The research objectives of this award are 1) to create a novel graded glass/alumina/glass (G/A/G) sandwich structure with improved contact, sliding and flexural damage resistance compared to its monolith alumina or glass counterpart for biomedical and engineering applications; and 2) to discover critical interrelationships between structure (micro and macro) and properties (fatigue contact, sliding, and flexural resistance) of functionally graded materials (FGMs) using a model G/A/G system. Contact, sliding, and flexure are the most common fatigue modes encountered in numerous biomechanical and engineering applications. G/A/G FGMs will be designed and synthesized, and their fatigue behavior will be investigated to establish the structure?{property relationships. Deliverables include the development of a family of new FGMs and new routes for their manufacture, better understanding of structure¡Vproperty relationships of FGMs, documentation of research results, graduate and undergraduate students¡¦ education, and research experiences for underrepresented minority high school students.
If successful, this research will lead to the development of next-generation structural ceramics with improved damage resistance for artificial joints, dental prostheses, aerospace, military, microelectronics, and other engineering applications. The proposed research will extend the current knowledge of fatigue behavior of FGMs and provide guidelines for designing FGMs across an array of applications. The testing method, loading a ball onto flat brittle layer(s) supported by a compliant substrate, is a simple yet powerful technique for elucidating contact, sliding, and flexural damage resistance of ceramics. The results will be disseminated to the biomedical, materials, and engineering literature to allow the creation of new venues for studying the fracture behavior of synthetic materials and biological tissues, as well as new materials and devices for the scientific and healthcare communities. Graduate, undergraduate science students and high school students will benefit through classroom instruction and involvement in the research.