电化学阴极充氢对AZ31镁合金力学性能的影响

Effect of Electrochemical Cathode Hydrogen Charging on Mechanical Properties of AZ31 Magnesium Alloy

AZ31镁合金的氢致开裂行为(HIC)会促使结构件突发性脆断,容易造成安全隐患。对AZ31镁合金进行电化学阴极充氢,采用慢应变速率试验(SSRT)、氢含量测量、扫描电子显微镜(SEM)、X射线衍射仪(XRD)观察等手段研究了其对AZ31镁合金的拉伸力学性能的影响。结果表明:合金试样的力学性能随充氢时间的延长而下降,并且充氢时间越长,氢含量越高。其次,随着充氢的进行,氢在镁合金基体的晶界上扩散,导致晶胞晶格常数增加,进而降低镁合金晶粒的平均结合能和原子间结合力,最终使得AZ31镁合金的氢脆敏感性(IHE)增大。

The hydrogen⁃induced cracking(HIC)behavior of AZ31 magnesium alloy can cause sudden brittle fracture of structural parts,which can easily cause safety hazards.In this work,electrochemical cathodic hydrogen charging was performed on AZ31 magnesium alloy,and its effect on the tensile mechanical properties of AZ31 magnesium alloy was studied using slow strain rate test(SSRT),hydrogen content measurement,scanning electron microscopy(SEM)and X⁃ray diffraction(XRD).Results showed that the mechanical properties of the alloy specimens decreased with the prolongation of hydrogen charging time,and the hydrogen content increased with the prolongation of hydrogen charging time.Meanwhile,as hydrogen charging proceeded,hydrogen diffused on the grain boundaries of the magnesium alloy substrate,and the lattice constant of the cell increased,which further decreased the average binding energy and the interatomic binding force of magnesium alloy grains and finally improved the hydrogen embrittlement sensitivity(IHE)of AZ31 magnesium alloy.