电场对2E12铝合金时效微观组织和动力学的影响  

Effect of electric field on microstructure and kinetics in aging of 2E12 aluminum alloy

作　　者：洪天然[1] 易丹青[1,2] 周明哲[1] 王宏伟[1] 丁珣[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]中南大学教育部有色金属材料科学与工程重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2013年第2期493-500,共8页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51071177)

摘　　要：通过示差扫描量热法(DSC)、透射电镜(TEM)和电阻率测量方法研究电场处理对2E12铝合金时效微观组织和时效动力学的影响。研究结果表明:预变形190℃时效5 h处理的2E12铝合金样品时效过程中施加电场能使促进后续时效进程,使DSC曲线中S相析出放热峰的峰值温度降低15℃,最大相变速率增加75%,相变完成所需时间减少20%。施加电场能使铝空位形成能降低26%,增加铝空位的浓度,从而导致预变形2E12铝合金样品时效过程中在位错线上形核的S′相粒子体积分数和尺寸更大。这些粒子阻碍了基体内位错密度由于回复而降低的过程,使得样品在时效处理后保持较高密度的位错。位错与空位的共同影响使得后续时效过程中S相析出的速率加快。The effect of electric field on the microstructure and aging kinetics of 2E12 aluminum alloy was investigated by differential scanning calorimetry （DSC）, transmission electron microscopy （TEM） and resistivity measurement. The results show that the continued aging of 190 ℃, 5 h aged pre-deformed 2E12 aluminum alloy is promoted by applied electric field. The S phase formation peak in DSC curve is reduced by 15 ℃, the maximum phase transition rate is increased by 75% and the time required for completion of phase transition is reduced by 20%. The formation energy of AI vacancies is reduced by 26% and the density of A1 vacancies is increased with the effect of electric field, which causes the volume fractions and sizes of S＇ phase particles to increase. The dislocation density in aged sample keeps a higher lever due to the retard, which is caused by the particles, of the reducing process of the dislocation density in matrix during recovery. With the influence of dislocations and vacancies, the formation of S phase during continued aging process is promoted.

关 键 词：2E12铝合金 电场 时效动力学 析出相 空位 位错 

分 类 号：TG146.21[一般工业技术—材料科学与工程]