Ti-6Al-4V 판재에 Vanadium의 레이저 고에너지 적층 경로에 따른 잔류응력 특성 = Residual Stress Characteristics According to the Tool Path of Vanadium on Ti-6Al-4V Plates in Laser Direct Energy Deposition

다국어 초록 (Multilingual Abstract)

Laser directed energy deposition (L-DED) has the advantages of complex shape production and easy stacking of dissimilar materials, but the reduction in residual stress owing to the rapid temperature change and difference in the thermal expansion behavior between materials should be considered. In this study, the residual stress characteristics according to the tool path in dissimilar materials of a Ti-6Al-4V plate and vanadium were compared and evaluated using finite element analysis. A vanadium layer was stacked on a Ti-6Al-4V plate using the L-DED method, and the simulation reliability was confirmed by comparing the temperatures under the same conditions. To compare the effect of the tool path on the residual stress, the zigzag path, spiral in-to-out (spiral IO), and spiral out-to-in (spiral OI) were simulated. Every path showed high residual stress in the outer area, and spiral IO had a low residual stress level and was uniform throughout the entire area. Therefore, the tool path when the outer area is stacked later similar to the spiral IO, was confirmed to be better for delamination and residual stress reduction. In the case of the zigzag path, the residual stress could be reduced on the final path, and the build-up speed was faster, but a high residual stress was generated on the starting path.