Research On Correlation Technique And Mechanism Of High-speed Cutting Ni-based Superalloy GH4169

GH4169is a kind of Ni-base superalloy which has Ni-Cr solid solution as matrix,Ni3Nb and Ni3(Al,Ti,Nb) as strengthening phase. Its stable tissue, great activationenergy and low detrimental phase contribute to its property of high strength, goodplasticity, antioxidation and good corrosion resistance. So it can work for a long timeunder high temperature and corrosive circumstances even the stress and strain changefrequently. It has been the indispensable material in aerospace, aviation and energyindustry etc. GH4169is one of the most difficult-to-cut materials, whose depth of cut isonly about0.1. The strong cutting force, high cutting temperature, severe phenomenonof work hardening, short life span of cutting tool and common cutting speed of10~15m/min greatly lower the processing efficiency. The low cutting speed is an urgentproblem to be solved in aerospace, aviation and energy industry which are enjoying fastdevelopment. So reserch on the correlation technique and mechanism of the high-speedcutting GH4169is of great significance both in theory and in practice.Firstly, after the summary of high speed cutting theories and techniques at homeand abroad, to reach the goal of high speed cutting, a test based on Salomon hypothesisis to be carried on. The cutting force, cutting temperature and the influencing factorsand regulations of surface quality (surface roughness, work hardening, residual stress)are to be researched through turning test, milling test and simulation on the system. Andthe method to improve the cooling lubrication effect during high speed cutting ofGH4169will also be studied.Secondly, the deformation feature and constitutive modeling of high speed cuttingGH4169under the influence of mechanical-thermo coupled strong stress field were tobe studied. In order to get the dynamical constitutive equation conformed to high-speedcutting GH4169, which is beyond mechanical testing. Meanwhile, improve the accuracyof FEM simulation of GH4169high speed cutting.Through the test of rapid tooldisengage during right angle cutting to obtain chip root on the basis of physical modelof two dimensions cutting. And during the research of high speed cutting, metal elasticand plastic deformation with high temperature, strong strain and great strain rate arenoticed. To probe the modeling method of material constitutive modeling on the basis ofright angle cutting test and build constitutive equation that can rightly explain themechanics feature of cutting difficult-to-cut materials with high speed. Then throughcomparing the result of FEM simulation of GH4169high speed cutting based on theequation with the test result to verify whether the modeling method is accurate orreliable.Thirdly, tough curl chips will be produced during most cuttings of GH4169. Through dynamical analysis and FEM simulation method, the elastic and plasticdynamic phenomenon under complicated conditions is studied while the chips arecurled. And through analyzing the force condition on the cross section of the chips, lawsof stress distribution are to be discovered.Lastly, mechanism of chips formation will be discussed via probing the chipfeature of cutting GH4169with high speed. Through micro-observing the chips fromturning test and chip roots from rapid tool disengage test, observing the features andlaws of the deformation and damage of materials in the first deforming zone with CCDobserving system and SEM，analyzing difficult-to-cut GH4169material with goodhardness, high strength and high toughness, showing the twice deformation(first in thefirst deforming zone and the second in the second deforming zone) and damage processon the influence of high temperature, great stress and high stress rate of high speedcutting, the mechanism of how chips are formed is revealed.