Morphologies of strontium-modified A357 alloy and its mechanisms
(School of Materials Science and Engineering,
Harbin Institute of Technology, Harbin 150001, China)
Harbin Institute of Technology, Harbin 150001, China)
Abstract: The microstructure evolution for A357 alloy modified by original Al-10Sr alloy was systematically investigated. The results show that the eutectic silicon phase gets finer and more homogeneous with the increase of Sr content and the modifying temperature. Modification at the performing temperature of 740℃ and with Sr contents of 0.03%-0.05% (mass fraction) turns the microstructure into the finest fibers. And the mechanism of evolution was also investigated based on the TEM observation.
Key words: A357 alloy; original alloy; modification; eutectic silicon