Failure dynamics of spherical and irregular shaped Ti splats deposited on sapphire by cold spray
Bibliographic record
Abstract
Abstract Single splats of commercially pure Ti are deposited onto sapphire by cold spray under two spray conditions to achieve different in-flight powder velocities. The powders used have two morphologies: spherical powder (SP), manufactured by plasma gas atomization, and irregular powder (IP), manufactured by the Armstrong process, with a coral-like morphology. The adhesion strength of the single splats is measured by splat adhesion testing. By use of a specialized in situ scratch tester, interface failure during splat adhesion testing is observed through the sapphire substrate. Particle velocity does not significantly influence the adhesion strength and failure mechanism of SP splats. After deposition, the SP splat has an interface pore in its center which acts as an initiation site for crack propagation during splat adhesion testing. After failure, a well bonded portion of Ti remains on the substrate in the shape of a ring. IP splats deposited at low velocity show similar, well adhering, rings on the surface in localized locations scattered throughout the interface. An increase in velocity for IP splats led to an increase in adhesion strength and a nearly continuous well adhering interface. The behaviour of IP splats is understood by electron channelling contrast images of cross-sections where low velocities resulted in little change in microstructure while high velocities led to a highly deformed microstructure at the interface.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 teacher head, 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".