Abstract
The present study was undertaken to investigate the effects of some grain refining elements on the microstructure, macrostructure and tensile properties of Al-10Mg alloy (A520). The different master alloys used in this research were: Al-7Zr, Al-6Ti, Al-4B and Al-5Ti-1B. The results showed that the additions for best grain refinement were 4(.)5 wt-%Al-7Zr (0(.)3 wt-%Zr), 6 wt-%Al-6Ti (0-4 wt-%Ti), 7(.)7 wt-%Al-4B (0(.)3 wt%B) and 2 wt-%Al-5Ti-1B (0.1 wt-%Ti). The optimum amount for each grain refining material was selected as 3, 3, 5 and 2 wt-% for tensile test studies. The tensile strength of 190 MPa (average) was found to be increased to a maximum of 290 MPa (average) for samples refined with 2 wt-%Al-5Ti-1B. The elongation was increased from 4% to a maximum of 18% when refined with Al-7Zr. SEM fractography of the fractured face of high tensile specimens showed a minimum of shrinkage porosity and oxide films. (C) 2004 W. S. Maney Son Ltd.