熔渗温度和时间对 C/C-SiC-ZrC 复合材料性能的影响研究

目的研究熔渗温度和熔渗时间对复合材料密度和弯曲性能的影响。方法采用化学气相渗透法(CVI)和聚合物浸渍裂解法(PIP)制备熔渗用低密度C/C复合材料,以Si0.9-Zr0.1合金为熔渗金属,采用反应熔渗法(RMI)制备C/C-SiC-ZrC复合材料。测试C/C-SiC-ZrC复合材料的开孔率、密度、弯曲强度,分析试样的相组成。结果熔渗温度为1450℃时,复合材料的密度仅有1.97 g/cm3,弯曲强度仅为153 MPa;当熔渗温度升高到1550℃时,密度和弯曲强度分别升高到2.39 g/cm~3和260 MPa;而当熔渗温度升高到1650℃时,密度和弯曲强度又分别降为2.18 g/cm~3和208 MPa。1.5 h熔渗时复合材料的密度值最大,为2.46 g/cm~3,相对0.5 h熔渗的最小值提高了5.1%;1.0 h熔渗时复合材料材料的弯曲强度最高,达到了260 MPa,相对于1.5 h熔渗的最低值仅提高了3.2%。结论复合材料的致密度和弯曲强度随熔渗温度的升高先升高后降低,密度随熔渗时间的延长而增大,而弯曲强度随熔渗时间的延长先升高后降低,但密度和弯曲强度随熔渗时间的延长变化较小。

Effects of Infiltration Temperature and Time on the Properties of C/C-SiC-ZrC Composites Fabricated by RMI

Objective To investigate the effects of infiltration temperature and infiltration time on the density and flexural strength of C/C-SiC-ZrC composite.Methods Carbon fiber felt was firstly infiltrated by Chemical Vapor Infiltration (CVI) combined with Precursor Infiltration Pyrolysis (PIP) to obtain the porour C/C perform, and then Carbon fiber reinforced car-bon-silicon carbide-zirconium carbide (C/C-SiC-ZrC) composites were prepared by Reactive Melt Infiltration (RMI) with Si0.9-Zr0.1 alloy. The opening rate, density and flexural strength of C/C-SiC-ZrC composite were tested.Results The density of C/C-SiC-ZrC composite was only 1.97 g/cm3, and the flexural strength was only 153 MPa with the infiltration temperature of 1450℃. While the infiltration temperature rose to 1550℃, the density and flexural strength increased respectively to 2.39 g/cm3 and 260 MPa. With the infiltration temperature further rose to 1650℃, the density and flexural strength decreased re-spectively to 2.18 g/cm3 and 208 MPa. When the infiltration time was 1.5 hours, the density of 2.46 g/cm3 was the highest, in-creased by 5.1% than the density with the infiltration time of 0.5 hour. While the infiltration time was 1.0 hour, the highest flex-ural strength was 260 MPa, increased by only 3.1% than the flexural strength with the infiltration time of 1.5 hours. Conclusion The density and flexural strength of C/C-SiC-ZrC composites increased firstly and then decreased with the increase of infiltra-tion temperature. With the increase of infiltration time, the density of C/C-SiC-ZrC composites increased, but the flexural strength increased firstly and then decreased. The influence of infiltration time was relatively small.