Sandia National Laboratories has a major R&D program synthesizing and processing ceramic materials. By integrating a wide range of synthesis techniques, preparation strategies, and characterization capabilities, we develop new materials and processes for fabricating electronic and structural ceramics, thin films, composites, catalysts, and membranes.
powder for high-performance varistors.
Ceramic Synthesis: Our expertise and capabilities in synthesizing ceramics are based on chemical solution techniques. Chemical solution or sol-gel approaches have been developed to fabricate powders, films, and porous bodies. Materials of interest range from silica to complex, multicomponent electronic ceramics. The complexity inherent in fabricating materials with structured nanoporosity or complex chemistries requires a fundamental understanding of these chemical solution approaches. Fabrication of unique precursors for complex oxides is being done with novel metal alkoxide chemistry to produce powders and thin-film materials with carefully controlled properties. Our ability to synthesize materials with complex structures, chemistries, or both, is at the heart of numerous research and development efforts at Sandia.
Robocasting is a new slurry-based
approach for direct fabrication
of complex ceramics.
Ceramic Processing: Sandia's fabrication of ceramic components and devices is based on a strong ceramic-processing capability. We recently have demonstrated the ability to characterize and model the powder-compaction process in detail, and to address and control density gradients in powder compacts that cause shape distortion and differential shrinkage. Proprietary 3D, finite-element code packing and compaction models, and process-control tools are now available to improve the production of ceramic components. Sandia has capabilities in the areas of hydrostatic and triaxial compaction testing to characterize materials properties, and x-ray radiography, ultrasound, and computed tomography for density characterization. In addition, expertise in slurry processing has enabled the development of direct-fabrication processes. Furthermore, we are developing phenomenological sintering models to enhance both ceramic component design and manufacturing capability.
Calculated residual stresses due to thermal
expansion anisotropy in an alumina
body after cooling from 1,500°C.
Ceramic and Glass Joining: Sandia has developed a comprehensive set of techniques for engineering ceramic-metal and glass-metal joints. When joining is ignored until after the design is fixed, it is often a significant constraint rather than an enabling part of the process. We combine materials science, mechanical design, and process engineering to ensure that selected component designs are manufacturable, and joining technology is effectively integrated into the product-design process. Proprietary finite-element modeling (FEM) codes and supercomputers can efficiently test component designs without having to build prototypes. The capability for developing novel ceramics, glasses, and joining products and processes ensures compatibility with candidate alloys, thus enabling the development of products and devices with improved performance.
Mechanical Characterization, Reliability, and Failure Analysis: Sandia has a long history in designing, testing, and analyzing failures of glass and ceramic materials for a variety of applications, including connectors, glass and ceramic-to-metal seals, rolamite switches, batteries, sprytrons, krytrons, and actuators. We have a unique ability in one location to integrate proprietary finite-element models, nondestructive evaluation, analytical materials characterization, scanning and transmisssion electron microscopy, mechanical testing and failure analysis, and fractography. Sandia has used this expertise to address numerous reliability/failure problems for a wide range of customers. Recently, we used Object Oriented Finite Element Analysis (OOF) in combination with NASA's CARES/LIFE program to develop a more quantitative method for assessing the reliability of ceramic components.
Contacts: Paul Clem, (505) 845-7544, firstname.lastname@example.org