Microstructures and properties of Al-45%Si alloy prepared by liquid-solid separation process and spray deposition  

液固分离和喷射沉积制备Al-45%Si合金的组织及性能(英文)

作　　者：李艳霞[1,2] 刘俊友[1] 王文韶[1] 刘国权[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]北华航天工业学院材料系,廊坊065000

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第4期970-976,共7页中国有色金属学报（英文版）

摘　　要：The microstructures and properties of A1-45%Si alloy prepared by liquid-solid separation （LSS） process and spray deposition （SD） were studied. The results show that the size, shape and distribution of the primary Si phase have different influence on the properties of alloys. Comparing with the Si particles with irregular shape, fine size and continuous distribution in SD alloy, the primary Si phase in LSS alloy is sphere-like, coarse and surrounded by the continuous AI matrix. The microstructure features of LSS alloy are beneficial to the higher thermal conductivity and lower thermal expansion coefficient at room temperature. The fine Si particle in SD alloy is advantageous to improving the mechanical properties. The increasing rates of thermal expansion coefficient with temperature are influenced by the distribution of the Si particles, where a lower rate is obtained in SD alloy with continuous Si particles. The agreement of thermal expansion coefficient with the model in LSS alloy differs from that in the SD alloy because of the different microstructure characteristics.对液固分离法(LSS)和喷射沉积法(SD)制备的Al-45%Si合金组织和性能进行研究。结果表明,两种方法制备的合金中初生Si相具有不同的尺寸、形态和分布,从而对合金性能产生不同的影响。采用喷射沉积法制备的合金中硅相形状不规则,尺寸细小并在空间连续分布。液固分离法制备的合金中硅相形态呈近球形,尺寸较大并被连续的铝基体包覆。与喷射沉积合金相比,液固分离制备合金具有更高的热导率和更低的低温热膨胀系数,但由于硅颗粒尺寸较大,力学性能低于喷射沉积合金。硅相的分布形式对热膨胀系数的增加速率影响显著,其中喷射沉积法制备的合金中硅相连续分布有利于获得低的增加速率。由于组织特征的不同,液固分离制备合金的热膨胀系数预测模型与喷射沉积制备的合金有区别。

关 键 词：aluminum-silicon alloy Si particle liquid-solid separation spray deposition thermal conductivity thermal expansioncoefficient 

分 类 号：TG146.21[一般工业技术—材料科学与工程]