Mechanical properties of Ce0.9Gd0.1O2-x and Ce0.9Gd0.1O2-x + Al2O3 composites.

摘要

The room-temperature elastic moduli, fracture strength, and fracture toughness of dense, fine-grained, pure Ce(sub 0.9)Gd(sub 0.1)O(sub 1.95) and composites containing 1.3 and 9.1 wt. % Al(sub 2)O(sub 3) were investigated. Addition of 9.1 wt.% Al(sub 2)O(sub 3) to Ce(sub 0.9)Gd(sub 0.1)O(sub 1.95) changed the fracture mode from intergranular to transgranular and increased room-temperature fracture strength from 65 to 125 MPa and fracture toughness from 1.3 to 1.6 MPam(sup 1/2). In addition, steady-state compressive creep was measured for Ce(sub 0.9)Gd(sub 0.1)O(sub 1.95) and the Ce(sub 0.9)Gd(sub 0.1)O(sub 2(minus)x) + 9.1 wt.% Al(sub 2)O(sub 3) composite. The stress exponent (approx)1.3 and the activation energy (approx)480 kJ/mole for Ce(sub 0.9)Gd(sub 0.1)O(sub 1.95) suggested diffusional flow controlled by the cations. There was no difference in creep rate between Ce(sub 0.9)Gd(sub 0.1)O(sub 2(minus)x) and the composite.