Malopheyev Sergey S, Zuiko Ivan S, Mironov Sergey Yu, Kaibyshev Rustam O
Laboratory of Mechanical Properties of Nanoscale Materials and Superalloys, Belgorod National Research University, Pobeda 85, Belgorod 308015, Russia.
Materials (Basel). 2023 Apr 5;16(7):2898. doi: 10.3390/ma16072898.
The purpose of this work was the examination of microstructural evolution during the fabrication of an Al/AlO composite by friction stir processing (FSP). In order to obtain new insight into this process, a longitudinal section of the produced composite was studied, and advanced characterization techniques (including electron backscatter diffraction and microhardness mapping) were applied. It was found that the reinforcing particles rapidly rearranged into the "onion-ring" structure, which was very stable against the subsequent dispersion. Specifically, the remnants of the comparatively coarse-scale particle agglomerations have survived even after 12 FSP passes. Therefore, it was concluded that three or four FSP passes, which are often applied in practice, are not sufficient to provide a homogeneous dispersion of the reinforcing particles. It was also revealed that the gradual distribution of the nanoscale AlO particles throughout the aluminum matrix promoted a subtle reduction in both the portion of high-angle boundaries and the average grain size. These observations were attributed to the particle pinning of grain-boundary migration and dislocation slip.
这项工作的目的是研究搅拌摩擦加工（FSP）制备Al/AlO复合材料过程中的微观结构演变。为了深入了解这一过程，对制备的复合材料的纵向截面进行了研究，并应用了先进的表征技术（包括电子背散射衍射和显微硬度映射）。研究发现，增强颗粒迅速重排为“洋葱环”结构，该结构对随后的分散非常稳定。具体而言，即使经过12次FSP道次，相对粗尺度颗粒团聚体的残余物仍留存下来。因此，得出的结论是，实际中常用的三到四次FSP道次不足以使增强颗粒均匀分散。研究还表明，纳米级AlO颗粒在整个铝基体中的逐渐分布促使高角度晶界比例和平均晶粒尺寸略有减小。这些观察结果归因于颗粒对晶界迁移和位错滑移的钉扎作用。
