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采用原位反应无压浸渗工艺,制备了Si C/Al双连续相复合材料,研究烧结温度对Si C/Al双连续相复合材料的导热性能的影响,观察Si C/Al双连续相复合材料的表面形貌。结果表明:Al合金熔体在无压下能渗入三维网状Si C多孔陶瓷孔隙,形成组织均匀具有网络贯穿结构的Si C/Al双连续相复合材料。浸渗温度对复合材料的导热系数影响很大,当浸渗温度为900、1000、1100和1200℃时,复合材料室温下的导热系数分别为167.4、160、154和152 W/(m·K),与浸渗温度900℃相比,浸渗温度1200℃复合材料室温下的导热系数下降了9%。因此,在保证浸渗完全的情况下,随着浸渗温度的升高,复合材料的导热性能越来越差,这主要是由于高温下熔融Al液与Si C陶瓷之间发生界面反应所致;适当地降低熔渗温度可以减缓界面反应的程度,从而提高复合材料的导热性能。本实验的最佳工艺条件为N2气氛,900℃保温3 h。
The effect of sintering temperature on the thermal conductivity of Si C / Al bicontinuous phase composites was investigated by in situ reactive pressureless infiltration process. The effect of Si C / Al bicontinuous phase composite Surface morphology of the material. The results show that the Al melt can infiltrate into the pores of the three-dimensional network of Si C porous ceramics under pressureless condition to form Si C / Al bicontinuous composite with uniform network structure. The infiltration temperature has a great influence on the thermal conductivity of the composites. The thermal conductivities of the composites at room temperature of 900, 1000, 1100 and 1200 ℃ are 167.4, 160, 154 and 152 W / (m · K ). Compared with the infiltration temperature of 900 ℃, the thermal conductivity of the composites at the infiltration temperature of 1200 ℃ decreased by 9% at room temperature. Therefore, under the condition of complete infiltration, the thermal conductivity of the composites is getting worse with the increase of infiltration temperature, which is mainly attributed to the interfacial reaction between molten Al liquid and Si C ceramics at high temperature Properly reducing the infiltration temperature can reduce the degree of interfacial reaction and thus improve the thermal conductivity of the composite. The best experimental conditions for the N2 atmosphere, 900 ℃ insulation 3 h.