Tensile Properties of a Cast Al-Si-Mg Alloy with Reduced Si Content and Cr Addition at High Temperature
- 48 Downloads
Tensile properties of an Al-Si-Mg casting alloy with reduced Si content and Cr addition were investigated at room and high temperatures. It was found that the studied alloy exhibits a remarkable performance up to 200 °C, with comparable or slightly higher strength than typical values for Al-Si-Mg-Cu alloys, commonly used for high-temperature applications, and good elongation. This is due to the choice of proper heat treatment and to the formation of dispersoids containing Cr during heat treatment, which are stable at the considered temperatures, as demonstrated by scanning and transmission electron microscopy (STEM) analysis. Interestingly, exposure to 300 °C during tensile tests enhanced an additional formation of dispersoids. It is believed that heating the material in T6 condition led to such observed dispersoids formation since precursors were already present in the Al matrix. This is not sufficient to avoid material softening at 300 °C, but it represents an interesting point in order to develop alternative heat treatment routes for dispersion-strengthened Al alloys.
KeywordsAl alloys dispersion strengthening heat treatment mechanical properties microstructure precipitation strengthening
The authors would like to thank Maxion Wheels Italia Srl for providing the alloy, F. Peli (Dept. of Mechanical and Industrial Engineering of the University of Brescia) for his support in tensile samples preparation and Dr. L. Montesano (Dept. of Mechanical and Industrial Engineering of the University of Brescia) for SEM analysis.
- 9.J.R. Davis, Ed., ASM Speciality Handbook, Aluminum and Aluminum Alloys, ASM International, Davis & Associates, Materials Park, 1993Google Scholar
- 34.M. Tocci, A. Pola, L. Raza, L. Armellin, and U. Afeltra, Optimization of Heat Treatment Parameters for a Non-conventional Al-Si-Mg Alloy with Cr Addition by DoE Method, Metall. Ital., 2016, 6, p 141–144Google Scholar
- 37.M. Drouzy, S. Jacob, and M. Richard, Interpretation of Tensile Results by Means of Quality Index and Probable Yield Strength, AFS Int. Cast Met. J., 1980, 5(2), p 43–50Google Scholar
- 42.E. Sjolander, Heat Treatment of Al-Si-Cu-Mg Casting Alloys, Ph.D. Dissertation, Department of Mechanical Engineering School of Engineering, Jönköping University, 2011.Google Scholar
- 50.D. Askeland, P. Fulay, and W. Wright, The Science and Engineering of Materials, Cengage Learning, Boston, 2011Google Scholar