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分别通过还原气氛常压烧结法(TFS)和放电等离子烧结法(SPS)制备Mo5Si B2(T2)相合金,并采用XRD,SEM和TEM等方法对合金的微观结构进行表征.结果表明:快的升温速率是合成T2相的动力学条件,相比传统烧结方式,SPS法以独特的等离子活化烧结方式提供快的加热速率,能够在较短的时间内升温到所需温度1500℃,避免Mo,Si和B混合粉末在中温区间(600~1200℃)通过固-固反应生成Mo3Si,Mo5Si3和Mo B等二元相,而通过固-液反应原位合成T2相.合金平均晶粒尺寸为1.44 mm,晶界清晰、洁净、无过渡区且在晶体内没有观察到位错等缺陷.
The microstructure of Mo5Si B2 (T2) alloy was prepared by atmospheric pressure sintering (TFS) and spark plasma sintering (SPS) in reducing atmosphere respectively. The microstructure of the alloy was characterized by XRD, SEM and TEM. The heating rate is the kinetic condition for synthesizing T2 phase. Compared with the traditional sintering method, the SPS method provides a fast heating rate by a unique plasma activated sintering method, and can be heated to a desired temperature of 1500 ° C. in a relatively short period of time to avoid Mo, The binary phase of Mo3Si, Mo5Si3 and MoB was formed by the solid-solid reaction between Si and B powders at medium temperature range (600 ~ 1200 ℃), while the T2 phase was synthesized by in-situ solid-liquid reaction.The average grain size of alloy was 1.44 mm, the grain boundary is clear, clean, no transition zone and no defects such as dislocation are observed in the crystal.