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研究了硼元素对AlCoCrFeNiB_x(x=0,0.1,0.25,0.5,0.75,1.0,x为摩尔百分比)高熵合金微观组织和性能的影响。AlCoCrFeNi高熵合金呈等轴晶结构,晶内伴随着明显的成分偏析,在等轴晶内可以观察到典型的调幅分解结构。然而,当x=0时,合金却转变为树枝晶结构。随着硼元素的进一步添加,树枝晶以及调幅分解结构都开始逐渐消失,并在晶体中形成大量的硼化物;晶体结构也由B2+bcc结构转变为B2+bcc+fcc的混合结构,最终转变为B2+bcc+fcc+硼化物的混合结构;合金硬度HV呈先降后升的趋势,由4860 MPa降低至4607 MPa,最后又升高至6157 MPa,其中x=0.1时合金硬度最低;抗压缩断裂强度呈明显的下降趋势,在硼元素含量达到0.75时,合金试样甚至在弹性变形阶段即发生了脆性断裂;本系列合金均呈现软磁性,其矫顽力和饱和磁化强度均随着硼元素含量的增加而下降,而下降到矫顽力显示出硼元素对合金的软磁性有提高作用。
The effect of boron on the microstructure and properties of high-entropy alloys with AlCoCrFeNiB_x (x = 0,0.1,0.25,0.5,0.75,1.0, x is mole percent) was studied. The AlCoCrFeNi high-entropy alloy has an equiaxed crystal structure with obvious component segregation in the crystal, and a typical amplitude-modulated decomposition structure can be observed in the equiaxed crystal. However, when x = 0, the alloy transforms into a dendritic structure. With the further addition of boron, the dendrites and the amplitude modulation decomposition structure began to disappear, and formed a large number of borides in the crystal; the crystal structure was also changed from the B2 + bcc structure to the B2 + bcc + fcc mixed structure, and finally transformed Which is the mixed structure of B2 + bcc + fcc + borides. The hardness of alloy HV decreases first and then increases from 4860 MPa to 4607 MPa and finally to 6157 MPa, where the hardness of alloy is the lowest when x = 0.1. The fracture strength shows a declining trend. When the content of boron reaches 0.75, the brittle fracture occurs even in the elastic deformation stage of the alloy specimen. All the alloys in this series exhibit soft magnetic properties. The coercive force and saturation magnetization all change with boron Element content increases and decreases, and down to the coercivity shows that the boron element on the soft magnetic properties of the alloy.