| 摘要 |
PURPOSE:To improve an anti-spalling property against repeated thermal shock to a silicon nitride sintered body by sintering a molded body composed of the specific ratio of the metallic silicon powder, the hexagonal boron nitride powder, the metallic fiber incorporating aluminum in the gaseous nitrogen atmosphere. CONSTITUTION:An organic binder such as acrylic resin is added into 5-95 wt.% metallic silicon powder, 3-90 wt.% hexagonal boron nitride powder, 0.2-4.0 wt.% metallic fiber incorporating aluminum and mixed with a wet system using a solvent such as methanol. Then it is dried, pulverized and blended and press molded. This molding body is sintered in an N2 atmosphere. By mixing a small amount of hydrogen into nitrogen, the nitridation reaction of the metallic silicon is accelerated. The above-mentioned fiber is reacted with the metallic silicon powder and nitrogen and the reactive layer is formed with silicon nitride which is a matrix after the sintering. By this means, in the structure of the sintered body an acicular structure is introduced into fine silicon nitride and boron nitride and the anti-spalling property is improved. |
