锥度球头刀加工钛合金TC4表面粗糙度建模

Modeling the Surface Roughness for Machining Titanium Alloy TC4 with Taper Ball-end Cutter

高性能商用航空发动机大型复合材料风扇叶片高速旋转时存在分层开胶风险,需要在其前缘通过胶结工艺装配钛合金TC4前缘金属加强边予以保护,而胶结性能受到装配表面粗糙度影响较大。本文针对钛合金TC4前缘金属加强边内腔加工表面粗糙度,以主轴转速、每齿进给量和轴向切深为设计因子,分别开展4种细长锥度球头刀四轴铣削钛合金TC4试验,测试已加工表面粗糙度。基于测试的样本数据,分别针对4种细长锥度球头刀建立加工表面粗糙度的经验模型。结果表明,主轴转速增加,直径为5.0mm时,表面粗糙度大幅降低,直径为3.0mm时,表面粗糙度却有所增加;主轴转速、每齿进给量增加时,直径4.0mm、2.4mm的锥度球头刀加工的表面粗糙度没有较大变化。随着轴向切深增加,4种直径的刀具加工的表面粗糙度均大幅增加。

Large composite fan blades of high-performance commercial aero-engines are at risk of delamination and gluing during high-speed rotation.It is necessary to protect the leading edge of the blade by assembling a titanium alloy TC4 leading edge metal reinforcement edge through the gluing process.However,the performance of gluing is greatly affected by the roughness of the assembled surface.In this paper,for the machining surface roughness of the inner cavity of titanium alloy TC4 leading edge metal reinforcement edge,with spindle speed,feed per tooth and axial cutting depth as design factors,four experiments were conducted using slender tapered ball-end cutters to machine the titanium alloy TC4.The surface roughness of the machined samples was measured.Based on the collected data,empirical surface roughness models were established for the four types of slender tapered ball-end cutters.The results show that the spindle speed increases and the surface roughness decreases considerably at a diameter of 5.0mm.Conversely,the surface roughness increases for a diameter of 3.0mm.The surface roughness machined by the tapered ball end cutter with diameters of 4.0mm and 2.4mm did not change significantly when the spindle speed and feed per tooth increased.The surface roughness machined by all the four diameters of the cutters increased substantially with increase in axial depth of cut.