Factors Controlling Residual Stress Formation in Laser Powder Bed Fusion Components

Monday, October 20, 2025: 11:00 AM
Mr. Mohammad Rais Alfiansyah Taufiq , University of New South Wales, Sydney, NSW, Australia
Dr. Bernd Gludovatz , University of New South Wales, Sydney, NSW, Australia
Dr. Xiao Peng Li , University of New South Wales, Sydney, NSW, Australia
Prof. Jamie J Kruzic , University of New South Wales, Sydney, NSW, Australia
Residual stresses in laser powder bed fusion (LPBF) fabricated components can cause significant problems with part distortion and reduced mechanical properties. LPBF process parameters are usually selected to achieve high relative density and specific mechanical properties without much thought about their impact on residual stresses. LPBF process parameter choices are most often based on the volumetric laser energy density, which poorly correlates with cooling rate and residual stresses. Accordingly, this study aims to increase our understanding of how to control residual stresses when selecting LPBF parameters, which in turn can help avoid excessive part distortion and/or negative effects on mechanical properties such as fatigue crack growth resistance.

This study aims to increase our understanding of how to control residual stress when selecting LPBF parameters to help avoid excessive part distortion and negative effects on mechanical properties such as fatigue crack growth resistance. This study employed a bridge curvature technique to compare residual stress magnitudes in LPBF fabricated AlSi10Mg and Ti6Al4V materials when using a range of LPBF process parameters known to give high relative density and good mechanical properties. Measuring bridge sample distortion enables quick semi-quantitative assessments of the material's residual stress state.

Our findings demonstrate a strong positive correlation between solidification cooling rates and residual stress distortion (FLTt) in AlSi10Mg samples, highlighting the importance of precise thermal management during LPBF. We also found that the relative residual stress of AlSi10Mg samples could be predicted by the in-situ monitoring system photodiode intensity. While FLTt values were generally higher for Ti6Al4V compared to AlSi10Mg, there was less variability for different LPBF parameters. The study offers practical guidance for fine-tuning LPBF parameters in applications sensitive to residual stress, with the aim of striking a balance between density, microstructure, and residual stresses to achieve an optimal LPBF manufacturing process.

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