GH4169G整体叶盘阶梯铣削稳定性研究

为解决高强高温合金GH4169G整体叶盘叶片铣削加工不稳定问题,通过有限元分析的方法,分析了沿大径方向(叶片宽度)和轴向(叶身方向)两种逐层铣削方案对加工稳定性的影响,研究了阶梯铣削工艺和传统双面对称铣削工艺对整体叶盘叶片铣削稳定性的影响.结果表明:沿大径方向逐层加工时,其理论绝对稳定极限切削深度小于实际加工中可能的最大切削深度,主轴转速、切削深度等切削参数选择范围较小;而沿轴向逐层加工时,其理论绝对稳定极限切削深度大于实际加工中可能的最大切削深度.与传统双面对称铣削工艺相比,阶梯铣削工艺使整体叶盘叶片的刚度得到提高,相同载荷下叶片的最大变形量降低了60%,其前6阶模态频率均较高,加工过程更稳定,加工出的叶片能满足设计要求. 

Stability research on step milling of GH4169G blisk

Finite element analysis was applied to solve the problem of instability during milling blisk blade made of high strength superalloy GH4169G. Both methods of milling along the major diameter and axial direction were studied to analyze the machining stability. The effects of both the step milling and general symmetry milling on the machining stability were analyzed in the milling process of the blisk blade. Results show that the limit cutting depth in the stability lobe is less than the probable maximum cutting depth, the machining parameters such as the spindle speed and cutting depth can be chosen in a small range when the blade is cut by layers along the major diameter. The limit cutting depth in the stability lobe is larger than the probable maximum cutting depth when the blade is milled axially by layers. The rigidity of the blisk blade is improved by the step milling method. The maximum deformation of blade is 60% lower than that of the general symmetry milling in the same load. Compared with the general symmetry milling, the step milling method has the higher frequencies at the first six modes and the better stability, and the blades machined can meet the design requirements.