Numerical Simulation Of Thermal Residual Stresses In Titanium Matrix Composites

Two kinds of thermal residual stresses exist in metal matrix composites(MMC). One of them is temperature gradient induced thermal stresses caused by temperature gradient in MMC. The other can develop upon cooling from the processing temperature to room temperature due to the coefficient of thermal expasion(CTE) mismatch between the fiber and matrix and is called CTE mismatch induced thermal stresses. Obviously, CTE mismatch induced thermal stresses is one of the biggest characteristic in MMC because CTE mismatch is usually very serious in most of MMC. So this question must be solved at first.A variety of factors which influence CTE mismatch induced thermal stresses such as fiber array, temperature dependent material properties, composites fabrication temperature and pressure has been discussed. On the other hand, the temperature gradient induced thermal stresses is also analysed and factors such as heat treatment conditions, composites fabrication temperature and pressure to influence the stresses are investigated. By these research work we attempt to sum up two kinds of thermal residual stresses and look for appropriate composites fabrication and heat treatment parameter.Because there are many kinds of matrixes in titanium matrix composite, we select some typical ones as investigated subject in many titanium alloys or titanium aluminide intermetallics, and then simulate the distribution of thermal residual stresses under the appropriate composites fabrication and heat treatment parameter. We not only hope to seek better titanium matrix, but also discover the relationship between the material properties and the thermal residual stresses, and then provide some theoretical guidance for the selection of the matrix in titanium matrix composites.