中文摘要：

研究了硼元素对AlCoCrFeNiBx（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。

英文摘要：

The influences of B element on the microstructure and properties of AlCoCrFeNiBx（x=0, 0.1, 0.25, 0.5, 0.75, 1.0, mol ratio） high entropy alloys were investigated. The AlC oC rF eN i high entropy alloy exhibits equiaxed grain morphology, and then turns to dendritic structures when B content x=0.1. The spinodal decomposition microstructure can be clearly observed in equiaxed grains. When x0.1, both of the dendrite and the spinodal decomposition microstructure gradually disappear, but much borides form instead. The transformation is attributed to the high negative mixing enthalpy of Cr-B and Co-B. The microstructures of AlC oC rF eN iB x high entropy alloys change from B2＋bcc structures to B2＋bcc＋fcc structures, and finally formed B2＋bcc＋fcc and borides mixing structures with the increased B elements. The hardness HV declines from 4860 to 4607 MPa, then rises to 6157 MPa with the addition of B element. The lowest hardness value is obtained when x=0.1. The compressive fracture strength shows a distinct decrease with B addition. The maximum compression strength is 2227 MPa when x=0.25. But when x reaches 0.75, the samples fracture during the elastic deformation due to the formation of hard and brittle borides. The coercive forces and the specific saturation magnetizations of the alloys decrease as the contents of B element increase. The decreasing coercive forces show a better soft magnetic behavior.