稀土Er对Al-Mg合金组织和性能的影响研究

Effect of rare earth Er on microstructure and properties of Al-Mg alloy

在Al-Mg合金的基础上,通过调整稀土元素Er的掺杂含量,制备了不同稀土Er掺杂量(0,0.3%,0.6%和0.9%)(质量分数)的Al-Mg合金。通过XRD、SEM、电子万能试验机和浸泡腐蚀试验研究了Al-Mg合金的晶体结构、微观形貌、力学性能和腐蚀性能。结果表明,所有Al-Mg合金的结晶性能都较好,未掺杂稀土Er的合金中主要有α-Al、Mg_(2)Si和Si相。掺杂稀土Er后,出现了Al_(3)Er的衍射峰,且随着稀土Er掺杂量的增加,衍射峰的强度逐渐升高。未掺杂稀土Er的Al-Mg合金的晶粒尺寸整体在190~210μm之间,掺入稀土Er后基体的晶粒尺寸明显变小,第二相的含量也变多。随着稀土Er掺杂量的增加,Al-Mg合金的抗压强度和延伸率均呈现出先升高后降低的趋势。当稀土Er的掺杂量为0.6%(质量分数)时,合金的抗拉强度和延伸都达到了最大值,分别为185.68 MPa和1.79%。Al-Mg合金的硬度则随着稀土Er掺杂量的增加持续上升,当稀土Er的掺杂量为0.9%(质量分数)时,合金的硬度达到了最大值67.9 HBW。未掺杂稀土Er的Al-Mg合金的相对腐蚀率为0.709%,掺杂稀土Er后合金的腐蚀率明显降低,当稀土Er的掺杂量为0.6%(质量分数)时,合金的相对腐蚀率最低为0.593%。综合分析可知,稀土Er的掺杂量为0.6%(质量分数)时,Al-Mg合金的性能最优。

On the basis of Al-Mg alloy,Al-Mg alloys with different rare earth Er doping contents(0,0.3 wt%,0.6 wt%and 0.9 wt%)are prepared by adjusting the doping content of rare earth Er.The crystal structure,micro morphology,mechanical properties and corrosion properties of Al-Mg alloys are studied by XRD,SEM,electronic universal testing machine and immersion corrosion test.The results show that all Al-Mg alloys have good crystallinity.The alloys without rare earth Er doping are mainlyα-Al,Mg_(2)Si and Si phases.After doping rare earth Er,the diffraction peak of Al_(3)Er appears,and the intensity of the diffraction peak increases gradually with the increase of rare earth Er doping.The grain size of Al-Mg alloy without rare earth Er doping is 190-210μm as a whole,the grain size of the matrix decreases obviously and the content of the second phase increases after the addition of rare earth Er.With the increase of rare earth Er doping,the compressive strength and elongation of Al-Mg alloy increase first and then decrease.When the doping amount of rare earth Er is 0.6 wt%,the tensile strength and elongation of the alloy reach the maximum,which are 185.68 MPa and 1.79%,respectively.The hardness of Al-Mg alloy continues to increase with the increase of rare earth Er doping.When the doping amount of rare earth Er is 0.9 wt%,the hardness of the alloy reaches the maximum value of 67.9 HBW.The relative corrosion rate of Al-Mg alloy without rare earth Er doping is 0.709%.And the corrosion rate of the alloy is significantly reduced after doping rare earth Er.When the doping amount of rare earth Er is 0.6 wt%,the lowest relative corrosion rate of the alloy is 0.593%.The comprehensive analysis shows that the performance of Al-Mg alloy is the best when the doping amount of rare earth Er is 0.6 wt%.