文章信息/Info

Title:

 Oxidation Behavior and Ablation resistance of C/C-ZrC-SiC Composites Prepared by Polymer Infiltration and Pyrolysis

作者:

莊磊; 付前剛*; 李賀軍; 張佳平

西北工業(yè)大學(xué) 超高溫復(fù)合材料重點實驗室 碳/碳復(fù)合材料工程技術(shù)研究中心

Author(s):

Zhuang Lei; Fu Qiangang*; Li Hejun; Zhang Jiaping

C/C Composites Research Center, Northwestern Polytechnical University

關(guān)鍵詞:

FONT-FAMILY: ’Calibri’; ’sans-serif’">C/C-ZrC-SiC 復(fù)合材料' target="_blank" rel="external"> FONT-FAMILY: 宋體">復(fù)合材料; 氧化; 熱重

DOI:

10.7502/j.issn.1674-3962.2015.06.02

文獻(xiàn)標(biāo)志碼:

A

摘要:

采用熱梯度化學(xué)氣相滲透和聚合物浸漬裂解法制備了 ZrC-SiC 改性 C/C 復(fù)合材料（ C/C-ZrC-SiC ），借助 SEM 、 XRD 等手段研究了該復(fù)合材料的微觀形貌與相組成，并對其在 1500 ℃恒溫靜態(tài)空氣環(huán)境、室溫至 1400 ℃變溫過程的氧化行為以及氧乙炔抗燒蝕性能進(jìn)行了研究。結(jié)果表明：室溫至 1400 ℃動態(tài)氧化時 C/C-ZrC-SiC 復(fù)合材料表現(xiàn)為增重→緩慢失重→劇烈失重→穩(wěn)定四個過程；在 1500 ℃ 靜態(tài)氧化時，C/C-ZrC-SiC表現(xiàn)為增重→緩慢失重→動態(tài)穩(wěn)定→劇烈失重→穩(wěn)定五個過程。ZrC和SiC優(yōu)先氧化分別生成ZrO2骨架和SiO2玻璃層包裹基體和碳纖維，一定程度上減緩了基體和碳纖維的氧化。經(jīng)過1200 s氧乙炔燒蝕，材料線燒蝕和質(zhì)量燒蝕率分別為9.27×10-4 mm?s-1和6.67×10-4 g?s-1。在燒蝕過程中，試樣表面能形成一個ZrO2外層/SiO2內(nèi)層的雙層結(jié)構(gòu)保護膜。ZrO2骨架層能減緩燒蝕火焰對材料內(nèi)部的熱力學(xué)和熱化學(xué)燒蝕，而致密的SiO2層能夠彌合材料的裂紋、孔洞等缺陷，阻擋有氧氣氛進(jìn)一步進(jìn)入材料內(nèi)部，使材料表現(xiàn)出優(yōu)異的抗燒蝕性能。

Abstract:

C/C-ZrC-SiC-ZrB2 composites were prepared by thermal gradient chemical vapor infiltration (TCVI) and precursor infiltration and pyrolysis (PIP) process. The microstructures and phase compositions of C/C-ZrC-SiC composites after oxidation were analyzed by scanning electron microscopy and X-ray diffraction, respectively. Isothermal oxidation behavior at 1500 ℃, dynamic oxidation behavior from room temperature to 1400 ℃ and long-term ablation resistance of the composites were investigated. The results show that dynamic oxidation behavior from room temperature to 1400 ℃ could be divided into four stages: mass gain, slow mass loss, severe mass loss and constant. While the isothermal oxidation behavior of C/C-ZrC-SiC at 1500 ℃ could be divided into five stages: mass gain, slow mass loss, constant, severe mass loss and constant. ZrC and SiC trend to be oxidized preferentially and generate ZrO2 and SiO2, which wrap and protect C/C matrix and fibers partly. After ablated for 1200 s by oxyacetylene flame, the linear and mass ablation rates of composites were 9.27×10-4 mm?s-1 and 6.67×10-4 g?s-1, respectively. ZrO2 and SiO2 were formed by the oxidation of ZrC and SiC, respectively. ZrO2 can alleviate the thermal-physical and thermal-chemical erosion caused by the oxyacetylene torch, and dense SiO2 glassy film can seal the defects such as cracks and holes, leading to a good ablation resistance of C/C-ZrC-SiC composites.