Research On Efficient Steady-State Milling And Machined Surface Integrity Of GH4169 Large Pitch Trapezoidal Thread

Thread structures are widely used in connecting fasteners and transmission components of mechanical equipment.With the widespread application of nickel based high-temperature alloys and high machining requirements for difficult to machine materials,research on the surface integrity of efficient steady-state milling combined with machining of nickel based alloy threads has become increasingly important.During the milling process,directly selecting a regular thread milling cutter for one-time forming processing can cause over cutting of the thread,resulting in incomplete tooth shapes.Additionally,due to the large contact area between the tool and the workpiece,greater cutting force is generated.Tool parameters and cutting parameters are two important factors that affect the variation of cutting force,and also affect the variation of residual stress in surface integrity.The magnitude of cutting force determines the smoothness of the machining process,while residual stress affects the performance of the workpiece.Therefore,when machining difficult to machine materials,it is necessary to carefully study the tool parameters and milling parameters.On the basis of analyzing the machining requirements of nickel based alloy large pitch trapezoidal threads,this article selects appropriate tool types and materials,develops a reasonable milling plan,and designs the tool tooth profile.Based on UG and VERICUT,simulation processing is conducted to verify whether the tool design is reasonable and whether the milling plan is feasible.Establish a finite element model for thread milling based on ABAQUS,and conduct single factor and orthogonal experiments on the influence of tool geometric parameters on cutting force.Based on this,further study the influence of milling parameters on cutting force,in order to obtain the tool parameters and milling amount under the minimum cutting force.Finally,the influence of tool geometry parameters and milling parameters on residual stress is studied,and the optimal combination of tool parameters and milling parameters is determined by combining the minimum cutting force and residual stress.Using the designed tool and selecting the optimal parameter combination,milling experiments were conducted on nickel based high-temperature alloy GH4169.The actual processed thread profile was complete and the accuracy met the requirements.The research results of the project have important guiding significance for the analysis and selection of tool parameters and process parameter schemes for efficient steady-state milling of nickel based high-temperature alloy large pitch trapezoidal threads,combined with cutting forces and residual stresses.