An in-situ plasma spark sintering (SPS) apparatus, coupled with laboratory X-ray microscopy, was utilized to three-dimensionally investigate the dynamic evolution process of 7055 aluminum alloy during SPS process. The influences of sintering temperatures and particle morphology on the sintering kinetics were discussed in detail. It was observed that elevating the sintering temperatures enhanced both the rate of densification and the final compactness of the alloy. Furthermore, three-dimensional quantitative analysis of pore evolution indicated that greater discrepancies in powder size between neighboring particles facilitated pore elimination during sintering by increasing available interstitial spaces. Mechanistic analysis rationalized these observations by attributing the enhanced sintering kinetics to the greater particle size disparity, which resulted in higher necking curvature and accelerated densification. The present study therefore provides a comprehensive three-dimensional in-situ quantitative analysis on the dynamic SPS process, and is expected to advance the current comprehension of sintering mechanisms at the micron scale.

利用原位等离子火花烧结 (SPS) 装置与实验室 X 射线显微镜相结合，对 7055 铝合金在 SPS 过程中的动态演化过程进行了三维研究。详细讨论了烧结温度和颗粒形貌对烧结动力学的影响。据观察，提高烧结温度可以提高合金的致密化速率和最终致密性。此外，孔隙演化的三维定量分析表明，相邻颗粒之间的粉末尺寸差异较大，通过增加可用的间隙空间，有利于烧结过程中孔隙的消除。机械分析通过将增强的烧结动力学归因于更大的颗粒尺寸差异来合理化这些观察结果，这导致更高的颈缩曲率和加速致密化。因此，本研究对动态 SPS 过程提供了全面的三维原位定量分析，有望推进目前对微米尺度烧结机制的理解。