No abstract

We report here about the effect of rare‐earth dopants on the improvement of room‐temperature mechanical properties of alumina. Rare‐earth ions (RE = Yb3+, Er3+, and La3+) of different ionic radii in a minimum concentration of 1000 ppm were added as dopants individually to high‐purity alumina and densified by pressureless sintering. High strength of about 700 MPa was attained for Yb‐doped alumina sintered at 1400°C. And, high toughness of about 7.0 MPa·m1/2 was attained for Er‐ and La‐doped alumina samples.

No abstract

No abstract

The pulse electric current sintering technique (PECS) was demonstrated to be effective in rapid densification of fine‐grained Al2O3/3Y‐ZrO2 using available commercial powders. The composites attained full densification (>99% of TD) at 1450°C in less than 5 min. The composites sintered at a high heating rate had a fine microstructure. The incorporation of 3 vol% 3Y‐ZrO2 substantially increased the average fracture strength and the toughness of alumina to as high as 827 MPa and 6.1 MPa·m1/2, respectively. A variation in the heating rate during the PECS process influenced grain size, microstructure, and strength, though there was little or no variation in the fracture toughness.