Mechanical properties of fully dense yttrium aluminum garnet (YAG) ceramics

The mechanical properties of yttrium aluminum garnet (YAG) ceramics were studied at the temperature range of 1100°C to 1250°C using three-point flexure tests. This experiment was conducted on YAG ceramics (YAG(A) and YAG(B)) having a different average grain size. YAG(A) had an average grain size of 1.04 μm, while YAG(B) had an average grain size of 1.54 μm. In the case of crosshead speed of 1 mm/min, YAG(A) and YAG(B) failed in a brittle manner at temperatures up to 1250°C, and had a strength of 500-600 MPa. In the case of crosshead speed of 0.0016 mm/min, YAG(A) failed in a brittle manner at temperatures up to 1100-1150°C, and had strength of 500-600 MPa, but exhibited plastic deformation at 1200°C. On the other hand, YAG(B) failed in a brittle manner at temperatures up to 1150-1200°C, and had strength of about 700 MPa, but exhibited plastic deformation at 1250°C.