Vol.29 Suppl.1 王静松等：S-15%Pb合金电脉冲孕育处理效果时间相关性研究 ·153 研究中，合金熔体经电脉冲处理，其中较小的原子 (2)电脉冲处理时间不同，处理效果是不同的， 团簇开始长大，而原有的大原子团簇同时也会发生 随着处理时间的递增呈现出一定的规律性.表现为： 崩解.脉冲时间在30到120s之间内，聚集长大的 初生相形核过冷度的“小幅减小一大幅减小一小幅 原子团簇多于崩解的原子团簇，它们部分达到了临 减小一大幅减小”，对应富Sn颗粒晶的“少量出 界尺寸，在合金凝固时可以成为晶核继续长大，当 现一大量出现一少量出现一大量出现”， 脉冲时间接近120s的某一范围内时，熔体中原有 参考文献 大量小的原子团簇同时长大到某一临界尺寸的条 件，新形成的大原子团簇远超过崩解的原子团簇，这 [1]Misra A K.Misra technique applied to solidification of cast iron. 样在合金熔体凝固时提供了大量晶核，促使凝固组 Metallurgical Transactions,1986,17A:358 2]Nakada M,Flemings MC.Modification of solidification struc. 织富Sn枝晶的等轴化，进而使初生相过冷度大幅 tures by pulse electric discharging.ISIJ International,1990,30 减小.当脉冲时间再延长后，大的原子集团大量同 (1上27 时崩解，导致了满足形核条件原子集团的数量急剧 [3】王建中，电脉冲孕育处理技术研究及液态金属团簇结构假说 减少，所以初生相过冷度再次增加，此时凝固组织 [学位论文1.北京：北京科技大学，1998 中富Sn枝晶也会再次出现，同理反复就呈现出凝 [4]Shi X D,Wang J S,Xue Q G,et al.Effect of electric pulse 固组织中初生相颗粒状晶的数量的周期性变化， treatment on solidification structure of an Al-15%Si alloy.Rare etals,2005,24(3:289 4结论 [5】刘国勋.金属学原理.北京：治金工业出版社，1980 [6]边秀房，王伟民，李辉，等。金属熔体结构。上海：上海交通 (1)Sn-15%Pb合金熔体经电脉冲处理后，合金 大学出版社，2003 [7]Wang J S,Xue Q G,Chang G W,et al.Effects of electric pulse 凝固组织和凝固过程均发生明显变化.经电脉冲处 on microstructure of Al-Si alloy in liquid and solid states.Jour- 理120s后，凝固组织中初生相富Sn枝晶转变为颗 nal of University of Science and Technology Beijing,2004,11 粒状，冷却曲线反应出的初生相形核过冷度大幅减 (2):123 小. Experimental study on time correlation of treating time and electric pulse modi- fying effects on Sn-15%Pb alloy WANG Jingsong,YU Wentao,TANG Peixin,LIU Bo,CAO Lijun),XUE Qingguo 1)Metallurgical and Ecological Engineering School,University of Sciences and Technology Beijing,Beijing 100083,China 2)Post-doctoral Station of USTB,Post-doctoral Work Station of Laigang Group,Shandong 271104,China 3)Qian'an ShouGang Co.Ltd.,Hebei 064404,China ABSTRACT Molten Sn-15%Pb alloy,which was used as the test material,was treated with electric pulse for different treating time under the condition of 90C overheating.The modifying effects on solidification process and structures were investigated by thermal analysis and solidification structure observation.The results showed that the solidification structures of Sn-15%Pb alloy were changed significantly after electric pulse modifying. The morphology of primary crystal enriched Sn changed from dendrite to cellular.Corresponding with the changing of solidification structures,the cooling curves were changed significantly.The lowest temperature of primary crystallizing increased in a rather large range.With the increasing of electric pulse process time,the amount of cellular primary crystal changed periodically,that is little,large,little,large.At the same time,the lowest temperature of primary crystallizing also changed periodically with the extension of electric pulse treating time. KEY WORDS Sn-Pb alloy;electric pulse modifying;solidification structure;treating time;cooling curveVol.29 Suppl.1 王静松等：Sn-15％Pb 合金电脉冲孕育处理效果时间相关性研究 • 153 • 研究中，合金熔体经电脉冲处理，其中较小的原子 团簇开始长大，而原有的大原子团簇同时也会发生 崩解．脉冲时间在 30 到 120 s 之间内，聚集长大的 原子团簇多于崩解的原子团簇，它们部分达到了临 界尺寸，在合金凝固时可以成为晶核继续长大．当 脉冲时间接近 120 s 的某一范围内时，熔体中原有 大量小的原子团簇同时长大到某一临界尺寸的条 件，新形成的大原子团簇远超过崩解的原子团簇．这 样在合金熔体凝固时提供了大量晶核，促使凝固组 织富 Sn 枝晶的等轴化，进而使初生相过冷度大幅 减小．当脉冲时间再延长后，大的原子集团大量同 时崩解，导致了满足形核条件原子集团的数量急剧 减少，所以初生相过冷度再次增加，此时凝固组织 中富 Sn 枝晶也会再次出现，同理反复就呈现出凝 固组织中初生相颗粒状晶的数量的周期性变化． 4 结论 (1)Sn-15%Pb 合金熔体经电脉冲处理后，合金 凝固组织和凝固过程均发生明显变化．经电脉冲处 理 120 s 后，凝固组织中初生相富 Sn 枝晶转变为颗 粒状，冷却曲线反应出的初生相形核过冷度大幅减 小． (2)电脉冲处理时间不同，处理效果是不同的， 随着处理时间的递增呈现出一定的规律性．表现为： 初生相形核过冷度的“小幅减小－大幅减小－小幅 减小－大幅减小”，对应富 Sn 颗粒晶的“少量出 现－大量出现－少量出现－大量出现”． 参 考 文 献 [1] Misra A K. Misra technique applied to solidification of cast iron. Metallurgical Transactions, 1986, 17A: 358 [2] Nakada M, Flemings M C. Modification of solidification struc￾tures by pulse electric discharging. ISIJ International, 1990, 30 (1): 27 [3] 王建中．电脉冲孕育处理技术研究及液态金属团簇结构假说 [学位论文]. 北京：北京科技大学，1998. [4] Shi X D, Wang J S，Xue Q G，et al. Effect of electric pulse treatment on solidification structure of an Al-15%Si alloy. Rare Metals, 2005, 24 (3): 289 [5] 刘国勋．金属学原理．北京：冶金工业出版社，1980 [6] 边秀房，王伟民，李辉，等．金属熔体结构．上海：上海交通 大学出版社，2003 [7] Wang J S, Xue Q G, Chang G W，et al. Effects of electric pulse on microstructure of Al-Si alloy in liquid and solid states. Jour￾nal of University of Science and Technology Beijing, 2004, 11 (2): 123 Experimental study on time correlation of treating time and electric pulse modi￾fying effects on Sn-15％Pb alloy WANG Jingsong1, 2), YU Wentao3), TANG Peixin1), LIU Bo1), CAO Lijun1) , XUE Qingguo1) 1) Metallurgical and Ecological Engineering School, University of Sciences and Technology Beijing, Beijing 100083, China 2) Post-doctoral Station of USTB, Post-doctoral Work Station of Laigang Group, Shandong 271104, China 3) Qian’an ShouGang Co. Ltd., Hebei 064404, China ABSTRACT Molten Sn-15%Pb alloy, which was used as the test material, was treated with electric pulse for different treating time under the condition of 90℃ overheating. The modifying effects on solidification process and structures were investigated by thermal analysis and solidification structure observation. The results showed that the solidification structures of Sn-15%Pb alloy were changed significantly after electric pulse modifying. The morphology of primary crystal enriched Sn changed from dendrite to cellular. Corresponding with the changing of solidification structures, the cooling curves were changed significantly. The lowest temperature of primary crystallizing increased in a rather large range. With the increasing of electric pulse process time, the amount of cellular primary crystal changed periodically, that is little, large, little, large. At the same time, the lowest temperature of primary crystallizing also changed periodically with the extension of electric pulse treating time. KEY WORDS Sn-Pb alloy; electric pulse modifying; solidification structure; treating time; cooling curve