Effect of isothermal extrusion parameters on mechanical properties of Al–Si eutectic alloy

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2011-08, Vol.528 (21), p.6504-6509
• Main Authors: Deng, Lei, Wang, Xinyun, Xia, Juchen, Li, Jianjun
• Format: Article
• Language: English
• Subjects: Aluminum base alloys; Al–Si eutectic alloy; Applied sciences; Cracks; Elasticity. Plasticity; Elongation; Eutectic alloys; Exact sciences and technology; Extrusion; Isothermal extrusion; Materials science; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microstructure; Reduction
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2011.05.009

► Mechanical properties of Al–Si eutectic alloy extruded with different parameters. ► Positive correlation between tensile strength and temperature higher than 623 K. ► Negative correlation between elongation and temperature lower than 673 K. ► Positive correlation between elongation and temperature higher than 673 K. ► Reduction in elongation when section reduction ratio is 85%. In this paper, mechanical properties of a deformed Al–Si eutectic alloy processed by isothermal extrusion at temperature from 573 K to 773 K with reduction ratio from 25% to 85% were investigated at ambient temperature. The results showed that a banded structure composed of matrix region and accumulation region of second phase particles was formed and a few cracks were generated in particles and evolved to voids among particles. The tensile strength of test specimens ranged from 250 MPa to 400 MPa and was directly related with temperature from 623 K to 773 K. The elongation of test specimens ranged from 2.8% to 13.1%, and had a peak value at 673 K under each section reduction ratio. A reduction in elongation occurred at section reduction ratio larger than 75% because of particle bands splitting aluminum matrix severely. The effect of temperature on mechanical properties was more significant than that of section reduction ratio. Excellent balance between strength and ductility can be obtained by extrusion at temperature 623–723 K and section reduction ratio 40–70%.