Metallographic Methods for Oxide Skin Segregation Studies

Abstract:

Article Preview

This work is a study of the segregation of alloying elements and salts to the surface of Direct Chilled-cast (DC-cast) ingots of alloy: (i) AA5083; and (ii) AA5182. The ingots only have slightly different chemical compositions. Alloy AA5182 contains Cu, while alloy AA5083 is grain refined, contains Cr, and is lower in Si and Fe compared to AA5182. The ingot microstructures were investigated using Optical Microscopy, Scanning Electron Microscope (SEM) and Secondary Ion Mass Spectrometry (SIMS). The results showed that the surfaces contained aluminum dendrites, large intermetallic crystals (Al6(MnFe) and Al3(Fe,Mn)) and impurities, and small crystals between dendrite arms. Between the dendrites small salt crystals containing Na, K, Ca, Mg, F and/or Cl were found. The conclusion is that salt and minority impurities are mainly located to grain boundaries in the segregation zone.

Info:

Periodical:

Materials Science Forum (Volumes 794-796)

Edited by:

Knut Marthinsen, Bjørn Holmedal and Yanjun Li

Pages:

51-56

DOI:

10.4028/www.scientific.net/MSF.794-796.51

Citation:

C. J. Simensen et al., "Metallographic Methods for Oxide Skin Segregation Studies", Materials Science Forum, Vols. 794-796, pp. 51-56, 2014

Online since:

June 2014

Export:

Price:

$38.00

* - Corresponding Author

[1] L. Bäckerud, E. Król and J. Tamminen: Solidification Characteristics of Aluminium Alloys, Universitetsforlaget AS, Oslo (1986).

[2] L.F. Mondolfo: Manganese in Aluminium Alloys, The Manganese Centre, France, ISBN 2 901109-01-2.

[3] L.F. Mondolfo: Aluminium Alloys; structure and properties, Butterworths, London, (1976).

[4] C. J. Simensen and U. Södervall: Investigation of trace elements in an Al-4. 8wt%Mg-0. 3wt%Mn alloy", "Surface and interface analysis, 30 (2000) 309-314.

DOI: 10.1002/1096-9918(200008)30:1<309::aid-sia806>3.0.co;2-y

[5] C. J. Simensen and U. Södervall: Quantitative analysis of aluminium alloys using SIMS, Z. Metallkunde 93 (2002) 322-329.

DOI: 10.3139/146.020322

In order to see related information, you need to Login.