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The microstructures and Vickers hardness at room temperature of arc-melting processed intermetallics ofMo_5Si_3-MoSi_2 hypoeutectic alloy and hypereutectic alloy annealed at 1200℃ for different time were investigated. Lamellarstructure consisted of Mo_5Si_3 (D8m) phase and MoSi_2 (Cll_b) phase was observed in all the alloys. For Mo_5Si_3-MoSi_2hypoeutectic alloy, the lamellar structure was found only for annealing and developed well with fine spacing on the orderof hundred nanometers after annaling at 1200℃ for 48h. But when the annealing time was up to 96h, the well-developedlamellar structure was destroyed. For Mo_5Si_3-MoSi_2 hypereutectic alloy, the lamellar structure was found both before andafte annealing. However the volume fraction and spacing of the lamellar structure did not change significantly before andafter annealing. The effects of the formation, development and destruction of lamellar structure on Vickers hardness of al-loys were also investigated. When Mo_5Si_3-MoSi_2 hypoeutectic all
The microstructures and Vickers hardness at room temperature of arc-melting processed intermetallics of Mo_5Si_3-MoSi_2 hypoeutectic alloy and hypereutectic alloy annealed at 1200 ℃ for different time were investigated. Lamellarstructure consisted of Mo_5Si_3 (D8m) phase and MoSi_2 (C11_b) phase was observed in all the alloys. For Mo_5Si_3-MoSi_2hypoeutectic alloy, the lamellar structure was found only for annealing and developed well with fine spacing on the order of hundred nanometers after annaling at 1200 ℃ for 48h. But when the annealing time was up to 96h, the well-developedlamellar For the volume fraction and spacing of the lamellar structure did not change significantly before and after annealing. The effects of the formation, development and destruction of lamellar structure on Vickers hardness of al-loys were also investigated. When Mo_5Si_3-MoS i_2 hypoeutectic all