Research On Tool-chip Friction Characteristics And Tool Wear Of GH4169 Under High-pressure Cooling

GH4169 superalloy has excellent physical and mechanical properties and microstructure,and can work under extreme conditions,such as high temperature oxidation and severe corrosion.Therefore,it is mainly used to manufacture thermal components,such as aero engines and various turbine rotors.Due to the GH4169 superalloy is a typical difficult-to-cut material,during the cutting process,the intense friction between the tool and chip will lead to strong thermoplastic deformation of the workpiece,so it will have a serious impact on the cutting force,chip deformation,tool life and surface quality of the workpiece.High-pressure cooling cutting is a new type of cooling method,compared with conventional cooling cutting method,highpressure cooling can not only effectively reduce the cutting temperature,but also improve the characteristics of chip breaking during processing.Therefore,in view of the complexity and importance of machining GH4169 superalloy workpiece,this paper conducts an in-depth study on cutting GH4169 tool-chip friction characteristics and tool wear under high-pressure cooling,mainly including the following aspects:Firstly,combining the theoretical knowledge of mechanics and metal cutting principles,a analysis of the injection characteristics of high-pressure coolant is carried out,and the relationship equation between the injection diameter,flow rate and injection pressure of coolant is obtained;based on the analysis of boundary lubrication mechanism,the force synthesis and decomposition methods are used to carry out an analysis of the forces on the contact area between the tool-chip under high-pressure cooling,and the characteristic parameters related to the high-pressure coolant injection are established Based on the flow trajectory of the chip on the front tool surface,the analytical model of the tool-chip contact length is established,and the chip curling and fracture model under high-pressure cooling is established by combining the impact of high-pressure coolant on the chip,which provides some theoretical basis for the later high-pressure cooling cutting test research and simulation analysis.Secondly,through Third Wave Advant Edge simulation analysis,the tool-chip contact length,chip curl radius,cutting force and tool stress change law under different injection characteristics parameters are simulated,and the preliminary prediction of the possible areas of tool wear under high-pressure cooling is made,laying a certain theoretical foundation for tool wear research.Finally,the high-pressure cooling cutting experiment was conducted for GH4169 alloy material,and the cutting force test data were collected by KISTLER force measuring instrument,and the trend of changes in cutting force and chip morphology by each injection characteristic parameter was analyzed,and the established theoretical model was verified by combining with the simulation analysis results;based on the high-pressure cooling cutting test,an in-depth analysis was made on the cutting of GH4169 under high-pressure cooling.Based on the highpressure cooling test,the wear types and mechanisms of PCBN tools during the cutting of GH4169 under high-pressure cooling were analyzed,and the microscopic morphology of the tools were observed by EDS spectroscopy and SEM,and the wear forms of the tools under different injection pressures were analyzed.It provides certain solution ideas for tool design for high quality machining of superalloys under high pressure cooling.