中文摘要：

针对Sn-Al体系不易混熔的难点,通过粉末压片与真空电弧熔炼相结合的方法,成功制备了添加稀土的Sn-Cu-Al无铅焊料,并研究了添加微量单一稀土Ce、La和混合稀土RE对其显微组织和可焊性（熔化特性、润湿性）的影响。实验结果表明,不同稀土的添加均能使Sn-0.7Cu-0.075Al合金的组织均匀细化,单一稀土Ce、La的添加对基体合金的细化效果优于混合稀土RE的。单一稀土Ce、La的添加使基体合金的熔点从229.82℃分别降低到227.06℃和227.38℃,而混合稀土RE的添加对基体合金熔点影响不大,不同微量稀土的添加均略微降低了基体合金的熔程。不同微量稀土的添加均改善了基体合金的润湿性能。其中,单一稀土Ce的改善作用最明显,使基体合金铺展率从68.61%提升至73.88%,润湿角从34.6°下降到26.6°。

英文摘要：

In order to solve the immiscible problem of Sn-Al system,a series of Sn-Cu-Al lead-free solders added with rare earth were prepared by powder pressing and vacuum arc melting,and the effects of the single rare earth Ce,La and the mixed rare earths on the microstructure and solderability properties of solders were studied. The results showed that the addition of different rare earths could refine and uniform the microstructure of the solders. Moreover,the single rare earths Ce or La performed better than the mixed rare earth. The single rare earths Ce or La reduced the melting point of the matrix alloy from 229. 82 ℃ to 227. 06 ℃ and 227. 38 ℃ respectively,while the mixed rare earths affected little. However,the melting range was slightly reduced benefited from the rare earthaddition. All kinds of rare earth improved the weldability of the matrix alloy with the single rare earth Ce increased the most,changing the spreading rate and the wetting angle of the matrix alloy from68. 61% to 73. 88%,34. 6 degrees to 26. 6 degrees respectively.