(1. 中南大學(xué) 粉末冶金研究院，長沙 410083；
2. 航天材料及工藝研究所 先進(jìn)功能復(fù)合材料技術(shù)重點(diǎn)實(shí)驗(yàn)室，北京 100076)
摘 要: 為了滿足高超音速飛行器熱結(jié)構(gòu)部件材料的需求，采用化學(xué)氣相沉積法(CVD)和反應(yīng)熔滲法(RMI)混合工藝制備了疊層縫合C/C-SiC復(fù)合材料，研究C/C多孔體密度和熔滲溫度對(duì)C/C-SiC復(fù)合材料微觀結(jié)構(gòu)和彎曲性能的影響。結(jié)果表明：C/C多孔體孔徑呈雙峰分布，孔體積隨C/C多孔體密度增加而降低。C/C-SiC 復(fù)合材料由 SiC、C 及殘余 Si 相組成。C/C-SiC復(fù)合材料彎曲強(qiáng)度隨熔滲溫度的升高而增加；1650 ℃制備的C/C-SiC復(fù)合材料彎曲強(qiáng)度隨C/C多孔體密度升高先增加后略有減小，而1750 ℃制備C/C-SiC復(fù)合材料彎曲強(qiáng)度隨C/C多孔體密度升高而升高。當(dāng)C/C多孔體密度為1.55 g/cm3，熔滲溫度為1750 ℃時(shí)，制備的C/C-SiC復(fù)合材料彎曲強(qiáng)度最高為253 MPa。在彎曲載荷作用下，C/C-SiC復(fù)合材料的位移-載荷曲線呈現(xiàn)“階梯型”斷裂行為。
關(guān)鍵字: C/C-SiC；疊層縫合結(jié)構(gòu)；熔滲溫度；C/C多孔體密度；彎曲強(qiáng)度
（1. Powder Metallurgy Research Institute, Central South University, Changsha 410083, China;
2. Science and Technology of Advanced Functional Composite Materials Laboratory, Aerospace Research Institute of Materials and Processing Technology, Beijing 100076, China）
Abstract:In order to meet the requirements of materials for hypersonic aircraft thermal structure components, the laminated suture structure C/C-SiC composites were prepared by mixed process of chemical vapor deposition (CVD) and reactive melt infiltration (RMI), the influence of C/C porous bodies density and infiltration temperature on the microstructure and flexural properties of C/C-SiC composites was investigated. The results show that the pore size of the C/C porous bodies has a bimodal distribution, and the pore volume decreases with the increase of the density of the porous bodies. C/C-SiC composites are composed of SiC, C and residual Si phases. The flexural strengths of C/C-SiC composites increase with the increase of infiltration temperature. The flexural strength of C/C-SiC composites prepared at 1650 ℃ firstly increases and then decreases slightly with the raise of C/C porous bodies density. At 1750 ℃, the flexural strength increases as the density of the C/C porous bodies increases. The maximum flexural strength of C/C-SiC composites is 253 MPa when the density of C/C porous is 1.55 g/cm3 and the infiltration temperature is 1750 ℃. Under the flexural loads, the displacement-load curves of C/C-SiC composites show a “stepped” fracture behavior.
Key words: C/C-SiC; laminated suture structure; infiltration temperature; C/C porous bodies density; flexural strength
