快速凝固法制备过饱和CuCr合金时效析出动力学  

Kinetics of Aging Precipitation of CuCr Alloy by Rapidly Solidification

作　　者：冯晶[1] 陈敬超[1] 于杰[1] 肖冰[2] 李强[3] 周晓龙[1] 

机构地区：[1]昆明理工大学稀贵及有色先进材料教育部重点实验室,云南昆明650093 [2]西安交通大学,陕西西安710049 [3]河南理工大学,河南焦作454000

出　　处：《稀有金属材料与工程》2009年第2期281-285,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50361003);云南省自然科学基金重点项目(2006E003Z);昆明理工大学创新基金资助

摘　　要：在不同时效温度下研究雾化法制备过饱和CuCr合金的时效析出动力学。通过能谱测定不同时刻的析出相体积分数,用Avrami方程分析不同温度的时效动力学,发现扩散是相变的主要控制因素,而固溶原子、杂质、空位、位错、晶界和点阵畸变等都会对析出动力学产生影响。研究发现,低温时效的初期会形成无序的溶质富集区,析出相与基体之间保持共格关系。电子衍射和能谱分析表明,随着时效时间的增加,Cr元素不断在基体中富集,会形成明显的G.P区,最后形成单质Cr相。而在高温时效时,由于原子迁移的激活能容易满足,Cr元素析出动力较大且富集很快,完成析出过程的时间很短,会在材料内部迅速生成单质Cr相,很难观察到G.P区。Supersaturated CuCr solid solution was prepared by pulverization. After that, the aging dynamics were analyzed at different temperatures. The results showed that the G.P zone was presented at relatively low temperature. We could observe a coherent interface between precipitated phase and matrix. The results that were obtained both from transmission electron microscope （TEM） and Electron Energy Disperse Spectroscopy （EDS） revealed that as aging time increased, the amount of Cr metal phase also increased due to solute enrichment process. On the other hand, the activation energy for atomic diffusion was reduced at high temperature. As a result, the metal phases of Cr were formed very fast. The fractional volume of the precipitated phase was measured by EDS and then applied Avrami equation to analyze the dynamical effect of aging. Finally we concluded that the phase transition in CuCr alloy was determined by aging dynamics and diffusion was the most important effect of aging process, other factors such as solute species, impurities, vacancies, dislocations, grain boundaries and lattice distortions may be affected this process, too.

关 键 词：铜合金 相变动力学 扩散 CuCr固溶体 电导率 

分 类 号：TG146.4[一般工业技术—材料科学与工程]