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Insights into elevated temperature tensile deformation mechanisms and kink banding in additively manufactured tungsten

Mayes, Riley [ORNL] (ORCID:000900089307010X)·Estrada, Katie [ORNL] (ORCID:0009000912768109)·Luna Falcon, Pablo [ORNL]·Holtham, Noah [ORNL] (ORCID:0000000289288375)·Thapliyal, Saket [ORNL] (ORCID:0000000162415904)·Fernandez-Zelaia, Patxi [ORNL]·Ledford, Christopher [ORNL] (ORCID:0000000316843857)·Kato, Yutai [ORNL] (ORCID:0000000194945862)·Kirka, Michael [ORNL] (ORCID:0000000249791240)
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Abstract

Additive manufacturing (AM) potentially enables fabrication and repair of plasma facing components (PFCs) of tungsten. However, deformation mechanisms in AM-fabricated tungsten under service-relevant thermomechanical conditions remain unknown majorly due to challenges in achieving crack-free W. This study reveals the deformation mechanisms operative under tension at 800 °C and 1200 °C in the electron beam melting powder bed fusion (EBM-PBF) fabricated W. Textured columnar grains with mixed <001 >/<111 >|| build-direction were observed. Strong anisotropy in tensile properties persisted across test temperatures, and all specimens exhibited extensive deformation-induced banding phenomena. Grain boundary character analysis of the deformed specimens indicated that these deformation bands were kink bands with tilt grain boundaries prominently present at the band-matrix interface. Interestingly, the material within the kink bands rotated toward higher resolved shear stress, providing insights into the origins of kink band formation in body-centered cubic refractory metals. Intragranular misorientation axis analysis revealed that plasticity was dominated by {110} <111 > slip at 800 °C, whereas additional (213)[11⁢̄1] and (112)[11⁢̄1] slip systems activated at 1200 °C. A dense low-angle boundary networks observed near fractured surface indicated the onset of dynamic recrystallization. Results reveal plasticity governing mechanisms in AM-fabricated W under power plant-relevant conditions, and provide insights into kink band attributes in refractory metals.

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Mayes, Riley [ORNL] (ORCID:000900089307010X), Estrada, Katie [ORNL] (ORCID:0009000912768109), Luna Falcon, Pablo [ORNL], Holtham, Noah [ORNL] (ORCID:0000000289288375), Thapliyal, Saket [ORNL] (ORCID:0000000162415904), Fernandez-Zelaia, Patxi [ORNL], Ledford, Christopher [ORNL] (ORCID:0000000316843857), Kato, Yutai [ORNL] (ORCID:0000000194945862), Kirka, Michael [ORNL] (ORCID:0000000249791240). 2026-08-01. Insights into elevated temperature tensile deformation mechanisms and kink banding in additively manufactured tungsten. https://doi.org/10.1016/j.jmrt.2026.08.119

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