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通过放电等离子烧结(SPS)制备T2(Mo5SiB2)相合金,并采用SEM、XRD及压痕、压缩和三点弯曲等实验对合金的微观组织和室温力学性能进行表征。结果表明:SPS法以独特的等离子活化烧结方式制备出纯度高、致密且晶粒细小的T2相合金。该合金在室温压缩下几乎没有塑性变形,抗压强度为2907MPa;维氏硬度为17.86GPa,压痕法测得的断裂韧性为3.23MPa·m1/2,与三点弯曲法测得的3.34MPa·m1/2接近,沿{001}面发生解理断裂。共价键交替排列,是T2相室温脆性、高强度、高硬度的根本原因。
The T2 (Mo5SiB2) phase alloy was prepared by spark plasma sintering (SPS). The microstructure and room temperature mechanical properties of the alloy were characterized by SEM, XRD, indentation, compression and three-point bending. The results show that the SPS method can produce T2 phase alloy with high purity, compactness and fine grain by the unique plasma activation sintering method. The alloy has almost no plastic deformation under room temperature compression with a compressive strength of 2907 MPa, a Vickers hardness of 17.86 GPa, a fracture toughness of 3.23 MPa · m1 / 2 as measured by an indentation method, and 3.34 MPa · M1 / 2 close to cleavage fracture along the {001} plane. The covalent bonds are alternately arranged, which is the fundamental reason of room temperature brittleness, high strength and high hardness of T2 phase.