微观结构与力学性能的影响
(西北工业大学 材料科学与工程学院, 西安 710072)
摘 要: 采用透射电镜和扭转试验研究了外加静电场对LY12CZ合金摩擦焊接头焊合区显微结构和力学性能的影响。 结果表明, 静电场提高了摩擦焊接头焊合区的合金元素固溶程度, 使s′相析出数量增多, 并以小尺寸弥散分布； 同时, 电场的激活作用降低了焊合区晶粒内的位错密度, 减少了位错缠结程度, 增加了位错的可动性。 因而, 合适的静电场可以加强摩擦焊接过程中晶界运动在协调焊合区金属塑性变形方面的作用, 提高焊接接头的塑性。
关键字: 电塑性效应； 摩擦焊接； LY12CZ合金； 显微结构； 力学性能
mechanical properties of
friction welding joint of LY12CZ alloy
（College of Materials Science and Engineering,
Northwestern Polytechnical University, Xi'an 710072, China）
Abstract:By means of TEM and the torsion test, the microstructure and the mechanical properties of the friction welding joint of LY12CZ alloy in the presence of the electrical field were studied. The results show that the external electric field increases the solubility of the alloy elements in the weld zone of the friction welding joint, promotes the formation of the precipitation phases with a small size and a dispersion distribution. Meanwhile, the dislocation density in the grain and the entwining degree of dislocation decrease in the presence of the electric field. Hence the external electric field harmonizes the plastic deformation in the weld zone, and improves the plasticity of the friction welding joint.
Key words: electroplastic effect； friction welding； LY12CZ alloy； microstructure； mechanical properties
