Sintering Of High-Performance Silicon Nitride Ceramics Under Vibratory Pressure

To improve mechanical behaviors of silicon nitride ceramics, here we introduced a novel external field - vibratory pressure into the sintering of Si3N4 ceramics with advantages of higher density, more uniform distribution of interfacial phase, higher sintering motivation in the width direction, and therefore more favorable mechanical properties than traditional sintering methods. Grain size and aspect ratio of the two ceramics were investigated with linear intercept method. Flexural strength of the vibratory-assisted hot-pressing (VAHP) specimen increased from 936 ± 27.2 MPa to 1247 ± 28.9 MPa, and an increase of 10% was achieved in fracture toughness. It is believed that such VAHP method can provide a universal approach and new opportunities for the fabrication of covalent-bonded ceramics or composites with enhanced performances