Sintering Behavior and Microstructure Development of Porous Silicon Nitride Ceramics Prepared in an Air Atmosphere Furnace
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Porous silicon nitride (Si 3 N 4 ) ceramics have been sintered in a conventional air atmosphere furnace at temperatures between 1500°C and 1700°C, with sintering additions of either 5 or 10 wt% yttria (Y 2 O 3 ). The use of a protective α‐Si 3 N 4 powder bed helps to prevent significant oxidation of the samples during sintering in air, keeping oxidation weight gains below 4 wt% (typically <2.5 wt%). This compares with more typical weight losses when sintering in nitrogen. Samples prepared with a protective α‐Si 3 N 4 powder bed exhibited sintered densities up to ∼89% of the theoretical, which was notably higher than for similar compositions prepared in a controlled nitrogen atmosphere (i.e., ∼70% of theoretical). Increased densification is proposed to arise from the formation of a thin SiO 2 surface layer on individual α‐Si 3 N 4 particles, through passive oxidation, which is expected to promote viscous‐flow densification at lower temperatures. The excess of SiO 2 , relative to the starting composition, is also reflected in the final phase assembly, with Si 2 N 2 O formed in addition to the transformation of α‐ to β‐Si 3 N 4 , when sintering above ∼1550°C. A Si 2 N 2 O gradient occurs, with the surface being approximately 80 vol% Si 2 N 2 O and the bulk predominantly Si 3 N 4 , for samples sintered at 1600°C and 1700°C. Conversely, Si 2 N 2 O is not observed in any measurable volume for similar samples sintered in nitrogen.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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 it