The purpose of this study is to evaluate the deformation behavior of 3D printed specimens using the small punch tensile test method. Traditional tensile tests for assessing mechanical properties require a significant amount of material to produce uniaxial tensile specimens. In contrast, the small punch test method only requires 10 x 10 x 0.5 mm (width x length x thickness) thin plate specimens, providing a substantial economic advantage in specimen sampling and production. This method is particularly beneficial when it is impossible to produce specimens of the same size as uniaxial specimens, as it allows tensile testing with just the minimum sample required. In this study, we utilized fused deposition modeling 3D printing and considered various 3D printing parameters, such as layer height and volume fraction, while manufacturing the specimens. We then compared and analyzed the effects of these variables on tensile strength as measured by the small punch tensile test. Furthermore, we focused on investigating the applicability of this method to the deformation behavior of 3D printed specimens. We also examined the impact of laminating conditions, including layer height, printing speed, and laminating direction, on the failure modes observed after the small punch tensile test.
In this research, the small punch (SP) test was applied to examine the local creep characteristics of a narrow gap weldment. To find the local creep property, an Ni-based 617 alloy and its narrow gap weldment. which is one of candidates for advanced fossil power plants, were employed. Thin square specimens were machined at three different locations: weld metal, base metal, and HAZ near the base metal from the Inconel 617 alloy narrow gap weldment. The results of the SPC test were evaluated. The microstructure of narrow gap weldment was observed by scanning electron microscopy and optical microscopy to investigate the effect of the microstructure on the creep properties of the weld zone. The creep rupture part of the weldment was observed by scanning electron microscopy. Finally, four different creep characteristics of the narrow gap weldment were obtained by the SPC test with good validity.