Effect of Y2O3 on microstructure and mechanical properties of hypereutectic Al-20%Si alloy
(1.Key Laboratory of Automobile Materials of Ministry of Education,Department of Materials Science and Engineering, Jilin University, Changchun 130025, China
2.吉林省长春市吉林大学材料科学与工程学院教育部汽车材料重点实验室)
2.吉林省长春市吉林大学材料科学与工程学院教育部汽车材料重点实验室)
Abstract: The effect of Y2O3 on the microstructure and mechanical properties of the hypereutectic Al-20%Si(mass fraction) alloy was investigated. The results show that, with the addition of Y2O3 into the Al-P-Ti-TiC modifier, the average size of primary silicon in the Al-20%Si alloy modified by Al-P-Ti-TiC-Y2O3 modifier (approximately 15mm or less) is significantly reduced, and the morphology of eutectic silicon changes from coarse acicular and plate like to refined fibrous. The Brinell hardness (HB189) and tensile strength (301 MPa) of Al-20%Si alloy modified by the Al-P-Ti-TiC-Y2O3 increase by 11.6% and 10.7%, respectively, for the alloys after heat treatment.
Key words: primary silicon; mechanical properties; hypereutectic Al-Si alloy; modification; eutectic silicon; heat treatment