The study examines the geometric behavior of corrosion-resistant steel components manufactured using the DMLS (Direct Metal Laser Sintering) process after various post-treatment methods. Full-surface 3D optical scanning was used to evaluate geometric deviations before and after three different treatments: stress relief heat treatment, immediate base plate removal, and natural aging. The results showed that heat treatment amplified the distortions caused by existing residual stresses, with elliptical deformation nearly doubling (i.e., deteriorating by approximately 200 %). Immediate removal resulted in asymmetrical, teardrop-shaped distortion that exceeded the ±0.1 mm tolerance limit. Natural aging effectively stabilized the geometry, with circularity deviation remaining within the ±0.1 mm limit. The results highlight the critical role of thermal management and post-processing in ensuring the dimensional accuracy of DMLS parts. The research demonstrates the advantages of full-surface, high-precision optical metrology in the detailed analysis of shape changes occurring during additive manufacturing, with the maximum permissible error of the measuring system limited to 0.01 mm in our measurements.

Residual stresses are one of the main challenges in metal additive manufacturing, particularly in direct metal laser sintering (DMLS). These stresses often lead to deformation once parts are removed from the build plate. In this study, we investigated the causal relationship between internal stresses and deformation behavior using a specially designed twin-cantilever geometry. This setup allowed parallel evaluation of different stress-relief treatments on a single component while minimizing cross-effects. High-precision optical 3D scanning was used to measure full-surface deformations before and after support removal and stress-relief heat treatment. The 1.2709 maraging steel (X3NiCoMoTi18-9-5) specimens were produced using a DMLS process with standard parameters, and stress-relief annealing was performed at 600 °C for 24 h. Results show that the heat treatment significantly reduced distortion on the supported side of the parts, with changes under 5%, while unsupported regions showed increased deformation, exceeding 60% in some cases. This indicates that internal stresses remain largely intact during heating and can further distort softened material if not mechanically constrained. The study confirms the critical role of constraint during heat treatment and demonstrates that optical metrology offers a reliable method to evaluate deformation trends. The results provide important insights into stress management strategies for DMLS parts and highlight the limitations of thermal relief in unconstrained geometries.