电脉冲处理对金属材料组织、力学性能影响的研究进展

Effect of Electropulsing Treatment on the Microstructure and Mechanical Properties of Metallic Materials:a Review

多能量场辅助材料加工成形是先进制造技术发展的重要方向,其中电脉冲处理(EPT)是一种利用脉冲电流实现材料微观组织调控与力学性能改善的新型处理技术,在辅助金属材料制备和加工等领域有着广阔的应用前景。电脉冲处理具有能量利用率高、作用时间短等优点,在提高材料塑性、促进再结晶和相变等方面具有传统热处理无法比拟的优势。近年来,金属材料组织、力学性能对电脉冲处理的响应行为受到国内外学者的广泛关注。当脉冲电流加载于金属材料时,电场作用下的漂移电子与材料内部组织会发生相互作用,产生焦耳热效应、电迁移效应等电致塑性效应。因此,电脉冲处理能够增强原子扩散、促进位错运动,提高材料塑性变形能力。同时,脉冲电流能够显著促进晶粒细化、固态相变与织构弱化,从而使材料获得优异的综合力学性能。此外,电脉冲处理还可以实现材料内部孔洞和微裂纹的修复,有效抑制裂纹的扩展,从而提高材料的断裂韧性和延长材料的疲劳寿命。本文基于现有研究现状,从晶粒细化、固态相变、裂纹修复等方面,总结分析了电脉冲处理对金属材料微观组织和力学性能的影响规律与作用机制,同时,简要介绍了电脉冲处理改善焊接接头成形特征和性能的相关研究,最后对电脉冲处理技术后续研究进行了展望。

Multi-energy field assisted processing is an important direction for the development of advanced manufacturing technology.Electropulsing treatment(EPT)is an innovative technology,which has been used to improve the microstructure and mechanical properties of metallic materials by applying electric pulse current.The EPT has broad promising applications in the manufacturing industry.Due to the advantages of energy saving and high efficiency that can quickly heat up materials,EPT has preponderance over conventional heat treatment in terms of improving material plasticity,promoting recrystallization and phase transformation.The response of microstructure and mechanical properties of metal materials to EPT has attracted wide attention.The coupling effects,including joule heating effect,electromigration effect and other electroplastic effects,could enhance the atomic diffusion and dislocation migration to improve the forming ability.In addition,pulse current can significantly promote grain refinement,solid-state phase transition,and texture weakening,so as to obtain excellent comprehensive mechanical properties.In addition,EPT can repair internal porosities and cracks of the material to effectively inhibit the crack propagation and improve the fracture behavior.Based on the existing research,the effect of EPT on the microstructure and mechanical properties of materials has been summarized and the mechanism is preliminarily analyzed from the aspects of grain refinement,solid-state phase transition,and crack repair.Moreover,the related researches on the formation characteristics and performance of welded joints after EPT are also included in the paper.Finally,the follow-up research on EPT is discussed.