ISSN: 1003-6326
CN: 43-1239/TG
CODEN: TNMCEW

Vol. 29    No. 8    August 2019

Effects of La-Ce addition on microstructure and mechanical properties of Al-18Si-4Cu-0.5Mg alloy
Gao-yong LIN1,2, Kun LI1,2, Di FENG3, Yong-ping FENG4, Wei-yuan SONG1,2, Meng-qiong XIAO1,2
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China;
3. School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212000, China;
4. Fujian Xiangxin Shares Co., Ltd., Fuzhou 350000, China
)
Abstract: The microstructural evolution and mechanical properties of Al-18Si-4Cu-0.5Mg alloy modified by the addition of La-Ce rare earth elements through OM, SEM, EPMA and tensile tests were investigated. The results of OM and SEM analyses indicated that primary Si particles were significantly refined from coarse block-like and irregular polygonal shapes into fine flaky shapes, while eutectic Si particles were modified from coarse and needle-like into fine and rod- or coral-like shapes with increase of La-Ce addition. The alloy exhibited the minimum primary Si particle size and the best mechanical properties with the addition of 0.3 wt.% La-Ce. The average particle size decreased from 61 to 28 μm, the ultimate tensile strength increased from 222 to 242 MPa and the elongation increased from 3.2% to 6.3%. In addition, modification mechanisms and fracture modes were explored by the means of SEM and EPMA.
Key words: Al-18Si-4Cu-0.5Mg alloy; primary Si; eutectic Si; La-Ce addition; mechanical properties
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
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