| Autor: |
Eric N. Coker, Burl Donaldson, Walter Gill, Nadir Yilmaz, Francisco M. Vigil |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
Applied Sciences, Vol 13, Iss 1, p 229 (2022) |
| Druh dokumentu: |
article |
| ISSN: |
2076-3417 |
| DOI: |
10.3390/app13010229 |
| Popis: |
The isothermal oxidation in air of high purity aluminum sheet was studied as a function of temperature using Thermogravimetric Analysis simultaneously with Differential Scanning Calorimetry (TGA/DSC). The rates and extents of oxidation were found to be non-linear functions of the temperature, in agreement with the literature. Between 650 °C and 750 °C very little oxidation took place; at 850 °C oxidation occurred after an induction period, while at 950 °C oxidation occurred without an induction period. At oxidation temperatures between 1050 °C and 1150 °C rapid passivation of the surface of the aluminum occurred, while at 1250 °C and above, an initial rapid mass increase was observed, followed by a more gradual increase in mass. The initial rapid increase in mass was accompanied by a significant exotherm, which was quantified by DSC. At temperatures of 1050 °C and above the specimen coalesced into a spheroidal particle, whereas at lower temperatures the original morphology was retained due to the cohesive strength of the native oxide layer. Cross-sections of oxidized specimens were characterized by scanning electron microscopy (SEM); the observed alumina skin thicknesses correlated qualitatively with the observed mass increases. Interrogation of the surface of an oxidized spheroidal particle by SEM showed a fractured alumina shell around a partially hollow core of aluminum which appeared to have grain boundaries. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
