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为研究热氢处理技术对Ti2AlNb基合金板材高温拉伸变形行为的影响,在实验温度为870、900、930和990℃,应变速率为2.5×10-2s-1条件下,对H含量为0%和0.2%(质量分数)的Ti-22Al-25Nb合金板材进行了高温拉伸实验,并对其微观组织进行了分析。结果表明:0.2%H可以降低合金板材的高温流动应力,提高延伸率。在930℃变形时,置氢合金的峰值应力比未置氢合金下降了约36%,延伸率比未置氢合金提高了约53%。氢致合金软化和增塑的主要机制是H促进了α2相的动态再结晶,促进了b/B2相的位错运动和动态回复,提高了b/B2相的含量。
In order to study the effect of hydrothermal treatment on tensile deformation behavior of Ti2AlNb-based alloy sheet at high temperature, with the experimental temperature of 870, 900, 930 and 990 ℃ and the strain rate of 2.5 × 10-2s-1, % And 0.2% (mass fraction) of Ti-22Al-25Nb alloy sheet was subjected to high temperature tensile test, and its microstructure was analyzed. The results show that 0.2% H can reduce the high temperature flow stress and increase the elongation of the alloy sheet. When deformed at 930 ℃, the peak stress of the hydrogen-absorbing alloy decreased by about 36% compared with that of the unhydrogen-free alloy, and the elongation rate was increased by 53% compared with that of the unhydrogen-free alloy. The main mechanism of hydrogen-induced softening and plasticizing is that H promotes the dynamic recrystallization of α2 phase, promotes the dislocation movement and dynamic recovery of b / B2 phase, and increases the b / B2 phase content.