Design guidelines for suppressing distortion and buckling in metallic thin-wall structures built by powder-bed fusion additive manufacturing

Abstract

Controlling distortion in laser powder-bed fusion additive manufacturing is of critical importance especially for thin-wall structures, which typically experience significant deformation and buckling during the build process. We examine this issue from the perspective of design by systematically performing numerical simulations of the additive process of tubular components as a function of part design, including fillet radius, wall thickness, tube width and height. It is found that round corners, as opposed to sharp corners, suppress distortion even at small wall thickness (400 µm), while part width has a greater impact on distortion than part height. The buckling behavior of such structures is numerically investigated and analysis results show that for designs most prone to distortion, a critical height exists below which the component is distortion-free. The modeling was experimentally validated by manufacturing thin-wall components of IN718 alloy using the EOS M290 printer. The findings provide practical guidelines to manufacture metallic thin-wall tubular components with minimal to no distortion using powder-bed fusion additive manufacturing.

Keywords

• Design for additive manufacturing
• Distortion
• Modeling and simulation
• Design map