Experimental Study On The Performance Of Integrated Thermal Protection Materials Against Thermal Insulation And Reuse

The integrated thermal protection material is a new type of thermal protection material integrating high-efficiency heat insulation,dimensionality,light weight and reusability.It is also the most promising thermal insulation material in the current thermal protection system,but the overall material structure is more complicated,and there are few studies on its macroscopic and microstructural evolution and life prediction.In this paper,the internal and external two-layer structure of integrated materials,namely ceramic thermal insulation tile and anti-ablative ZrB₂-MoSi₂materials,were tested repeatedly to investigate the thermal insulation performance changes of materials,focusing on the internal and external effects under different heat loading times.The macro/microstructure evolution of two single-layer structural materials reveals the evolution mechanism,determines the thermal insulation performance evaluation variables and constructs a life prediction model to achieve life prediction of the integrated thermal protection material's anti-insulation performance.First of all,for the inner and outer two-layer structural materials of integrated thermal protection materials,namely ceramic thermal insulation tile and anti-ablative ZrB₂-MoSi₂ materials,the thermal insulation ability under repeated thermal loading is studied respectively,and the thermal insulation performance characterization parameters are proposed.Macroscopic characterization method;using numerical simulation method to determine a reasonable temperature measurement scheme for the inner layer ceramic thermal insulation tile;and designing a reasonable high temperature fixture according to the shape,mechanical properties and thermal properties of the outer layer material,ie,the ablation resistant ZrB₂-MoSi₂ material.The test loading conditions were designed for different service environments of two single-layer structural materials.The repeated hot-load environment simulation test was carried out by oxyacetylene injection method and quartz lamp array heating method respectively,and the macroscopic variation of materials under different heat loading times was analyzed.Secondly,the composition of the two-layer structure of the integrated material,namely the ceramic thermal insulation tile and the anti-ablative ZrB₂-MoSi₂ material under the repeated thermal loading,and the evolution of the microscopic structure were studied by means of SEM,XRD and Micro-CT.By observing and analyzing the microscopic morphology of the fiber,whether the fiber dispersion is good,and the crystal structure changes,the structural information of the material is obtained comprehensively,and the microstructure evolution law of the two single-layer structural materials is summarized.By analyzing the microstructure evolution result of the material,it reveals the intrinsic reasons for the evolution of materials such as Z-direction size,density,mass and so on.Finally,for the problem of repetitive performance life prediction of integrated thermal protection materials,the concept of thermal insulation efficiency is introduced to characterize the life characteristics of materials.The thermal insulation performance evaluation is selected through the internal and external two-layer structure macro/microstructure evolution laws.Variables;using Cubic polynomial and Logistic and Hill nonlinear fitting methods to construct the relationship between the thermal insulation efficiency of ceramic thermal insulation tiles and anti-ablative ZrB₂-MoSi₂ materials and the evaluation variables of thermal insulation properties,and obtain the integrated materials.The life prediction model of the layer structure is tested and verified,and the appropriate life prediction model is selected by error analysis.