Effects of Zr, Ti and B on structure and tensile properties of Al–10Mg alloy (A520)

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.