磁场处理2024铝合金的塑性和微观机制  

Plasticity and microstructure of 2024 aluminum alloy treated by magnetic physics fields

作　　者：李桂荣[1] 李超群 韩松 王宏明[1] 程江峰[1] LI Guirong;LI Chaoqun;HAN Song;WANG Hongming;CHENG Jiangfeng(School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013,China)

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《江苏大学学报（自然科学版）》2019年第3期344-349,共6页Journal of Jiangsu University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51371091;51174099);江苏大学第15批大学生科研立项资金资助项目(15A379);江苏大学工业中心大学生创新实践基金资助项目(ZXJG2018102)

摘　　要：在不同磁感应强度B和脉冲数N下,用强脉冲磁场处理2024铝合金试样,进行力学性能和电子顺磁共振波谱测试.结果显示:合金延伸率和未成对电子数之间呈现对应关系;当B=1 T,N=30个时,合金延伸率最大,此时波谱曲线上吸收强度最大,对应未成对电子数最多.分析认为:在优化参数条件下,因磁场能量满足电子激发条件,促使未成对电子数增高,材料顺磁性增强;未成对电子来自位错和合金相等位错钉扎中心,含有这些未成对电子的结构单元构成自由基对,在磁场作用下,自由基对从单线态向三重态发生转化,对应位错和钉扎中心结合键能由强变弱,有助于位错退钉扎和塑性提高.The 2024 aluminum alloy was treated by high pulsed magnetic field with different magnetic induction intensities( B ) and pulse numbers( N ), and the mechanical properties and electron paramagnetic resonance (EPR) spectra were determined.The results show that the variation tendency of maximum value on EPR curve is identical to elongation. Under the conditions with B of 1 T and N of 30, the maximum elongation is obtained with the largest absorption intensity in EPR spectrum, which implies a maximum number of unpaired electrons. For the optimized parameters, the magnetic field energy can satisfy the electron excitation conditions, which accelerates the increasing of unpaired electron concentration and the enhancement of alloy paramagnetism. The unpaired electrons come from the dislocation and the dislocation pinning centers of alloyed precipitates, and the structure units tend to form free radical pairs. In the presence of magnetic field, the free radicals transfer from singlet to triplet state, and the strong bonding between dislocations and pinning center correspondingly becomes weak, which facilitates the depinning of dislocations and the improvement of plasticity.

关 键 词：铝合金 电子顺磁共振 脉冲强磁场 位错 塑性 

分 类 号：TG113[金属学及工艺—物理冶金]