Abstract Scope |
Grain growth is a critical behavior in powder processing to control properties of polycrystal ceramics. Abnormal grain growth, in which a small fraction of grains grow at a faster rate than their neighbors, results in heterogeneous microstructures with unpredictable performance. The mechanism enabling such growth behavior is unknown, making it difficult to predict and avoid. This work focuses on identifying the microstructural features associated with abnormal grain growth to identify sintering strategies to mitigate such behavior. Specifically, the role of large pores in the initiation of abnormal grain growth in Ca-doped alumina will be demonstrated using 3D x-ray diffraction contrast tomography. Additionally, the effect of the thermal history on the grain boundary energy distribution and, thus, subsequent grain growth will be shown in strontium titanate. The implications of these studies on how sintering conditions can be used to limit or promote abnormal grain growth will be discussed. |