Identification Of FGH97 Superalloy Material Characteristic Parameters And Optimization Of Machining Parameters

Nickel-based powder superalloy has become a popular material in special equipment due to its excellent mechanical properties and high temperature oxidation resistance.It is the preferred material for key components such as aero-engine turbine disc,guide vane,marine gas turbine,and rocket engine.As a new nickel-based powder superalloy material,which independently developed by China,FGH97 has been applied in aero-engine and other application fields,showing good application prospects and economic benefits.At present,the mainly research in China is the powder molding process,microscopic properties and the influence of alloy elements on the mechanical and physical properties of FGH97.It is of practical significance to carry out the research on the static and dynamic mechanical properties and machining properties of FGH97 for its application and development.With the rapid improvement of electronic information technology,numerical simulation has become an important strategy for studying the mechanical properties,large deformation,and destruction of engineering materials.However,the dynamic constitutive relationship of materials has always constrained its development.The selection of material models and the setting of relevant parameters play a decisive role in the reliability and accuracy of numerical simulation.In this paper,based on the static and dynamic mechanical performance test of FGH97,the inverse identification method of computation is used to identify the material characteristic parameters of Johnson-Cook model of FGH97.Based on the identified model material characteristics,and combining FGH97 material cutting processing,the optimization of FGH97 material machining parameters is developed by using multi-objective genetic algorithm.The main contents of the research carried out and completed in this article are as follows:1.In order to obtain the mechanical properties of FGH97 material and provide corresponding input data and verification data for the identification of Johnson-Cook model characteristic parameters,the static compression test of FGH97 materials and the Split Hopkinson Pressure Bar(SHPB)test under room temperature and high temperature were carried out.Then the static and dynamic mechanical properties of the material and the deformation of the specimen are obtained,and the mechanical properties are studied and analyzed.2.In order to obtain a effective and accurate SHPB numerical model,the influence of grid cell division on the numerical model results in the modeling was studied,and the boundary conditions and related parameters were studied and analyzed.The incident and transmitted pulse waveforms were compared with the SHPB empty rod test.Finally,according to the SHPB system used in the experiment,a matching finite element model is established,and the deformation stress and simulation waveform of the specimen in the model are analyzed.3.In order to identify the parameters of the constitutive model,a reverse calculation method for quickly determining the characteristic parameters of the Johnson-Cook model of the FGH97 material was developed.First,analyze and establish a positive problem model for the material characteristic parameters.Then,perform parameter sensitivity analysis and directly solve the positive problem.Finally,use an intelligent optimization algorithm to solve the Johnson-Cook model characteristic parameters.The identification material characteristic parameters are substituted into the finite element model under different working conditions for solution,and compared with the tests under the corresponding working conditions to verify the accuracy of the recognition results.4.Based on the identified model material characteristic parameters,the FGH97 material turning finite element model is established.By comparing with the FGH97 cutting test under the same working conditions,the reliability and accuracy of the established numerical model are verified.Combined with the cutting model,a response surface model was constructed,and a multi-objective optimization model was established.The micro-genetic algorithm was used to optimize the processing parameters of FGH97.The results confirm that the optimized processing parameter set can make the processing efficiency and cutting force reach an ideal value,and can provide reference guidance for actual processing.