Helical drilling of three-dimensional conical converging-diverging nozzle in steel using ultrashort laser pulses
Bibliographic record
Abstract
Three-dimensional conical converging-diverging nozzle typically a de Laval nozzle can be used for micropropulsion of microsatellites. The profile control, surface roughness and symmetry of the nozzle are key parameters to determine its performance. In this paper, we focus on the fabrication of a three-dimensional conical converging-diverging nozzle using helical drilling optics and ultrashort laser pulses. The helical optics makes it possible to dynamically control the profile of a hole by adapting the helical path during drilling process. An opening angle up to 18.6° on the converging part and 6.6° on the diverging part are achievable in 1 mm thick stainless steel by means of classic helical drilling. By introducing a dynamic helical process, the opening angle of converging part with straight profile can be extended to more than 90°. Moreover, the employment of an ultrashort pulsed laser has contributed to a high quality surface on the hole-wall having an average roughness less than 0.4 µm.
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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) | 0.000 | 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".