SEARCH · Engineering Papers
Results for “WELDING”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Nondestructive ultrasonic characterization of a triple-weld-bead wire arc additively manufactured ER70S-6 S-curved wall
Understanding build-scale microstructural variation in wire arc additive manufacturing (WAAM) of low-carbon steels is essential for ensuring consistent structure–property relationships throughout large components. Conventional destructive characterization techniques, such as scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD), are time-intensive and limited to localized regions, making comprehensive evaluation of large WAAM structures challenging. In this study, a nondestructive ultrasonic approach was employed to characterize a 252 mm tall ER70S-6 S-curved WAAM wall produced using a triple-bead deposition strategy. Optical and SEM analysis revealed a repeating dual-region microstructure consisting of uniform polygonal ferrite at melt pool centers and heterogeneous ferrite with coarse and fine grains near melt pool boundaries, attributed to cyclic thermal conditions. Longitudinal ultrasonic backscatter imaging was used to evaluate the continuity of this periodicity along the full build height. The ultrasonic response exhibited a consistent repeating pattern that correlated with the observed layer-wise microstructural variation. X-ray computed tomography confirmed the absence of detectable porosity, indicating that ultrasonic contrast is primarily governed by grain morphology. Overall, the results indicate that longitudinal backscatter ultrasound is a promising nondestructive characterization technique for validating microstructural variations along the s-curved WAAM wall, with significant potential for microstructure optimization and process control.
Joining aluminum alloy to ultrahigh-strength boron steel through an impact welding approach
Not Available
Material flow visualization during friction stir welding using high-speed X-ray imaging
Not Available
Property mapping of friction stir welded Al-2139 T8 plate using site specific shear punch testing
Not Available
Effect of supercritical CO2 on the performance of 740H fusion welds
Not Available
Processing-microstructure-property correlations for temperature-controlled friction stir welding of 304L SS plates
Not Available
Oxidation behavior of welded Zry-3, Zry-4, and Zr–1Nb tubes
Not Available
Effect of laser mode on microstructure and corrosion resistance of 316L stainless steel weld joint
Not Available
Role of cavities on deformation-induced martensitic transformation pathways in a laser-welded, neutron irradiated austenitic stainless steel
Not Available
Qualification of laser-weld interconnection of aluminum foil to back-contact silicon solar cells
Not provided.