Study On Chip Shape And Surface Quality Of Turning Nickel Base Superalloy Under Spray Cooling

Nickel-based superalloy GH4169 is widely used in aerospace engine main parts because of its advantages such as good material structure stability and excellent mechanical properties.However,GH4169 has the problems of poor machining performance,large cutting force,difficult to break chips,easy to generate sawtooth chips,and poor surface processing quality in cutting processing.In view of these machining problems,this article uses a coated carbide tool to perform a turning test on a nickel-based superalloy GH4169 under the condition of spray cooling.The combination of theory and test is used to study the cutting force,the macroscopic shape of the chips,and The micro-morphology,the geometric characterization of the sawtooth chip,the surface roughness of the workpiece and the residual stress on the surface provide technical reference for improving the processing quality of nickelbased superalloy GH4169.The research is mainly carried out from the following aspects in this paper:Firstly,the effect of cutting parameters on cutting forces was studied.A singlefactor,four-level and three-factor orthogonal cutting parameter test scheme was adopted,and the coated GH4169 test was performed using a coated carbide tool under spray cooling.According to the results of orthogonal experiments,the influence of cutting parameters on cutting force was analyzed by means of range and variance.At the same time,an empirical model of cutting force of cutting parameters was established,and the goodness of fit and variance of prediction models were analyzed.Based on the results of the single factor test,the influence of cutting parameter on cutting force was explored.Secondly,the influence of cutting parameters on the macro-morphology and micro-morphology of chip was studied.The influence of cutting parameters on chip curl diameter was explored.The two theoretical systems of sawtooth chip generation were compared and analyzed,and chip samples were prepared to observe the microscopic morphology of the chip and measure the geometric characterization parameters of the sawtooth chip.Based on the adiabatic shear theory,the influence of cutting parameters on the microscopic morphology of chips was explored;the influence of cutting parameters on the geometric characteristics of sawtooth chips was analyzed.Then,the effects of cutting parameters and spray parameters on the surface roughness were studied.Based on the existing cutting parameter test schemes,a single factor test scheme of spray parameters has been added;and workpiece samples have been prepared for observing the surface morphology of the workpiece and measuring the residual stress on the workpiece surface.According to the results of orthogonal experiments,the influence of cutting parameters on the surface roughness was analyzed by means of range,variance,etc.At the same time,an empirical model of surface roughness of cutting parameters was established,and the goodness of fit and variance of the prediction model were analyzed analysis.Based on the results of the single factor test,the influence of cutting amount and spray parameters on the surface roughness was explored,and the three-dimensional topography of the workpiece specimen was observed.Finally,the influence of spray parameters on the surface residual stress was studied.The X-ray stress meter was used to detect the residual stress on the surface of the workpiece.The influence of different spray pressure and spray flow on the surface residual stress was analyzed by combining theory and experiment.