High-temperature oxidation of AZ91-0.3%Ca-0.1%Y alloy in air
| Autor: | Dong Bok Lee, Bong Sun You, Muhammad Ali Abro |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Vapor pressure Inorganic chemistry Alloy Evaporation Oxide chemistry.chemical_element 02 engineering and technology engineering.material chemistry.chemical_compound Materials Chemistry Magnesium 020502 materials Metallurgy technology industry and agriculture Metals and Alloys Y alloy Yttrium equipment and supplies 021001 nanoscience & nanotechnology Condensed Matter Physics 0205 materials engineering chemistry Mechanics of Materials engineering 0210 nano-technology Stoichiometry |
| Zdroj: | Metals and Materials International. 23:720-725 |
| ISSN: | 2005-4149 1598-9623 |
| Popis: | AZ91 magnesium alloys containing 0.3% Ca and 0.1% Y were cast, and their oxidation behavior was investigated between 425 and 600 °C in atmospheric air to examine roles of Ca and Y during oxidation. During casting, Ca formed Al2Ca particles intergranularly, and reduced the amount of Al12Mg17 particles, while most of yttrium existed as Al2Y particles inter- and intra-granularly in the alloy. The AZ91 alloy oxidized fast above 425 °C, leading to complete ignition. By contrast, AZ91-0.3Ca-0.1Y alloy oxidized very slowly up to 550 °C. Calcium, which is more active than Mg, preferentially oxidized to CaO at the surface of the MgO-rich oxide to suppress the oxidation, evaporation and diffusion of Mg during the initial oxidation stage. Such suppression was due to the quite low vapor pressure and high stoichiometry of CaO. Calcium also suppressed the formation of less oxidation-resistant Al12Mg17 through forming oxidation-resistant Al2Ca in the alloy from the initial oxidation stage. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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