Microstructure and properties of high silicon aluminum alloy with 2％ Fe prepared by rheo-casting
The morphology changes of both Fe-containing intermetallic compounds and the primary Si phase of Al-20Si-2Fe- 2Cu-0.4Mg-1.0Ni-0.5Mn (mass fraction,％) alloy produced by semi-solid rheo-diecasting were studied.The semi-solid slurry of high silicon aluminum alloy was prepared by direct ultrasonic vibration (DUV) which was imposed on the alloy near the liquidus temperature for about 2 min.Then,standard test samples of 6.4 mm in diameter were formed by semi-solid rheo-diecasting.The results show that the DUV treatment suppresses the formation of needle-like β-Al5(Fe,Mn)Si phase,and the Fe-containing intermetallic compounds exist in the form of fine Al4(Fe,Mn)Si2 particles.Additionally,the primary Si grows up as fine and round particles with uniform distribution in α(Al) matrix of this alloy under DUV treatment.The tensile strengths of the samples at the room temperature and 573 K are 230 MPa and 145 MPa,respectively.The coefficient of thermal expansion (CTE) between 25 ℃ and 300 ℃ is 16.052 8×10-6 ℃-1,and the wear rate is 1.55％.The hardness of this alloy with 2％ Fe reaches HB146.3.It is discovered that modified morphology and uniform distribution of the Fe-containing intermetallic compounds and the primary Si phase are the main reasons for reducing the CTE and increasing the wear resistance of this alloy.
high silicon aluminum alloy ultrasonic vibration rheo-casting microstructure mechanical properties
ZHONG Gu WU Shu-sen AN Ping MAO You-wu LI Shi-zhao
State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China
国际会议
北京
英文
1603-1607
2010-09-16（万方平台首次上网日期，不代表论文的发表时间）