THERMAL-EXPANSION OF TIAL+TIB2 ALLOYS AND MODEL-CALCULATIONS OF STRESSES AND EXPANSION OF CONTINUOUS FIBER COMPOSITES

Thermal expansion values for three TiAl alloys with different additions of TiB2 can be represented using a third-order equation at temperatures between 20 and 800-degrees-C. Expansion values were obtained on both heating and cooling temperature cycles. The total expansion at 800-degrees-C is between 0.917 and 0.931% for three different samples. The expansivity increases from about 10 x 10(-6) degrees-C-1 at 80-degrees-C to 14 x 10(-6) degrees-C-1 at 750-degrees-C. A five-coaxial cylinder elastic model for multizone-coated continuous fiber composites is developed for predicting stresses and thermal expansion of composites. Either isotropic or transversely isotropic material properties can be assigned to the various cylinder zones.