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1.前言烧蚀是一种保护热敏感结构不受外界高温的灾难性影响的有效、可靠的方法。此方法适用于结构物在有限的时间内需要保护的场合,如宇航领域等。烧蚀通常指物体表面的物质在热气流作用下的损耗。这种损耗可通过熔解、蒸发、热解燃烧和机械磨损来实现。尽管已使用了渗钨钼和陶瓷,但作为烧蚀材料用得最多的还是聚合物或含有聚合物的复合材料。这是由于聚合物具有优良的性能,如低密度、低热传导系数、高比热以及可控制的产生低分子气体的分解。
1. Introduction Ablation is an effective and reliable method of protecting heat-sensitive structures from the catastrophic effects of high temperatures outside. This method is suitable for structures that need protection for a limited time, such as aerospace. Ablation usually refers to the surface of the object material under the action of hot air loss. This loss can be achieved by melting, evaporating, pyrolytic burning and mechanical wear. Although infiltrated molybdenum and ceramics have been used, polymers or polymer-containing composites are the most used as ablative materials. This is due to the polymer’s excellent properties such as low density, low thermal conductivity, high specific heat and controllable decomposition of low-molecular-weight gases.