Crack‐Free Tungsten Fabricated via Laser Powder Bed Fusion Additive Manufacturing
Bibliographic record
Abstract
Abstract Additive manufacturing of tungsten (W) is challenging due to its high melting point, high thermal conductivity, oxidation tendency, and brittleness from grain boundary (GB) oxides. In this study, the processing of W through laser powder bed fusion is investigated. Parts are fabricated under argon (Ar) and nitrogen (N 2 ) atmospheres using the same processing parameters. The part produced in Ar has cracks with oxide precipitates decorating the fractured GBs. On the other hand, crack‐free W samples are produced under N 2 atmosphere without any additional process modification. In both cases, the oxygen (O) content in the LPBF samples is similar to the starting powder. Interestingly, the analysis of the samples fabricated in nitrogen suggests that nitrogen is retained beyond the equilibrium solid solubility limit, while high‐resolution electron micrographs of fractured surfaces reveal reduced levels of oxides at GBs. Increased hardness for samples processed under N 2 atmosphere is observed. Density Functional Theory (DFT) calculations performed to study the influence of interstitial nitrogen on oxygen diffusion in W indicated a hindrance to O diffusion from the presence of dissolved N.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".