关键词: 织构陶瓷;高取向度;BN;力学性能

Abstract: On the basis of plate-like BN powder,textured BN ceramics were prepared by tape casting combined with hot-pressing technique.By means of XRD,SEM and universal mechanical tester, the structure, fracture surface morphology and mechanical properties of the BN ceramics were studied.Experimental results reveal that the BN grains exhibit preferred orientation along (002) plane.Textured BN ceramics show significantly anisotropic mechanical properties:when the loading direction perpendicular to the lamellar, bending strength and fracture toughness are respectively 53.75 MPa and 1.51 MPa·m1/2, which are superior to the mechanical properties in horizontal direction.Good performance in the vertical direction can be attributed to the crack deflection induced by plate-shaped particles.

Key words: On the basis of plate-like BN powder,textured BN ceramics were prepared by tape casting combined with hot-pressing technique.By means of XRD,SEM and universal mechanical tester, the structure, fracture surface morphology and mechanical properties of the BN ceramics were studied.Experimental results reveal that the BN grains exhibit preferred orientation along (002) plane.Textured BN ceramics show significantly anisotropic mechanical properties:when the loading direction perpendicular to the lamellar, bending strength and fracture toughness are respectively 53.75 MPa and 1.51 MPa·m1/2, which are superior to the mechanical properties in horizontal direction.Good performance in the vertical direction can be attributed to the crack deflection induced by plate-shaped particles.