ISSN:
1573-4889
Keywords:
aluminum-lithium alloys
;
oxidation
;
oxide nucleation
;
lateral oxide growth
;
secondary ion mass spectrometry
;
scanning ion microprobe
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The high-temperature oxidation behavior of binary Al-Li alloys has been characterized by scanning electron microscopy and secondary ion mass spectrometry in order to understand the mechanism of rapid oxidation in these alloys and to correlate the oxide morphology to its microchemistry. The oxide scale developed on polished specimens during short exposures in air at 530°C shows characteristic nodules that usually nucleate at grain boundaries. Examination of the alloy surface after removal of the oxide layer shows that the initial growth of the oxide nodules occurs laterally in addition to thickening normal to the oxide/alloy interface. Microchemical analysis of the oxide film with a scanning ion microprobe reveals a thick Li-oxide layer at the oxide/gas interface indicating preferential oxidation of Li at the free surface; the rest of the oxide film is composed of both Al- and Li-rich oxides, probably Li2O and LiAlO2 The presence of trace impurities (K, Na, F, and Cl) in the oxide scale was also detected. A microstructural model for the development of the oxide film in the Al-Li system is presented on the basis of both morphological and microanalytical data obtained in this study; this new model is compared with existing models.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01151586
Permalink