Abstract Fe89.5Ni8Zr2.5 alloy was synthesized by mechanical alloying followed by pressureless sintering at various temperatures up to 900 °C. Microstructural evolution as a function of processing temperature was characterized using focused ion beam microscopy, transmission electron microscopy and X-ray diffraction techniques. The dependence of hardness on the microstructure was utilized to study the mechanical changes. The experimental results showed that microstructural stability can be enhanced by segregation of solutes to grain boundaries at low temperatures and by precipitation of second phases at elevated temperatures. Eventually, at higher processing temperatures the stability was lost due to the coarsening of the precipitated second phases leaving behind ultra-fined grained microstructure. Despite the coarsening of the grain size with increasing processing temperatures, the in-situ formed second phases were found to induce an Orowan strengthening effect leading to approximately 5.5 GPa hardness after 1 h sintering at 900 °C.

中文翻译：

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了解通过机械合金化和无压烧结生产的纳米结构 Fe89.5Ni8Zr2.5 合金的显微组织演变和硬度

摘要 Fe89.5Ni8Zr2.5合金是通过机械合金化，然后在高达900°C的各种温度下无压烧结合成的。使用聚焦离子束显微镜、透射电子显微镜和 X 射线衍射技术表征作为加工温度函数的微结构演变。利用硬度对微观结构的依赖性来研究机械变化。实验结果表明，在低温下溶质向晶界偏析和在高温下第二相的沉淀可以增强微观结构的稳定性。最终，在更高的加工温度下，由于析出的第二相粗化，留下超细晶粒微观结构，稳定性丧失。