materials & design. Volume 191(2020)
• Publication Date: 2020-06
• Subjects: Energy density -- Selective laser melting -- Texture -- Taylor factor; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2020.108642
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: Laser additive manufacturing offers a unique way of tuning microstructure to improve alloy properties with a high degree of freedom by modifying the process parameters such as energy density. This work focuses on the energy density dependence of texture anisotropy and mechanical properties processed by selective laser melting (SLM) of IN 718 superalloy at different laser scanning speeds. It was found that strong columnar grains and 〈001〉 fiber texture become insignificant due to insufficient epitaxial growth as energy density decreases. The discrepancies in Taylor factor distributions induced by texture anisotropy are mainly responsible for the difference in tensile mechanical properties for samples built at different orientations. High Taylor factors lead to the increased strength of diagonally built testing samples. In addition, grain refinement enhances the strengthening effect as energy density decreases. Graphical abstract: Unlabelled Image Highlights: Taylor factor may measure the degree of anisotropy in the mechanical properties. The highest strength occurs in diagonally built tensile samples due to texture effect. Increased energy density leads to more anisotropy in yielding strength. Grain refinement increases as laser energy density decreases.