Microstructure and Performance Studies of a Novel Cobalt High Entropy Alloy
Bibliographic record
Abstract
A novel high entropy alloy (HEA), designated as HE6, is created by combining the features of HEAs and Stellite alloys in this research. The new alloy has the equiatomic Co-Cr-Fe-Ni composition (22 at.%) with a large amount of W (19 wt.%), small amounts of C (0.96 wt.%) and Mo (3 wt.%). The bulk specimens of HE6 alloy are fabricated from the alloy powder via spark plasma sintering (SPS) and plasma transferred arc (PTA) welding processes. The microstructures of the SPS and PTA specimens are studied using a scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDX) and using X-ray diffraction (XRD). A series of material characterization tests such as hardness, wear and corrosion are performed on the bulk HE6 specimens. As the benchmark of Stellite alloy family, Stellite 6 is investigated along with HE6 for comparison. It is found that HE6 alloy has a microstructure which is similar to that of Stellite alloys where various carbides and intermetallics are embedded in a solid solution matrix, but compared to Stellite 6, the FCC solid solution of HE6 consists of multi-element structures (Co, Cr, Fe and Ni), not single FCC Co structure, and also, the carbides and intermetallics in HE6 alloy are more diverse. The hardness and dry-sliding wear tests show that HE6 alloy does not perform as well as Stellite 6. In the electrochemical and immersion corrosion tests, similar to Stellite alloys, HE6 alloy displays passivation ability by forming protective Cr-rich oxide films in 3.5% NaCl, 2% HCl and 10% H2SO4 solutions, but localized corrosion (pitting) can occur when the oxide films are broken. HE6 alloy shows less resistance to corrosion under the electrochemical impedance spectroscopy (EIS) and cyclic polarization tests than Stellite 6, but has lower corrosion rates under immersion test in 5% HCl and 10% H2SO4 solutions for the longer testing duration (72 hours), also showing nearly stable corrosion rate with testing time, which indicates better repairing ability of the oxide films.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 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".