Development of a Matlab-Based Characterization Suite – Application to Metal Foam and Composite Ceramic Waste Form Microstructures

Microstructural properties influence material performance, particularly in advanced energy applications such as nuclear waste storage, fuel cells, and batteries. A Matlab-based characterization suite has been developed using algorithms which calculate 3-D properties such as particle size distributions, connectivity, interfacial areas, TPB lengths, and tortuosity for all phases in a given material. Thorough microstructure characterization will lead to insights on how each property affects the performance of a material in application. In this work, this characterization suite has been applied to metal foams and ceramic waste form materials. Metal foams have been studied extensively for use in heat transfer applications. These materials offer high thermal conductivity and area available for convection at low density compared to bulk metals. Ceramic waste forms have been examined as a means of nuclear waste immobilization that offers improved performance compared to traditional borosilicate glass based technologies. These materials typically contain multiple crystalline phases such as hollandite, pyrochlore, and perovskite, and as a result, are characterized by complex microstructures. Two composite ceramic waste form systems containing Ga-doped Ba hollandite, Ba1.33Ga2.66Ti5.34O16, and pyrochlore, Nd2Ti2O7, were imaged using differential X-ray absorption contrast tomography (DXACT). DXACT is a synchrotron-based 3-D imaging technique capable of resolving spatial distributions of specific elements in a sample. Using the 3-D elemental maps obtained from DXACT, the microstructural properties of one ceramic waste form system was calculated and its performance determined using the characterization suite