Improving component dimensional accuracy in electron beam powder bed fusion by addressing nonlinear deformations with 3D compensation strategies

Abstract

Electron beam powder bed fusion (EB-PBF) is effective for producing complex geometrical components with minimal residual stress because of elevated powder bed temperatures; however, it faces challenges in achieving dimensional accuracy due to nonlinear shrinkage. We systematically investigated the thermal shrinkage behaviour of large-scale EB-PBF components and developed 3D nonlinear compensation strategies. A thermal-mechanical model was developed to simulate residual stress and deformation during printing and cooling, revealing that nonlinear shrinkage is linked to thermal history, stress distribution, and material properties. The proposed method improved dimensional accuracy, reducing maximum errors from 1.81 mm to 0.16 mm, meeting industrial tolerances for components sized 77 × 48 × 326 mm. Hereafter, we developed a comprehensive digital workflow encompassing topology optimisation and compensation, validated through a case study on a topology-optimised satellite component. This approach enhances manufacturing precision and significantly reduces trial-and-error iterations in product design, resulting in substantial time and cost savings.

Keywords

• Additive manufacturing
• electron beam melting
• distortion compensation
• thermal shrinkage
• printing accuracy
• thermal-mechanical modelling