Microstructure and Properties of Rare Earth Ce Modified Cast Al-12.35Si Alloy

Author of the article:XIE Peipei 1 , SHI Pan 1 , LI Fangfeng 2 , FENG Zengjian 2 , LI Yanjun 2 , CUI Yanshou 2 , LIU Zhiwei 1

Author's Workplace：1. State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi 'an Jiaotong University, Xi ’ an 710049, China. 2. Binzhou Bohai Piston Co., Ltd., Binzhou 256600, China

Key Words： Ce; near eutectic Al-Si alloy; modification; microstructure; mechanical properties

Abstract：Al-12.35Si alloy was modified by adding Al-Ce rare earth master alloy. The effect of Ce content (0~ 0.8%) on
microstructure and mechanical properties of as-cast Al-12.35Si alloy was studied. The results show that adding appropriate
amount of Ce can reduce the size of eutectic silicon, refine the second phase, reduce the secondary dendrite arm spacing of
α-Al, and improve the mechanical properties of the alloy. However, when the addition of Ce is more than 0.2%, the
over-metamorphism will occur, which leads to the coarsening of the alloy microstructure and reduces the mechanical
properties of the alloy. When Ce content is 0.2% , the modification effect of Al-12.35Si alloy is ideal and the best
mechanical properties are obtained. Compared with the unmodified Al-12.35Si alloy, the tensile strength of the modified
alloy is increased from 168 MPa to 223 MPa, and the elongation is increased from 0.44% to 0.72%.