论文部分内容阅读
在炭材料表面通过莫来石（３Ａｌ２Ｏ３·２ＳｉＯ２）或锆石（ＺｒＳｉＯ４）氧化物薄膜涂层与ＳｉＣ的浓度梯度薄层结合，成功地获得了在空气流中１４００℃下的高抗氧化性能。在１４５０℃时，采用将炭材料直接浸入熔融Ｓｉ金属形成ＳｉＣ浓度梯度，通过溶胶－凝胶过程形成锆石和莫来石氧化薄膜。水解速率的控制是产生均匀薄膜的关键。具有ＳｉＣ浓度梯度和莫来石涂层的各向同性高密度石墨块足以在空气中１４００℃下抗氧化和１４００℃到液氮温度下抗淬火。莫来石涂层比锆石涂层更有效。
The high oxidation resistance at 1400 ° C in the air stream was successfully achieved by combining a thin layer of SiC concentration gradient with a mullite (3Al 2 O 2 · 2SiO 2) or zircon (ZrSiO 4) oxide film coating on the surface of the carbon material. At 1450 ℃, the carbon material was directly immersed in molten Si metal to form a SiC concentration gradient, and zircon and mullite oxide films were formed by the sol-gel process. The control of the hydrolysis rate is the key to producing a uniform film. An isotropic high density graphite block with SiC concentration gradient and mullite coating is sufficiently resistant to oxidation at 1400 ° C in air and to quench at 1400 ° C to liquid nitrogen temperature. Mullite coatings are more effective than zircon coatings.