کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1690703 | 1011273 | 2012 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Characterisation of oxide and hydroxide layers on technical aluminum materials using XPS Characterisation of oxide and hydroxide layers on technical aluminum materials using XPS](/preview/png/1690703.png)
Aluminum alloys are widely used as technical lightweight materials. For industrial applications, these materials often have to be bonded, e. g. welded or brazed. To get a metallic connection by brazing, the natural oxide layer on Al-materials, which is dense and has a high melting point, has to be eliminated. This layer can be influenced by the temperature and humidity in the surrounding atmosphere. Due to the nm-thickness of the layer, the analysis of its thickness and composition is challenging. An applicable method is X-ray photoelectron spectroscopy (XPS). The present investigation shows the applicability of XPS to estimate the oxide layer thickness as well as to distinguish between Al-hydroxide and Al-oxide phases. Finally, reasons for the differences in brazeability depending on the previous storage conditions are studied. It is shown, that a storage under condensation for 9 days causes an increase of the oxide layer thickness and an aggregation of water inside the pores of the hydroxide layer. This lowers significantly the brazeability of the material.
► XPS can be used very convenient to analyse the oxidation/hydration behavior of Al-surfaces.
► The binding energy spectra cannot be used to distinguish between Al-oxide and Al-hydroxide.
► But the ratio between the oxidic bound Al and O enables the differentiation between Al-oxide and Al-hydroxide.
► Al-hydroxide is available on all technical Al-surfaces.
► The storage under condensation decreases the brazeability of Al-materials.
Journal: Vacuum - Volume 86, Issue 9, 14 March 2012, Pages 1216–1219