A novel oxide composite reinforced with a ductile phase for very high temperature structural materials

The strength of nearly all metallic and ceramic polycrystalline materials d rops off rapidly with increases in temperature. Here we have developed a st rong and tough oxide composite reinforced with a ductile phase at 1873 K wi th a different kind of microstructure, made by unidirectional solidificatio n of an Al2O3-Y3Al5O12(YAG)-ZrO2 ternary eutectic mixture. this composite h as a microstructure in which continuous networks of single-crystal Al2O3, s ingle-crystal YAG and single-crystal c-ZrO2 interpenetrate without grain bo undaries. No amorphous phases are observed at the interfaces between these phases and relatively compatible interfaces are formed. This material displ ays plastic deformation at 1873 K indicating high yielding flexural strengt h. This composite's average flexural strength at 1873 K of around 850 MPa - approximately 57 times higher than that of the sintered composite with the same composition, and its ductile fracture at 1873 K have never been found up to now. Consequently several useful applications can be considered in m echanical engineering.