Microstructural processing of steel at ambient surface temperature
Microstructural processing of steel at ambient surface temperature
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DOI：
10.1016/j.msea.2021.141233
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发表时间：
2021-04
期刊：
影响因子：
6.4
通讯作者：
J. Kidd;Zahabul Islam;D. Waryoba;A. Haque
中科院分区：
文献类型：
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作者：
J. Kidd;Zahabul Islam;D. Waryoba;A. Haque
我们提供的证据表明，金属材料的微观结构处理，可以在较低的温度下通过直流电流，同时冷却试样。由于焦耳热被移除，由于动量转移到缺陷的电子风力成为晶界和缺陷迁移的主要刺激物。我们在标称50 μm厚的增材制造316不锈钢试样上演示了这种技术，在约200 A/mm 2电流密度下电偏置，同时主动冷却以保持环境表面温度。微观结构分析包括电子背散射衍射、晶界取向差图和晶粒尺寸分析。实验结果表明，晶粒生长和晶粒细化是可能的，这取决于控制的温度和处理时间。结果还表明，晶粒生长和晶粒细化的取向差角分布的显着变化，几乎所有的低角度晶界被转换为高角度晶界。这些结果对于进一步发展电子风力作为金属和合金低温后处理的驱动力是令人鼓舞的。
We provide evidence that microstructural processing of metallic materials can be achieved at lower temperatures by passing dc current and simultaneously cooling the specimens. As the Joule heat is removed, the electron wind force due to transfer of momentum to defects become the predominant stimulant for grain boundary and defect migration. We demonstrate this technique on nominally 50 μm thick additive manufactured 316 stainless steel specimens, electrically biased at around 200 A/mm2current density while actively cooled to maintain ambient surface temperature. The microstructural analysis involved electron backscattered diffraction, grain boundary misorientation plots, and grain size analysis. Experimental results indicate that both grain growth and grain refinement are possible, depending upon the controlled temperature and processing time. The results also showed significant changes in misorientation angle distributions for both grain growth and grain refinement with almost all low angle grain boundaries being converted to high angle grain boundaries. These results are encouraging for further development of the electron wind force as a driver for low temperature post processing of metals and alloys.