Strengthening of additively manufactured tungsten by use of hydrogen in argon shielding gas

Kemnitz, Ryan A.; Eckley, Cayla C.; Sexton, Brianna M.; LeSieur, Alex R.

doi:10.1016/j.ijrmhm.2022.105970

Cited by 6 publications

(2 citation statements)

References 14 publications

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“…One cylindrical specimen, 15 mm in diameter and 5 mm in height, was produced for each laser scan speed of 100, 200, 400, and 800 mm/s. All cylindrical specimens were printed on copper substrates with a 0.5 mm offset at an initial scan speed of 800 mm/s as described in Eckley et al [ 10 ] and Kemnitz et al [ 8 ]. Wire electrical discharge machining was used to remove the specimens from the substrate and produce two identical cross-sectional surfaces, each with a thickness of roughly 2 mm, at each scan speed.…”

Section: Methodsmentioning

confidence: 99%

“…In comparison to traditional manufacturing techniques, AM allows for the production of complex three-dimensional components in a manner that is more time, material, and cost-effective, but refractory metals, such as molybdenum, offer challenges due to their high melting points and ductile-to-brittle transition temperatures (DBTT) [ 8 ]. Oxygen impurities can increase the DBTT and the susceptibility of the consolidated material to cracking [ 9 ].…”

Section: Introductionmentioning

confidence: 99%

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Laser Powder Bed Fusion of Molybdenum and Mo-0.1SiC Studied by Positron Annihilation Lifetime Spectroscopy and Electron Backscatter Diffraction Methods

et al. 2023

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Positron annihilation lifetime spectroscopy (PALS) has been used for the first time to investigate the microstructure of additively manufactured molybdenum. Despite the wide applicability of positron annihilation spectroscopy techniques to the defect analysis of metals, they have only been used sparingly to monitor the microstructural evolution of additively manufactured metals. Molybdenum and molybdenum with a dilute addition (0.1 wt%) of nano-sized silicon carbide, prepared via laser powder bed fusion (LPBF) at four different scan speeds: 100, 200, 400, and 800 mm/s, were studied by PALS and compared with electron backscatter diffraction analysis. The aim of this study was to clarify the extent to which PALS can be used to identify microstructural changes resulting from varying LPBF process parameters. Grain sizes and misorientation results do not correlate with positron lifetimes indicating the positrons are sampling regions within the grains. Positron annihilation spectroscopy identified the presence of dislocations and nano-voids not revealed through electron microscopy techniques and correlated with the findings of SiO2 nanoparticles in the samples prepared with silicon carbide. The comparison of results indicates the usefulness of positron techniques to characterize nano-structure in additively manufactured metals due to the significant increase in atomic-level information.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%