目的 研究不同氧化物添加剂对Si C-Zr C涂层C/C复合材料相组成、微观结构和抗氧化性能的影响。方法 采用包埋法,分别以Al2O3,B2O3和Mg O作为添加剂,制备Si C-Zr C涂层C/C复合材料,分析相组成及微观结构,考察复合材料在1000~1550℃静态空气气氛中的抗氧化性能。结果 以Al2O3作为包埋添加剂制得的涂层致密,而以Mg O为添加剂制得的涂层较疏松。在1000~1550℃的静态空气气氛中,随着氧化温度的升高,以Al2O3为添加剂制得的复合材料失重率逐渐减小,在1550℃氧化1 h后仅为1%;以B2O3和Mg O为添加剂制得的复合材料失重率逐渐增加,在1550℃氧化1 h后分别达到15%和36%。结论 与B2O3添加剂相比,Al2O3和Mg O添加剂更能促进包埋粉料的扩散。以Al2O3作为包埋添加剂制得的Si C-Zr C涂层C/C复合材料具有较好的高温抗氧化性能。
Objective To investigate the effect of different oxide additives on the phase composition, microstructure and oxidation resistance of the SiC-ZrC coated C/C composites. Methods SiC-ZrC coated C/C composites were prepared by a pack cementation technique with different oxides (A1203 , B203 or MgO) as additives. The anti-oxidation property of the SiC-ZrC coated C/C composites was also studied in the temperature range between 1000 ℃ and 1550 ℃in static air. Results The results showed that AI: 03 and MgO additives exhibited better performance in enhancing the diffusion of the embedding powder materials than B2O3 additive. The SiC-ZrC coating prepared with AI203 as an additive was more compact than that prepared with MgO as an additive. The weight loss of the SiC-ZrC coated C/C composites prepared with Al2O3 as an additive decreased gradually with the increasing oxidation temperature in the temperature range of 1000 ~ 1550 ℃, and the weight loss was about 1% after oxidation at 1550 ℃for 1 h in air. However, the weight loss of the SiC-ZrC coated C/C composites prepared with B2 03 or MgO as an additive increased with the increase of the oxidation temperature. After oxidation for 1 h, the weight loss of the composites prepared with B203 and MgO as additives reached 15% and 36%, respectively. Conclusion The SiC-ZrC coated C/C composites prepared with Al2O3 as an additive had good oxidation resistance at high temperature.