多孔CoCrNi中熵合金的力学性能和吸能特性分析

Mechanical Properties and Energy Absorption Characteristics of Porous CoCrNi Medium-Entropy Alloy

采用粉末烧结-溶解法成功制备了孔隙率为63%~78%,孔径1.3~2.2 mm的多孔CoCrNi中熵合金,借助SEM和XRD对试样的孔形貌和物相组成进行分析,并对试样进行轴向准静态压缩实验研究。结果表明:多孔CoCrNi中熵合金的弹性模量和屈服平台应力均随孔隙率、孔径的增大而减小;相对孔隙率而言,孔径对力学性能的影响程度较低;不同孔隙率的多孔CoCrNi中熵合金其致密应变下单位体积的能量吸收值为34.81~14.25 MJ/m^(3),约为泡沫铝的3.8倍,且5种孔隙率合金的理想吸能效率(I)都接近0.8,说明该多孔CoCrNi中熵合金有潜力成为一种理想的吸能材料。

The porous CoCrNi medium-entropy alloys with porosity of 63%-78%and pore size of 1.3-2.2 mm were prepared by powder sintering and dissolution method.The pore morphology and phase constitute of the samples were analyzed by SEM and XRD,and the axial quasi-static compression experiments were conducted on the samples.The results show that the elastic modulus and yield platform stress of porous CoCrNi alloy decrease with the increase in porosity and pore size.Compared with porosity,the effect of pore size on mechanical properties is low.The energy absorption value per unit volume in porous CoCrNi medium-entropy alloys with different porosities ranges from 34.81 MJ/m^(3) to 14.25 MJ/m^(3)under dense strain,which is about 3.8 times larger than that of aluminum foam,and the ideal energy absorption efficiency(I)of the alloys with five kinds of porosities is close to 0.8,indicating that the porous CoCrNi medium-entropy alloy has the potential to become an ideal energy absorption material.