A CONFOCAL MICROSCOPY STUDY ON MICROSTRUCTURE OF AS-CAST AND HEAT-TREATED Al-Zn AND Al-Zn-Mg ALLOYS CONTAINING Sn.

M. C. Ise, A. R. Daud', M. Daud2, M. V. Ahmad' & S. R. Bakar3.

Abstract

A CONFOCAL MICROSCOPY STUDY ON MICROSTRUCTURE OF AS-CAST AND HEAT-TREATED Al-Zn AND Al-Zn-Mg ALLOYS CONTAINING Sn.

C. Ise, A. R. Daud', M. Daud², M. V. Ahmad' & S. R. Bakar³.

'School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Malaysia ²Malaysian Institute for Nuclear Technology Research (MINT), 43000 Kajang, Selangor Malaysia

³Science and Technology Research Institute for Defence (STRIDE), 50634 Kuala Lumpur, Malaysia

The effect of Sn addition on microstructures of Al-Zn and Al-Zn-Mg alloys was studied by confocal laser scanning microscopy. The micrographs obtained clearly showed the presence of precipitates in the Sn-containing alloys. The X-ray diffraction analysis indicated that the precipitates were whether in the form of an individual phase of b­Sn or intermetallic compound of Mg₂Sn or both, depending on Mg content in the alloys. The amount of the precipitates present in the alloys increases with the increase in Sn content. The shape of the precipitates have changed from irregular and dendritic forms for as-cast alloys to nodular form after the alloys were homogenized at 550 °C for 24 hours and followed by artificial aging at 150 oC for 3 hours.

*Corresponding author. Tel.: +6(03)-89213806; fax: +6(03)-89215415 E-mail: ard@pkrisc.cc.ukm.my (A. R. Daud)