Seminar
Title: |
Interface Failure at the Nanoscale |
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Speaker: |
Dr. Shuman Xia |
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Affiliation: |
California Instititute of Technology, Pasadena, CA |
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When: |
Monday, April 5, 2010 at 11:00:00 AM |
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Where: |
MRDC Building, Room 4211 |
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Host: |
Dr. David McDowell | |
Abstract Metal matrix composites have replaced conventional homogeneous materials in many engineering applications due to their superior mechanical and thermal properties, such as light weight, high specific stiffness and strength, high thermal conductivity, low coefficient of thermal expansion, and excellent creep and wear resistance. The reinforcement/matrix interfaces in such composites play a crucial role as the medium of load transfer in determining the overall material performance. Therefore, it is important to characterize the mechanical properties of the interfaces for tailoring the microstructure of the materials. In this talk, a combined experimental and computational study of nanoscale interface failure in an in-situ Al/Si composite will be presented. Nanoindentation is employed to introduce interface failure at the nanoscale by indenting individual reinforcement particles. The failure mechanisms and processes under indentation are simulated by finite element analysis with a mesh-size-dependent cohesive zone model. In the computational model, a scaling law of the cohesive zone strength is developed to bridge the atomic-scale and finite element cohesive laws. Within the framework of the cohesive zone model, the nanoscale mechanical properties of the interface are extracted by tracing the canonical response of the nanoindentation experiments to the simulation results. |
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Biography Bio not available at this time. |
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