Residual Stresses in CuSn10 Structures: A Macroscopic Investigation of Scan Strategies and Heat Treatments

To address the challenges of stress-induced distortion in additive manufacturing via laser powder bed fusion of CuSn10, the effects of different scanning strategies (cross-scan vs. island strategy) and various heat treatments (200°C, 300°C, 700°C) were analyzed regarding their effectiveness in reducing stress, as well as their impact on microstructure and hardness. The results indicate that the island strategy leads to higher values compared to the cross-scan strategy. A stress-relief annealing at 200°C for 2 h significantly reduced the bending strain by 83%, while 300°C for 2 h achieved almost complete stress relief of 96%. However, both treatments affected the material’s strength. A solution-annealing treatment at 700°C reduced distortion by approximately 90% and resulted in a pronounced microstructural evolution accompanied by a notable decrease in hardness. Overall, this study demonstrates that using continuous scanning vectors (cross-scan) yields lower stresses for CuSn10. Furthermore, it shows that thermal post-treatment can effectively reduce residual stresses, although one must balance this effect against the associated changes in material properties.