硅橡胶基防热涂层高温压缩行为  

Compressive Behavior of Silicone Rubber Based Thermal Protective Coating Under High Temperature

作　　者：严旭 王洪波[2] 范新中[1] 梁祖典 樊虎 YAN Xu;WANG Hongbo;FAN Xinzhong;LIANG Zudian;FAN Hu(Tactical Weapons Division,China Academy of Launch Vehicle Technology,Beijing 100076;China Academy of Launch Vehicle Technology,Beijing 100076;The Third Military Representative Office of Air Force Equipment Department in Beijing Region,Beijing 100076)

机构地区：[1]中国运载火箭技术研究院战术武器事业部,北京100076 [2]中国运载火箭技术研究院,北京100076 [3]空装驻北京地区第三军事代表室,北京100076

出　　处：《宇航材料工艺》2020年第4期49-54,共6页Aerospace Materials & Technology

摘　　要：为研究硅橡胶基防热涂层高温下的力学性能,针对两种硅橡胶基防热涂层开展高温压缩试验,对其截面的宏观及微观形貌进行分析,并结合高温下的热失重分析,探讨了其高温压缩强度变化规律及机理。研究结果表明:甲基苯基硅橡胶涂层高温热解温度区间主要为500~650℃,最终质量残余率为67.61%,其高温压缩强度在25~800℃呈增加趋势,由于玻璃小球的软化及树脂基体的热解,导致在400及700℃两个温度点的压缩强度降低,但在800℃由于玻璃小球与涂层中填料、烧蚀产物等发生共融,使涂层力学性能显著增加。甲基乙烯基硅橡胶涂层的高温热解温度区间主要为450~800℃,最终质量残余率为89.95%,由于甲基乙烯基硅橡胶涂层在高温热解后产生的陶瓷相,弥补了树脂裂解所带来的强度下降,因此在25~800℃其高温压缩强度较为稳定,并未产生明显衰减。影响硅橡胶基防热涂层高温力学性能的因素主要包括树脂基体的热解以及填料在高温下发生的物理-化学变化。In order to investgate the mechanical properties of silicone rubber based coatings at high temperatures,two types of silicone rubber based thermal protective coatings were investigated by high temperature compression tests.The macroscopic morphology and microstructure of the compression sections after high temperature compression were observed. Combined with the analysis of thermal weight loss at high temperature,the mechanism of thermo-mechanical property change was discussed. The results show that the thermal pyrolysis temperature range of methyl phenyl silicone rubber based coating is mainly about 500 to 650 ℃,and the final mass residual rate is 67. 61%. The compressive strength increases with the temperature from 25 to 800 ℃. The strength has a decrease from 400 to 700 ℃ beacuse of the softening of the glass microsphere and the thermal pyrolysis reaction of the silicone rubber. At 800 ℃,the compression strength reaches significant increase as a result of the co-melting of glass microsphere,reinforcing fillers and the ablation products.The thermal pyrolysis reaction temperature range of methyl vinyl silicone rubber based coating is 450 to 800 ℃,and the final mass residual rate is 89. 95%. After thermal pyrolysis reaction,methyl vinyl silicone rubber transforms from organic to new ceramic phase,which prevents the decrease of the strength caused by resin pyrolysis. Thus the thermo-mechanical properties of methyl vinyl silicone rubber based thermal protective coatings stay steady from 25 to 800 ℃. The mechanism analysis indicates that the main influencing factors of thermo-mechanical properties are pyrolysis of resin matrix and physicochemical changes of fillers under high temperature conditions.

关 键 词：硅橡胶基防热涂层 树脂基体 高温力学性能 热解机理 

分 类 号：V19[航空宇航科学与技术—人机与环境工程]