Micromechanism Based Modeling of Structural Life in Metal Matrix Composites
Abstract
This report details the most recent accomplishments that have lead towards the fulfillment of the grant objectives. These achievements include: (1) life prediction of continuous fiber metal matrix composites; (2) the influence of heat treatment on the mechanical properties and damage development in a SiC/Ti-15-3 MMC; (3) the experimental characterization of oxidation on fracture surfaces and crack growth behavior; (4) modeling the effects of oxidation on the crack growth resistance of metals; and (5) the modeling of oxidation fronts in metals. In summary, the development of a low-cycle life prediction model that has the capability to account for the effect of surface oxidation on life of Titanium matrix MMC's is complete. The research performed herein concluded that the life of the composite appears to be controlled by interface debonding and subsequent radial cracking. The work performed under this grant also included a program to experimentally characterize the morphology of TiO2, one of the primary stoichiometric oxides formed during oxidation of titanium, in order to develop more accurate oxide layer growth models. It has been shown that specimen geometry plays a significant role in the rate of oxide growth. The last phase of this research effort was to develop and numerically implement a mathematical model of oxidation for metals with the capability of modeling complex oxidation fronts, such as they arise in MMC's. The oxidation of metals has been modeled by modifying the Fickian diffusion problem in order to simulate the chemical reaction (phase change) in the metal. The current model is capable of solving 1D and 2D oxidation problems in metallic domains with complex geometry.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 23, 1997
- Accession Number
- ADA345560
Entities
People
- David H. Allen
- Dimitris C Lagoudas
Organizations
- Texas A&M University