富氧度和粒子浓度对硅橡胶绝热材料烧蚀行为影响对比

Comparative Study on the Effect of Oxygen-rich Condition and Particle Concentration on Ablation Behavior of Silicone Rubber Insulation Materials

为探究富氧度和粒子浓度对硅橡胶绝热材料烧蚀行为影响机理间的联系,基于自主研发的氧-煤油烧蚀试验系统,对某型硅橡胶基绝热材料进行了烧蚀试验。试验共设计有0%、5%、9%、15%、20%5组富氧度条件,每组均设置4%、6%、8%、10%4类粒子浓度,试验后测算各试样烧蚀率,并绘制了烧蚀率、富氧度和粒子浓度的三维曲面图,同时利用扫描电镜(SEM)对试样进行微观形貌研究。结果表明:在试验参数范围内,当富氧度一定时,随粒子浓度的增加,材料的2类烧蚀率均有所增大;而粒子浓度不变时,材料烧蚀率随富氧度的增加先上升后下降,在9%左右达到极值;粒子浓度直接影响材料表面的机械受力状况;富氧度影响材料中SiO_2的生成速率,在低富氧度条件下,SiO_2的生成析出量无法全面包裹保护纤维,致使烧蚀率略有上升;而在高富氧度条件下,生成的SiO_2附着在纤维丝表面加强了耐冲蚀性能,减缓了粒子破坏;粒子浓度对材料烧蚀行为的影响大于富氧度对材料烧蚀行为的影响,在开展的实验条件下,约是富氧度影响的5倍。

In order to investigate the influence mechanism of oxygen-rich condition and particle concentration on the ablation behavior of silicone rubber insulation,the ablation test of a certain type of silicone rubber based insulation material is carried out based on the self-developed oxygen-kerosene ablation test system.A total of 0%,5%,9%,15% and 20% of the oxygen-rich conditions are designed,and each group is set with 4%,6%,8%and 10% particle concentration.The ablation rate of each sample is measured and the ablation rate,oxygen-rich condition and particle concentration are plotted.At the same time,the microstructure of the sample is analyzed by scanning electron microscopy（SEM）.The results show that the ablation rate of the two kinds of materials increases with the increase of the particle concentration when the oxygen-rich condition is constant.When the concentration of particles is constant,the ablation rate of ma-terials increases first and then decreases with the increase of oxygen-rich condition and reaches the extreme at around 9% of the oxygen-rich condition;Particle concentration directly affects the mechanical stress of the surface of the material.The oxygen-rich condition affects the formation rate of SiO2 in the material.Under conditions of low degree of oxygen-rich,the amount of SiO2 could not be encapsulated in the protective fiber,resulting in a slight increase in ablation rate.And under conditions of high degree of oxygenrich,the generated SiO2 adhered to the surface of the filament,strengthens the erosion resistance and slows down the particle destruction.The effect of the particle concentration on the ablation behavior of the material is greater than that of the oxygen-rich condition on the ablation behavior of the material,which is about 5 times the degree of the influence of oxygen-rich condition under conditions of the experiments.