Quantitative Analysis of Heterogeneous Microstructure and Diversified Strengthening Mechanisms in Spark Plasma Sintered Molybdenum Disilicide

• DOI: 10.1007/s11661-015-2785-8
• Publication Date: 2015-02-10T14:29:08Z
• Authors: Qiaodan Hu; Peng Luo; Youwei Yan; Jianguo Li
• Keywords: 0103 physical sciences; 01 natural sciences

Molybdenum disilicide (MoSi2) was in situ synthesized by spark plasma sintering into fully dense bulk material. Electron backscatter diffraction revealed that over the range from the center to periphery of the cylindrical sample, the microstructure is heterogeneously constituted by gradually refined MoSi2 grains and increasing amounts of Mo5Si3 impurity phase. The diversified strengthening mechanisms are primarily attributed to the Peierls–Nabarro stress in MoSi2 matrix, the Hall–Petch strengthening effect, and thermal mismatch stress between Mo5Si3 and MoSi2.