Cailiao Baohu (Aug 2024)
Effect of KH-560 and Glass Powder on the Thermal Protection Performance of Silicone Resin Coatings
Abstract
To further enhance the mechanical properties and service temperature of silicone resin coatings， the effects of the silane coupling agent KH-560 and low melting point glass powder on the thermal protection performance of silicone resin coatings were investigated.The elastic modulus， bonding strength， thermal expansion coefficient， ablation， thermal insulation and thermal shock properties of the coating were tested using a high-temperature solid material dynamic elastic property tester， a universal electronic tensile machine， an expansion meter and a gas thermal shock experimental system； The composition， surface micromorphology and elemental content of the coating were analyzed using infrared spectroscopy， emission scanning electron microscopy， and its attached energy spectrum analysis.Results showed that with increasing KH-560 content (0～3%)， the elastic modulus and adhesion strength of the silicone resin coatings were initially increased and then decreased.When 2.0%KH-560 was added，the maximum values for the elastic modulus and adhesion strength of the coatings were achieved at room temperature， reaching 24.10 GPa and 4.40 MPa， respectively.This was mainly attributed to the enhancement of bonding between the silicone resin and the metal substrate， as well as between the filler and the silicone resin facilitated by KH-560.The addition of 110%glass powder was found to effectively improve the thermal stability and thermal shock resistance of the silicone resin coatings at 800 ℃， due to the melting of glass powder，which filled the voids generated by the decomposition of silicone resin， thereby preventing further oxidation decomposition of the silicone resin.Additionally， silicone resin coatings with a glass powder content of 110%were observed to exhibit good thermal insulation and ablative properties.
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