微孔挤压技术制备SiC_w补强CMAS玻璃陶瓷基复合材料

PREPARATION OF SiC w REINFORCED CMAS GLASS_CERAMIC MATRIX COMPOSITE BY MICRO_HOLE EXTRUSION TECHNIQUE

通过微孔挤压技术成功地制备了含有ＳｉＣｗ补强的钙－镁－铝的硅酸盐（ＣＭＡＳ）玻璃陶瓷基复合材料．ＳｉＣｗ加入到已球磨好的ＣＭＡＳ粉末与有机添加剂的浆料中，得到ＳｉＣｗ分散均匀的混合浆料．含有机添加剂仅为７％左右的浆料就可在较低的压力下（２．３７ｋＰａ）挤压通过微孔（＝２５０μｍ），获得ＳｉＣｗ分散均匀并高度取向的纤维状生坯．晶须高度取向补强增加了ＣＭＡＳ的强度，含晶须１０％的ＣＭＡＳ通过无压烧结可以制备出高致密度的复合材料．

SiC w reinforced CMAS glass_ceramic composite was fabricated successfully by micro_hole extrusion technique. The mixture of PAN, DMF and CMAS was homogenized by ball_milling, SiC w was immersed into DMF and ultrasonically dispersed in a separate container, then SiC w was filtered out and the cake was added into the powder slurry. Stirring for 60 min was adequate to produce a homogeneous paste. The paste was wet_spun using a laboratory spinning apparatus. Continuous fiber will be easily extruded at a low extrusion pressure (2.37 kPa)through a small orifice (250 μm). Only normal sintering gives a nearly, fully dense glass_ceramic composite. The oriented whisker in the glass_ceramic matrix increases the strength of the material remarkably.