Experimental Study On Turning Process Performance And Parameter Optimization Of AerMet100 Steel

As an important technology in production and manufacturing of components,metal material cutting is playing an important role in aviation industry and material engineering.AerMet100 Ultra-high strength steel,as aviation difficult machining material,in the process of turning caused by cutting force-thermal coupling effect,cutting stress and other indicators on the process properties of materials,surface integrity and machining efficiency of a certain degree of influence.In view of the precision and safety of aviation manufacturing industry,parameter constraints should be set to optimize the process performance index to enhance the processing efficiency and improve surface quality.Therefore,in order to further analyze the machining mechanism and process performance of AerMet100 Ultra-high strength steel and optimize the machining parameters,the relevant researches on the material turning process were carried out in combination with mechanical model,simulation and experimental verification.The main research contents are as follows:Firstly,based on the metal cutting deformation principle,the deformation parameters and friction factors of two-dimensional orthogonal cutting theory were analyzed and studied,and the mechanical model was constructed according to the shear plane theory.By means of coordinate rotation transformation and multi-plane coordinate system,the theory was extended to three-dimensional oblique cutting,and the mechanical models of different reference systems were established on the front knife plane and shear plane.Then,the relevant theories of finite element simulation technology were expounded,the merits and selection criteria of various simulation models were discussed,and the implementation criteria of finite element technology were introduced.Based on AerMet100Ultra-high strength steel material custom constitutive model,AdvantEdge-FEM software was used for finite element simulation,and compared with the software model and the actual turning test to verify its accuracy.Furthermore,the cutting force was measured by simulation test,the deformation parameters and friction factors of two-dimensional cutting were calculated,and the prediction model of the relationship between cutting tool front angle anddeformation parameters was fitted.What's more,aiming at the machining parameters,AerMet100 steel was analyzed by turning test with cutting force and surface roughness which were the evaluation indexes of machining performance.The single factor and orthogonal design method were used to analyze the cutting force index,and the influence law of cutting parameters on the variation trend of cutting force was studied and the exponential empirical models were established.For the surface roughness index,the orthogonal design based on Taguchi method and the CCD response surface design were used for experimental comparison.According to different design methods,two kinds of prediction models were established and their merits were analyzed.Further analysis of the metallographic structure of the machined section showed that the deformation region appeared near the machined surface and the grain appeared distortion and extrusion phenomenon,and the deformation degree decreased with the increase of the machining surface depth.Finally,in order to achieve the goal of high efficiency and high quality of cutting,with the processing efficiency(represented as the maximum material removal rate)and surface quality(represented as surface roughness and surface morphology)as the optimization objectives,Taguchi method,genetic algorithm and response surface optimization method were respectively used to optimize by single target and multiple target for different parameter combinations and prediction models.The differences of constraint conditions,target quantity and optimization effect under different methods were compared and analyzed.The optimal parameter combination under each optimization method was studied and verified by experiments.