BN coated whisker - reinforced silicon nitride

摘要

Thin films of boron nitride have been deposited on the surface of β-Si{sub}3N{sub}4 whiskers by dip-coating in boric acid solutions, followed by drying at room temperature, heating in nitrogen flow, and finally nitriding in an ammonia flow at 1000°C. Infrared (IR) spectroscopy, scanning electron microscopy (SEM) studies proved the formation of boron nitride surface coating. Microstructure, mechanical properties and fracture characteristics of β-Si{sub}3N{sub}4 whiskers reinforced Si{sub}3N{sub}4 and α-SiAlON matrix were investigated. The addition whiskers with BN coating increases bending strength and fracture toughness of the ceramics composite material.