Thermal expansion and deformation behaviour of aluminium-matrix composites in laser forming

In this paper, the influence of reinforcement volume fraction on the thermal expansion behaviour and bending angle of two metal-matrix composites, Al2024/15SiC(p) and Al2024/20SiC(p), in laser bending has been examined. It is found that under the same processing conditions a larger bending angle is obtained for the composite with 15% reinforcement. Three simple models have been used to predict coefficients of thermal expansion (CTE) of the composites. It is revealed that the agreement with experimental low-temperature CTEs is closer to the Turner model. At high temperature, the Kerner model is in better agreement with the experimental CTEs. On the basis of the Kerner model and a modified two-layer theoretical model for laser bending, the trend of the predicted bending angle is found to be consistent with the experimental findings. (C) 2001 Elsevier Science Ltd. All rights reserved.