Preparation And Performance Of Thermal Shock Resistance Composite Materials

Rocket launchers and gun barrels in the aerospace and military fields will be subjected to thermal loads such as heat flow impact and ablation damage during operation.In order to ensure the normal use of materials,this paper conducts research from two aspects of improving the thermal protection performance and mechanical properties of composite materials:apply phenolic resin and silicone rubber with excellent ablation resistance to composite materials,study the influence of the mixing of phenolic-based composite material layer and epoxy-based composite material layer,the application of silicone rubber film on the thermal shock resistance;in terms of improving the mechanical properties of the material,focusing on the fiber winding molding process,the influence of the addition of 0°shaft yarn,multi-directional multi-angle winding,and symmetrical layer mode winding on the mechanical properties of the composite winding bobbin is studied.The specific work is as follows:First,the curing kinetics and rheological properties of phenolic resin,epoxy resin,and phenolic/epoxy blended resin were studied.Through non-isothermal DSC test,the characteristic temperature,curing activation energy,reaction order of the resin were obtained,combined with the actual situation to determine the curing temperature of the resin and correct the curing system when preparing the composite material in the later period;test the resin viscosity to obtain the change rule of viscosity,temperature and time,and determine the temperature and time required for the resin to reach the pre-gel state.Prepare for the subsequent preparation of composite laminates and winding bobbins.According to the design scheme,nine types of composite laminates are obtained through a molding process and a hot-pressed silicone rubber film,and then wet winding process is used to prepare five types of composite material winding bobbins.Study the thermal shock resistance of 9 kinds of composite laminates,divide each laminate into two parts,one of them is subjected to heat flow shock treatment,after the heat flow shock,collect the temperature of the back of the sample,observe the microscopic morphology of the sample.Subsequently,the compression test and the bending test were performed on the two parts of the sample,and the results showed that:the pure epoxy-based composite had the most severe damage to the micro-morphology.The compressive strength and modulus,flexural strength and modulus attenuation rate are all above 40%,respectively.The hybrid composite material of the matrix composite layer has better thermal shock resistance than pure epoxy-based composite materials,and the microscopic morphology is not significantly damaged.The compressive strength and modulus,flexural strength and modulus he decay rate properties,i.e.better flow heat shock resistance.It can be seen that adding a phen rate are both below 30%,and with phenolic as the thickness of the matrix composite layer increases,the decay rate of compressive and flexural properties gradually decreases,but the increase of the phenolic matrix composite layer means that the epoxy composite layer decreases,and the overall mechanical properties of the material will decrease.The hybrid composite with a ratio of 1:1;has the best overall performance after heat flow impact;the composite with silicon rubber membrane has the best heat flow resistance.The microscopic appearance is almost not damaged.The compressive strength and modulus,flexural strength and modulus decay rate are all around 10%,and the larger the film thickness of the silicone rubber,the lower the decay rate properties,i.e.better flow heat shock resistance.It can be seen that adding a phenolic-based composite material layer and a silicone rubber protective film to the material can greatly improve the thermal protection performance of the material.Subsequently,the interlayer shear test was conducted on the hybrid laminate,and the results showed that the interlayer performance of the hybrid sample was good.However,the use of epoxy film at the intersection of the two resin-based materials can better improve the interlayer performance of the material.The axial compression test of the composite material winding tube showed that:the addition of 0°shaft yarn,multi-directional multi-angle winding,and symmetric layering mode winding can improve the axial compression performance of the composite material winding tube,and the symmetric layering the mode winding includes two winding designs including 0°shaft yarn and multi-directional multi-angle winding,which has the most obvious effect on improving the axial compression performance of the winding tube.