Silicon carbide(SiC) has been widely concerned for its excellent overall mechanical and physical properties, such as low density, good thermal-shock behavior, high temperature oxidation resistance, and radiation resis...Silicon carbide(SiC) has been widely concerned for its excellent overall mechanical and physical properties, such as low density, good thermal-shock behavior, high temperature oxidation resistance, and radiation resistance; as a result, the SiC-based materials have been or are being widely used in most advanced fields involving aerospace, aviation, military, and nuclear power. Joining of SiC-based materials(monolithic SiC and SiCf/SiC composites) can resolve the problems on poor processing performance and difficulty of fabrication of large-sized and complex-shaped components to a certain extent, which are originated from their high inherent brittleness and low impact toughness.Starting from the introduction to SiC-based materials, joining of ceramics, and joint strength characterization, the joining of SiC-based materials is reviewed by classifying the as-received interlayer materials, involving no interlayer, metallic, glass-ceramic, and organic interlayers. In particular, joining processes(involving joining techniques and parameter conditions), joint strength,interfacial microstructures, and/or reaction products are highlighted for understanding interfacial behavior and for supporting development of application-oriented joining techniques.展开更多
分别采用熔渗(melt infiltration,MI)工艺、化学气相渗透结合前驱体浸渍裂解(chemical vapor infiltration combined with precursor infiltration and pyrolysis,CVI+PIP)工艺及前驱体浸渍裂解(precursor infiltration and pyrolysis,P...分别采用熔渗(melt infiltration,MI)工艺、化学气相渗透结合前驱体浸渍裂解(chemical vapor infiltration combined with precursor infiltration and pyrolysis,CVI+PIP)工艺及前驱体浸渍裂解(precursor infiltration and pyrolysis,PIP)工艺制备SiC_(f)/SiC复合材料,采用扫描电镜及其附带的能谱仪、X射线衍射仪等表征分析不同工艺制备的SiC_(f)/SiC复合材料在1300℃水氧环境腐蚀前后的微观结构、组成及性能变化。结果表明:不同工艺制备的复合材料氧化后断口氧元素分布有明显不同,氧化后的物相与制备工艺密切相关;经1300℃/50 h水氧腐蚀后,MI工艺制备的SiC_(f)/SiC复合材料强度保留率为84%,模量保留率为76%;CVI+PIP工艺制备的SiC_(f)/SiC复合材料强度保留率为64%,模量增加6%;PIP工艺制备的SiC_(f)/SiC复合材料强度保留率为49%,模量增加17%;MI工艺制备的复合材料表现为氧化增重,而采用CVI+PIP及PIP工艺制备的复合材料表现为氧化失重,主要与其微观结构及组成相关。展开更多
为获得性能优异的耐高温结构吸波材料,以纳米SiO_2颗粒为填料,采用有机先驱体浸渍裂解法(precursor infiltration and pyrolysis,PIP)制备SiC_f/SiC复合材料,研究填料对复合材料力学性能和高温介电性能的影响。结果表明:随着SiO_2含量从...为获得性能优异的耐高温结构吸波材料,以纳米SiO_2颗粒为填料,采用有机先驱体浸渍裂解法(precursor infiltration and pyrolysis,PIP)制备SiC_f/SiC复合材料,研究填料对复合材料力学性能和高温介电性能的影响。结果表明:随着SiO_2含量从3%(质量分数,下同)增加至15%,SiC_f/SiC复合材料的弯曲强度先增加后减小,最高可达275 MPa;低介电常数SiO_2填料的引入使得复合材料的复介电常数逐渐减小,室温吸波性能得到有效改善,15%SiO_2含量的复合材料厚度为3.2~4.0 mm时,室温反射率在整个X波段均达到–8 d B以下;复合材料的复介电常数随着温度的升高逐渐增大,而SiO_2能显著降低高温复介电常数及其增幅,700℃时15%SiO_2含量复合材料在2.7~3.0 mm厚度范围具有优异的吸波性能。展开更多
基金supported by the National Natural Science Foundation of China (No. 51572112)the National Key R&D Program of China (No. 2017YFB0310400)+3 种基金the 333 Talents Project (No. BRA2017387)Six Talent Peaks Project (No. TD-XCL-004)Innovation/Entrepreneurship Program ([2015]26)Qing Lan Project ([2016]15) of Jiangsu Province
文摘Silicon carbide(SiC) has been widely concerned for its excellent overall mechanical and physical properties, such as low density, good thermal-shock behavior, high temperature oxidation resistance, and radiation resistance; as a result, the SiC-based materials have been or are being widely used in most advanced fields involving aerospace, aviation, military, and nuclear power. Joining of SiC-based materials(monolithic SiC and SiCf/SiC composites) can resolve the problems on poor processing performance and difficulty of fabrication of large-sized and complex-shaped components to a certain extent, which are originated from their high inherent brittleness and low impact toughness.Starting from the introduction to SiC-based materials, joining of ceramics, and joint strength characterization, the joining of SiC-based materials is reviewed by classifying the as-received interlayer materials, involving no interlayer, metallic, glass-ceramic, and organic interlayers. In particular, joining processes(involving joining techniques and parameter conditions), joint strength,interfacial microstructures, and/or reaction products are highlighted for understanding interfacial behavior and for supporting development of application-oriented joining techniques.
基金Project(6142907200301) supported by the National Defense Pre-Research Foundation of ChinaProject supported by the Key Laboratory for Lightweight High Strength Structural Materials,Central South University,China。
文摘分别采用熔渗(melt infiltration,MI)工艺、化学气相渗透结合前驱体浸渍裂解(chemical vapor infiltration combined with precursor infiltration and pyrolysis,CVI+PIP)工艺及前驱体浸渍裂解(precursor infiltration and pyrolysis,PIP)工艺制备SiC_(f)/SiC复合材料,采用扫描电镜及其附带的能谱仪、X射线衍射仪等表征分析不同工艺制备的SiC_(f)/SiC复合材料在1300℃水氧环境腐蚀前后的微观结构、组成及性能变化。结果表明:不同工艺制备的复合材料氧化后断口氧元素分布有明显不同,氧化后的物相与制备工艺密切相关;经1300℃/50 h水氧腐蚀后,MI工艺制备的SiC_(f)/SiC复合材料强度保留率为84%,模量保留率为76%;CVI+PIP工艺制备的SiC_(f)/SiC复合材料强度保留率为64%,模量增加6%;PIP工艺制备的SiC_(f)/SiC复合材料强度保留率为49%,模量增加17%;MI工艺制备的复合材料表现为氧化增重,而采用CVI+PIP及PIP工艺制备的复合材料表现为氧化失重,主要与其微观结构及组成相关。
文摘为获得性能优异的耐高温结构吸波材料,以纳米SiO_2颗粒为填料,采用有机先驱体浸渍裂解法(precursor infiltration and pyrolysis,PIP)制备SiC_f/SiC复合材料,研究填料对复合材料力学性能和高温介电性能的影响。结果表明:随着SiO_2含量从3%(质量分数,下同)增加至15%,SiC_f/SiC复合材料的弯曲强度先增加后减小,最高可达275 MPa;低介电常数SiO_2填料的引入使得复合材料的复介电常数逐渐减小,室温吸波性能得到有效改善,15%SiO_2含量的复合材料厚度为3.2~4.0 mm时,室温反射率在整个X波段均达到–8 d B以下;复合材料的复介电常数随着温度的升高逐渐增大,而SiO_2能显著降低高温复介电常数及其增幅,700℃时15%SiO_2含量复合材料在2.7~3.0 mm厚度范围具有优异的吸波性能。
