浸渍浆料对先驱体转化C_f/SiC复合材料结构及性能的影响

Effect of Slurries on the Microstructure and Mechanical Properties of C_f/SiC Composites via Precursor Pyrolysis

采用先驱体转化法,以聚碳硅烷/二甲苯、聚碳硅烷/二甲苯/碳化硅粉、聚碳硅烷/交联剂三种浆料体系分别浸渍增强体,裂解制备Cf/SiC复合材料,考察了浸渍浆料体系对Cf/SiC复合材料的结构和性能的影响。研究发现:聚碳硅烷/交联剂浆料制备复合材料所需周期最短,9个周期即可制得密度达1.78g.cm-3、开孔率为4.95%的复合材料;聚碳硅烷/二甲苯/碳化硅粉制备的复合材料密度最大,达1.87g.cm-3,并且制备的复合材料表面平整光洁;聚碳硅烷/二甲苯浆料制备的Cf/SiC复合材料力学性能最好,弯曲强度达455.9MPa,模量达90.6GPa,断裂韧性达18.9MPa.m1/2。研究结果表明,三种常用的浸渍浆料制备的复合材料各有其优点,在各个浸渍周期合理的选用浆料能有效的改善材料结构及性能。

Cf/SiC composites were fabricated by Precursor Infiltration and Pyrolysis（PIP） with three different slurries. This paper studied the effects of the slurries on the microstructure and mechanical properties of their composites. It is pointed that the composites infiltrated with the slurry of PCS/ cross-linking agent had a density of 1.78g · cm^-3 and a open porosity of 4.95%, and its fabrication was only made of 9 times of infiltration and pyrolysis; The second composites infiltrated with PCS/ Xylene/SiC had the highest density of 1.87g · cm^-3 with smooth surface; And the last composites took on outstanding mechanical properties, the values of flexural strength, flexural modulus and fracture toughness were 455.9MPa, 90. 6GPa and 18.9 MPa · m^1/2 respectively. The results indicate that different slurries have different advantages, the composites could obtain the best characteristic if it was infiltrated with the most appropriate slurry in every fabrication circles.