Supplementary materials

FIG. S1. (a) Schematic setup for ultrasonic interferometry measurements on acoustic velocities and elasticity of NbxTiZrHf HEAs; (b) Representative compressional and shear wave echoes of Nb0.2TiZrHf HEAs.
FIG. S2. SEM micrographs of the well-polished surface of the NbxTiZrHf (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) specimens together with their corresponding EDS mapping.
FIG. S3. SEM images and grain size distributions of the NbxTiZrHf (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) HEAs.
FIG. S4. Vickers hardness of refractory NbxTiZrHf HEAs at various loading forces.
FIG. S5. (a) A schematic diagram of cracking modeling for indentation fracture toughness; (b) Representative SEM micrographs of the fracture surface from our Vickers hardness indentation measurement of the Nb0.2TiZrHf specimen.
FIG. S6. Selected area TEM imaging of the propagation crack of Nb0.2TiZrHf specimen.
FIG. S7. High-resolution TEM images corresponding to the bcc phase and hcp phase in Nb0.2TiZrHf HEAs.

图 S1. (a) NbxTiZrHf 高熵合金的超声干涉法测量声速和弹性的示意图；(b) Nb0.2TiZrHf 高熵合金的代表性压缩波和剪切波回波。图 S2. NbxTiZrHf (x = 0, 0.2, 0.4, 0.6, 0.8, 和 1.0) 样品经精抛光表面的扫描电子显微镜图像及其相应的能谱图像映射。图 S3. NbxTiZrHf (x = 0, 0.2, 0.4, 0.6, 0.8, 和 1.0) 高熵合金的扫描电子显微镜图像和晶粒尺寸分布。图 S4. 不同加载力下耐高温的 NbxTiZrHf 高熵合金的维氏硬度。图 S5. (a) 压痕断裂韧性裂纹建模的示意图；(b) 来自我们用维氏硬度压痕法对 Nb0.2TiZrHf 样本进行测量的断裂表面的代表性扫描电子显微镜图像。图 S6. Nb0.2TiZrHf 样本裂纹扩展的选区透射电子显微镜成像。图 S7. 对应于 Nb0.2TiZrHf 高熵合金中的体心立方相和六方密堆积相的高分辨率透射电子显微镜图像。