Analysis Of Thermal Shock Resistance Of Novel High Temperature Resistant Ceramic-based Composite Parts

Severe aerodynamic heat can cause extreme thermal stress on objects moving at high speeds,which in turn can damage the structure of the object.The necessary thermal protection measures are required,and usually thermal protection coating is a good protection measure.Ceramic-based composite coatings have many advantages such as light weight,high temperature resistance,thermal shock resistance,etc.It is a key component to solve the problem of aerodynamic heating in the aerospace field and has important application prospects and strategic significance,so it is widely concerned.The following experimental and numerical simulation studies have been carried out for a new type of iron particle-reinforced phase alumina ceramic-based composite member with attention to its thermal shock resistance in the face of high Mach number aerodynamic thermal environment conditions.The thermo-physical properties of the new iron particle-reinforced phase alumina ceramic-based composite coating are considered to have a direct impact on its hightemperature resistance properties,but it is difficult to obtain the material parameters accurately from non-standard composite samples,and thus the numerical simulation prediction method of its thermo-physical properties is investigated.The method of representative volume cell is used to establish the numerical simulation model of particle reinforced random distribution,followed by obtaining the thermal physical parameters of the new composite coating material with temperature,then theoretically analyzing the change law of the performance parameters of the new composite coating material,and finally revealing the influence of thermal physical parameters such as elastic modulus on the thermal shock resistance performance.In order to study further the high-temperature resistance characteristics of iron particlereinforced phase alumina ceramic-based composite coated members under severe aerodynamic thermal conditions,a numerical simulation research method is used to establish numerical simulation models of new composite members of airfoil and flat plate types.The evolution of temperature and stress fields of new composite members has been revealed in the case of high Mach number,and then the influence of local high temperature and severe stress gradients on the thermal shock resistance of new composite members has been analyzed.On the basis of theoretical analysis,improvement methods are investigated to enhance reliability.From the perspective of improving the coating stress distribution,design basis is proposed for the wing member fixing method and the new composite coating thickness.The thermal response of the member corresponding to different material parameters is investigated,and finally the volume share of iron particles favorable for stress reduction is derived.Considering the unknown service performance of the new composite member,the thermal shock resistance of the new composite member under severe aerodynamic thermal conditions is explored,and the effects of the surface morphology,pre-set cracks and coating thickness of the new composite coating on the thermal shock resistance performance are experimentally analyzed by means of water quenching to derive the coating-like characteristics in the case of non-flaking of the coating.The validity of the numerical simulation model is verified concerning,among other things,the effect of the location of the coating cracks and the coating thickness on thermal damage.