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采用粉末冶金技术制备了不同Si含量(0,0.1,0.3wt%Si)的Mo-Si合金板材,并在25,300,800和1200℃下进行了静拉伸试验,研究了试验温度对Mo-Si合金板材力学性能、断裂方式及微观组织的影响。结果表明:随试验温度升高,纯钼及Mo-Si合金板材强度明显下降,但延伸率以300℃为分界点呈现出先升后降的趋势。室温下Mo-Si合金的断裂方式为穿晶解理断裂,在300及800℃时主要为韧窝延性断裂,而1200℃时为沿晶断裂。对Mo-Si合金强化机制的分析表明,室温下的强化主要来源于弥散强化和固溶强化,而在高温时,固溶作用明显减弱,颗粒弥散和粗化晶粒为主要的强化手段。
Mo-Si alloy sheets with different Si contents (0, 0.1, 0.3wt% Si) were prepared by powder metallurgy technology and static tensile tests were carried out at 25,300,800 and 1200 ℃. The effects of test temperature on the mechanical properties of Mo-Si alloy sheet Mechanical properties, fracture mode and the impact of microstructure. The results show that with the increase of test temperature, the strength of pure molybdenum and Mo-Si alloy sheet decreases obviously. However, the elongation of the pure molybdenum and Mo-Si alloy sheet increases first and then decreases with 300 ℃ as the cut-off point. The fracture mode of Mo-Si alloy at room temperature is transgranular cleavage fracture, ductile fracture mainly at 300 and 800 ℃, and intergranular fracture at 1200 ℃. The analysis of the strengthening mechanism of Mo-Si alloy shows that the strengthening at room temperature mainly comes from the dispersion strengthening and solution strengthening. At high temperature, the solid solution dissolves weakly and the particles are dispersed and coarsened.