Microstructure and mechanical properties of borided CoCrFeNiAl0.25Ti0.5 high entropy alloy produced by powder metallurgy
| Autor: | Sakin Zeytin, Mustafa Sabri Gök, Ali Günen, Azmi Erdogan |
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| Přispěvatelé: | Mühendislik ve Doğa Bilimleri Fakültesi -- Metalurji ve Malzeme Mühendisliği Bölümü, Günen, Ali |
| Rok vydání: | 2021 |
| Předmět: |
Sintered samples
Fracture-toughness Powder metals Fracture toughness values Powder mixtures Cobalt alloys Entropy Chromium metallurgy Mechanical properties Borides Chromium Borides chemistry.chemical_compound Complex metals Fracture toughness Relative density Powder metallurgy Densification Iron alloys Ti Instrumentation Iron metallurgy Microstructure Work tool steel Multidisciplinary Surface hardness Nickel metallurgy Condensed Matter Physics Hardness Surfaces Coatings and Films High entropy alloy Silicides Materials science High-entropy alloys Iron Materials Science Diffusion kinetics Physics Applied Surface roughness Boride Titanium alloys Boron carbide Cobalt metallurgy Powder mixture Boriding Sodium compounds Behavior Titanium metallurgy CoCrFeNiAl0.25Ti0.5 Metallurgy Chromium alloys Nanoindentation Boriding process Microstructure and mechanical properties Aluminum alloys chemistry Aluminum metallurgy Nimonic Alloys |
| Zdroj: | VACUUM |
| Popis: | CoCrFeNiAl0.25Ti0.5 high entropy alloy alloys (HEA), produced by powder metallurgy were subjected to boriding to improve their mechanical properties. Sintering was carried out at 1200 degrees C for 2 h in Ar, and boriding was performed at 900, 1000 and 1100 degrees C for 2 h using a 90 wt% B4C + 10 wt% NaBF4 boriding powder mixture. Microstructures, densities, surface roughnesses, and mechanical properties (hardness, fracture toughness and nanoindentation responses) of the samples were investigated. FCC, BCC and sigma phases had been observed after sintering, whereas complex metal borides were formed on the surfaces after boriding. Relative density values were between 85% and 90%. Significant increases in surface hardness were observed after boriding due to formation of hard, silicide-free boride layers. The boride layer thickness and hardness increased with increasing boriding temperature. The elastic modulus of the surface of the sintered sample (47.07 GPa) increased with the boriding process to values in the range of 140-151 GPa. Fracture toughness values between 3.57 and 4.25 MPa m(1/2) were obtained in borided samples, and increasing the boriding temperature reduced the fracture toughness. |
| Databáze: | OpenAIRE |
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