Changes in the microstructure of QE22 composites estimated by non-destructive methods

Using non-destructive methods changes in the microstructure of QE22 metal matrix composites (MMC) due to thermal cycling have been investigated. Thermal stresses induced in the composites due to a difference between thermal expansion coefficient of matrix and ceramic particles may create new dislocations during the cooling from elevated temperatures. The thermal stresses can achieve the yield stress in the matrix and micro-glide of new created dislocations as well as their annihilation can occur. Thermodynamic processes in the matrix influences these effects. (C) 2002 Elsevier Science B.V. All rights reserved.