Modeling And Experimental Investigation On Machined Surface Features In Turning Supper Alloy

Superalloy has excellent mechanical properties, and is usually used formanufacturing the important parts of aircraft engine and industrial gasturbine. The machined surface quality of superalloy directly affectthe performance and service life of parts. Aiming at the characteristics thatsuperalloy is difficult to machine and lead to poor quality of surface, this thesisresearches surface features, carries out test analysis and modeling and simulation,providing theoretical support for optimizing of cutting parameters forsuperalloy. The specific research contents are as follows:First, the influence which is the cutting parameters such as cutting speed,feed rate, the amount of flank wear and lubrication to surface roughness ofsuperalloy is analyzed by cutting test; the machined surface defect types incutting process are analyzed and cutting surface geometry defects are observedby SEM.Secondly, the surface work hardening of superalloy is researched, and thereason of causing work hardening and influence factors are analyzed. Throughmeasuring microhardness and cutting test, the depth of hardening layer, thedistribution microhardness and work hardening rate were analyzed underdifferent cutting speeds, feed rate, tool wear, and lubrication ways.Thirdly, superalloy cutting experiment is carried out and the metallographicspecimen are prepared. The surface features are observed by SEM scanningelectron microscope, the organization structure of cutting surface white layer isanalyzed, the influence law of the cutting parameters on cutting temperature andthe thickness of white layer is analyzed, the surface white layer of superalloy isanalyzed by EDS spectrum analysis, the transformation mechanism of the whitelayer is proposed, which occurred in the formation of high temperature alloy.Finally, recrystallization form, nucleation mechanism and recrystallization form are analyzed in the superalloy deformation process. The microstructure inthe cutting process is analyzed by DEFORM-3D simulation software, the resultsshow that the situation of the temperature field and recrystallization percentagedistribution in the turning process of different parameters, and optimumprocessing parameters are got.