过冷Cu-Pb偏晶合金的凝固热力学分析  

Solidification Thermodynamic Analysis of Undercooled Cu 34.15wt% Pb Monotectic Alloy Melt

作　　者：孙万里[1] 张忠明[1] 徐春杰[1] 郭学锋[1] 

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048

出　　处：《材料热处理学报》2005年第6期53-56,共4页Transactions of Materials and Heat Treatment

基　　金：陕西省教育厅专项科研计划项目(03JK132);陕西省自然科学研究计划项目(2003E1)

摘　　要：采用熔融玻璃净化和循环过热相结合的方法实验研究了Cu-34.15%Pb偏晶合金在0～204K的宽过冷度区间的冷却曲线.实验结果表明,Cu-34.15%Pb偏晶合金在较小过冷时只有一次再辉,较大过冷时有两次再辉,偏晶反应中液相L2恒为初生相.根据经典形核理论和冷却曲线讨论了偏晶合金的两相竞争形核规律,并推断出Cu-Pb合金偏晶反应中液液相变焓△HL的取值范围为5×108～1.8375×109J·m-3.研究发现,△HL的大小对于偏晶反应中的α相和L2相的两相竞争形核起着至关重要的作用,需要精确地测定.The cooling curves of Cu-34.15wt%Pb monotectic alloy melt undercooled by the method of molten glass denucleating combined with cyclical superheating were studied. Only one recalescence stage occurred in melts with low undercoolings, while two recalescence stages were observed in the melts with high undercoolings. The competing nucleation of L2 phase and α(Cu) phase in Cu-Pb monotectic reaction was discussed by using the classic nucleation theory and the experimental cooling curves. The results show that the liquid phase L2 serves as the primary phase in Cu-Pb monotectic reaction, and the enthalpy of phase change ΔHL, in the monotectic reaction of Cu-34.15%Pb alloy is in the range of 5 × 108 J&middotm-3 - 1.8375 × 109 J&middotm-3. In addition, the accurate determination of ΔHL is very important, which influences the competing nucleation of α(Cu) phase and L2 phase.

关 键 词：深过冷 CU-PB偏晶合金 经典形核理论 液液相变焓 

分 类 号：TG131[一般工业技术—材料科学与工程] TG111.4[金属学及工艺—合金]