注射成形制备碳化硅异形件的工艺研究

STUDY OF FABRICATION OF SILICON CARBIDE IRREGULAR SHAPE PARTS BY INJECTION MOLDING

通过注射成形工艺可以成功制备碳化硅陶瓷异形件,其关键在于碳化硅微粉粒度的大小、分布和粉体形状的选取,烧结助剂的粒度组成和添加量,合理的脱脂和烧结工艺等。研究发现,选取平均粒度为0.58μm、球形和不规则形状混合的碳化硅微粉,添加10%的5μmAl2O3,4μmY2O3粒度组成的烧结助剂,可以制备出合格的坯体,再经10h溶脱和热脱工艺后,将坯体埋于填料中,于1 900℃保温30 min进行液相烧结,就可以得到相对密度为98.2%的碳化硅陶瓷异形件。

Silicon carbide ceramic parts of irregular shape can be successfully fabricated by injection molding process. The key technique is determination of optimum size distribution and shape of silicon carbide particles, size distribution and quantity of sintering additives,reasonable debinding and sintering process. It was found that the qualified injection moldel green compacts could be prepared by using a mixture of spherical and irregular shape silicon carbide with an average size of 0.58 μm and sintering the compacts at 1 900,for 30 min,under argon atmosphere after 10 h solution debinding and thermal debinding. The irregular shape parts of silicon carbide with a relative density of 98.20% could be produced finally.