Measurement of Internal Residual Strain Gradients in Metal Matrix Composites Using Synchrotron Radiation

Abstract

Low density titanium based metal matrices combined with high strength and stiffness ceramic fibers are under widespread investigation for possible use in high temperature aerospace applications [1]. Inherent in the processing of these composite materials are the residual stresses resulting from the thermal expansion coefficient mismatch between the fiber and matrix. A tensile hoop and a compressive radial stress result upon cooling from the consolidation temperature because the fiber has a smaller expansion coefficient [2]. The thermal stresses can be very large and may exceed the matrix yield or even fracture stress [3].