For ZrO 2 -30 vol% Al 2 O 3 -30 vol% spinel, elongation-to-failure is evaluated by measuring the distance between the marker lines placed within the geometric gauge portion of tensile specimen. At strain rates of 10 - 2 -10 - 1 s - 1 , elongations exceed 2000%; a maximum elongation of 2510% is recorded at a strain rate of 0.085 s - 1 . Cavitation is significantly suppressed owing to stress relaxation at grain boundaries, which is caused by dislocation-induced plasticity in ZrO 2 grains.