The effect of energy density on texture and mechanical anisotropy in selective laser melted Inconel 718

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.

Keywords

• Energy density
• Selective laser melting
• Texture
• Taylor factor