Fine-grained and multi-phase Mo-Si-B alloy contains many grain/phase interfaces, which allows for optimizing its performances by modifying its interfaces. Based on the structure design, this study introduces the SiC whisker in a multi-phase Mo-Si-B alloy. The Mo-12Si-8.5B-SiC alloy, which used a liquid–liquid doping method to mix the SiC whiskers in the mechanical alloyed powder, was also synthesised by hot pressing. The microstructure, strength and toughness were experimentally examined, and the solid-state reaction and thermodynamic calculations were analysed to evaluate the effect of the SiC whisker. Microstructural observations showed that the SiC addition could regulate the phase constitution by markedly increasing the intermetallic content and, moreover, decrease the α-Mo content in the Mo-Si-B alloy. This effect resulted in a change in the microstructure, which was transformed from a continuous α-Mo matrix of the SiC-free Mo-12Si-8.5B alloy to a fine-grained intermetallic matrix of the Mo-12Si-8.5B-SiC alloy. Some SiO₂ particles distributed at the grain and phase boundaries could be decreased by the SiC addition, which was mainly related to the grain/phase boundary purifying effect derived from the interfacial reactions of the whisker and matrix. The high strength of the intermetallic matrix with a small amount of silica in the Mo-Si-B-SiC alloy is beneficial for enhancing the strength and fracture toughness.

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finegrained intermetallic siosub2sub particles toughness solidstate reaction microstructure strength thermodynamic calculations grain and phase boundaries addition sic whisker fracture continuous mo matrix interfacial reactions multiphase mosib alloyed phase constitution liquidliquid doping method grainphase interfaces mo12si85b

Bin Li,Laiping Li,Guojun Zhang,Xiaohui Lin,Pingxiang Zhang,.Optimization of Multi-phase Mo-12Si-8.5B Alloy by SiC Whisker. 70 (11),2529–2536.

Bin Li, et al."Optimization of Multi-phase Mo-12Si-8.5B Alloy by SiC Whisker" 70

Bin Li,Laiping Li,Guojun Zhang,Xiaohui Lin,Pingxiang Zhang,"Optimization of Multi-phase Mo-12Si-8.5B Alloy by SiC Whisker"