2Al2铝合金预置裂纹脉冲电流处理初探  

Preliminary study on pulsed current treatment of preset cracks in 2Al2 aluminum alloy

作　　者：王立伟[1,2] 毛亚宁 王守勇 梁志敏 汪殿龙[1,2] Wang Liwei;Mao Yaning;Wang Shouyong;Liang Zhimin;Wang Dianlong(Hebei University of Science and Technology,Shijiazhuang 050018,China;Hebei Key Laboratory of Near Net Forming Technology of Materials,Shijiazhuang 050018,China)

机构地区：[1]河北科技大学,石家庄050018 [2]河北省材料近净成形技术重点实验室,石家庄050018

出　　处：《焊接》2022年第4期32-36,47,共6页Welding & Joining

基　　金：国家自然科学基金资助项目(51875168);河北省自然科学基金资助项目(E2019208089,E2020208089,E2020208083)。

摘　　要：文中进行了脉冲电流对2Al2铝合金预制裂纹的修复试验,观察了脉冲电流处理前后试样的微观组织变化,测试了脉冲电流对试件硬度和抗拉强度的影响。试验结果表明,峰值电流为295 A,410 A和656 A,作用时间分别为1.5 s,1.5 s和2.25 s,电压为4 V的脉冲电流均可使裂纹呈愈合趋势。峰值电流为410 A的脉冲电流裂纹愈合效果最好,裂纹尖端周围区域晶粒得到细化。脉冲电流处理前、后试件硬度平均值分别趋近于130 HV,125 HV,脉冲电流在裂纹尖端区域的焦耳热效应使该区域发生回复与再结晶,内应力消除,硬度降低。脉冲电流处理前、后试件的平均抗拉强度分别为273 MPa,281.7 MPa,裂纹区域的高密度脉冲电流加速位错移动,使抗拉强度提高了3.19%。文中使用参数调控简便的UN1-1型对焊机作为脉冲电流处理电源,采用了锤击预制裂纹方法,得到的裂纹与实际更为接近,并通过试验验证了2Al2铝合金裂纹脉冲电流修复的可行性。Repairing tests of preset cracks in 2Al2 aluminum alloy were carried out by pulsed current in this paper.Microstructure of specimens before and after pulsed current treatment were observed,and effects of pulsed current on hardness and tensile strength of specimens were tested.The results showed that it tended to heal preset cracks when peak currents were 295 A,410 A and 656 A,electrifying times were 1.5 s,1.5 s and 2.25 s respectively,and voltage was 4 V.When pulsed current was 410 A peak current,it had the best cracks healing effect,and grains around the crack tip were refined.Average micro-hardness of specimens before and after pulsed current treatment approached 130 HV and 125 HV,respectively.Joule heating effect of pulsed current at the crack tip zone promoted aluminum alloy to recover and recrystallize,internal stress was eliminated,and micro-hardness decreased.Average tensile strength of specimens before and after pulsed current treatment were 273 MPa and 281.7 MPa,respectively.High-density pulsed current at crack zone accelerated movement of dislocations and increased tensile strength by 3.19%.UN1-1 butt welding machine with simple parameter regulation was used as pulsed current treatment power source in this paper.Hammering method was used to preset cracks.The obtained cracks were closer to the actual cracks.Feasibility of pulsed current repairing cracks of 2Al2 aluminum alloy was verified.

关 键 词：2Al2铝合金 脉冲电流处理 裂纹修复 力学性能 

分 类 号：TG456.9[金属学及工艺—焊接]