Hot Deformation Behavior and Microstructure Evolution of a DC Cast Hypereutectic Al-Si Alloy
Hot Deformation Behavior and Microstructure Evolution of a DC Cast Hypereutectic Al-Si Alloy
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DOI：
10.4028/www.scientific.net/amm.151.332
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发表时间：
2012-01
期刊：
影响因子：
--
通讯作者：
K. He;F. Yu;D. Zhao;L. Zuo
中科院分区：
文献类型：
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作者：
K. He;F. Yu;D. Zhao;L. Zuo
研究了一种直流铸造过共晶Al-Si合金在400-500 °C温度范围和0.001 ~ 1 s-1应变速率范围内的热变形行为和组织演变。结果表明，该合金的铸态组织由多边形初晶Si颗粒和α-Al枝晶晕组成，Al-Si共晶和金属间化合物偏析在枝晶间。合金的流变应力是温度和应变速率的强函数，峰值应力随变形温度的降低和应变速率的增加而增大。试验中的真应力-真应变曲线均表现为动态软化。随着变形温度的升高和应变速率的降低，初生Si颗粒的断裂频率降低。动态流变软化主要是动态再结晶的结果。
The hot deformation behavior and microstructure evolution of a DC cast hypereutectic Al-Si alloy was studied in the temperature range of 400-500 °C and strain rate range of 0.001-1 s-1. The results show that the as-cast microstructure of the alloy consists of polygonal primary Si particles and α-aluminum dendritic halos with Al-Si eutectics and intermetallic compounds segregated into the interdendritic regions. The flow stress of the alloy is a strong function of temperature and strain rate, and the peak stress is increased with the decrease of deformation temperature and the increase of strain rate. All the true stress-true stain curves in the experiments exhibit dynamic softening. The fracture frequency of primary Si particle is decreased with the increase of deformation temperature and the decrease of strain rate. The dynamic flow softening is mainly as a result of dynamic recrystallization.