About this Abstract |
| Meeting |
MS&T26: Materials Science & Technology
|
| Symposium
|
Advances in Refractory High Entropy Alloys and Ceramics
|
| Presentation Title |
Nb-Regulated Selective Oxidation in Al–V–Cr–Zr Refractory High-Entropy Alloys fabricated via Powder Metallurgy |
| Author(s) |
Gyosik Youn, Byungmin Ahn |
| On-Site Speaker (Planned) |
Gyosik Youn |
| Abstract Scope |
Nb-controlled phase constitution and selective oxidation behavior were investigated in Al–V–Cr–Zr-based refractory high-entropy alloys processed by powder metallurgy. The alloys were fabricated by mechanical alloying, spark plasma sintering, and subsequent homogenization heat treatment. Nb addition produced a systematic change in the preferred oxidation pathway. Alloys with Nb contents up to 0.5 molar fraction primarily developed VCr-rich oxides, indicating preferential oxidation of the VCr-enriched constituent phase. At Nb = 0.75, this VCr-rich oxide was largely suppressed, while Zr oxide formation became dominant and was accompanied by local cracking and scale instability. Further Nb addition to Nb = 1 promoted the formation of an Nb-rich BCC phase, shifting the oxidation response toward Cr-rich oxide formation. These findings identify Nb as a key compositional variable for directing oxide selection in refractory high-entropy alloys. |