MoAlB has been regarded as a promising high-temperature structural ceramic, but the strength and toughness are still insufficient in the practical application. In this work, MoAlB ceramic bulk with superior hardness, strength and toughness has been fabricated by adding 0.15 mol. % Si. The MoAlB-0.15Si bulk is composed of Si-doped MoAlB, Mo(Al, Si)₂ and ultrafine Al₂O₃. The Vickers hardness ranges from 14.2 to 12.5 GPa with the tested load increasing from 10 to 200 N. The Vickers indentation remains the intact tetragonum in spite of the appearance of corner cracks, indicating the excellent damage tolerance. The flexural strength, fracture toughness and compressive strength of MoAlB-0.15Si are 518.46 MPa, 7.01 MPa m^1/2 and 2.62 GPa, respectively, obviously superior to the present MoAlB polycrystalline bulk. Si doping, grain refinement, strengthening effect of ultrafine Al₂O₃ and phase transformation from Al₈Mo₃ to Mo(Al, Si)₂ jointly account for the improvement of comprehensive properties of MoAlB bulk.

MoAlB 被认为是一种很有前途的高温结构陶瓷，但在实际应用中其强度和韧性仍然不足。在这项工作中，通过添加 0.15 mol 制备了具有优异硬度、强度和韧性的 MoAlB 陶瓷体。%硅。MoAlB-0.15Si 块体由 Si 掺杂的 MoAlB、Mo(Al, Si) ₂和超细 Al ₂ O _{3 组成}。维氏硬度范围从 14.2 到 12.5 GPa，测试载荷从 10 增加到 200 N。尽管出现角裂纹，维氏压痕仍然保持完整的四方体，表明具有优异的损伤容限。MoAlB-0.15Si的抗弯强度、断裂韧性和抗压强度分别为518.46 MPa、7.01 MPa m ^1/2和 2.62 GPa，明显优于目前的 MoAlB 多晶块体。Si掺杂、晶粒细化、超细Al ₂ O _{3 的}强化作用以及Al ₈ Mo ₃到Mo(Al, Si) _{2 的}相变共同导致MoAlB块体综合性能的提高。