抄録
The stresses generated as a result of difference in thermal expansion coefficient between matrix and fiber have been calculated on the heating and cooling processes of the γ-Al2O3 continuous fiber reinforced Al composite with 50 vol% fibers.
A method used for calculating the thermal stresses was based on Garmong's one which had been discussed by Tyson. In the present study, on the process of heating the composite from low temperatures the Bauschinger effect of the matrix due to the plastic deformation received during the previous thermal history was incorporated into the constitutive equation for the Al matrix. As for the matrix creep at high temperatures, the Dorn formulation for steady-state creep of polycrystalline Al was used on the assumption that the creep stress contains a threshold stress below which the matrix creep can not take place. The analysis of the matrix stress relaxation at high temperatures indicated that a considerable degree of the threshold stress must be taken into account.
The matrix thermal stress-temperature hysteresis curves were observed by an X-ray diffraction technique during the thermal cycling processes of the composite. The thermal stresses calculated on the basis of the present model were in good agreement with the experimental results.
