φ0.05mm深孔钻削有限元分析及工艺研究

微细钻头用于加工铝合金上直径小于0.1 mm、深径比10的小孔,钻头的主要破坏形式为根部折断和端部崩刃。针对刃具根部折断,本文分析了钻孔偏心及交变载荷产生的机理,使用Ansys仿真钻头偏心与抗弯强度关系,取钻头使用安全系数3～5时,计算得出钻头允许偏心位移4.47～8.16μm。三维钻削与二维切削转化力学模型分析表明,刃口端部为切削受力强度薄弱点,要满足安全系数3～5,则每转进给量要小于0.155μm。切削试验表明,采用主轴转速25 000 r/min、进给量0.5 mm/min,可实现0.05 mm硬质合金钻头连续加工30个深径比为10的微孔,孔径尺寸精度±5μm。

Research on Process in 0.05 mm Micro-hole Cutting with Finite Element Method and Drilling Test

This paper shows the research on the micro-hole which is smaller than 0.1 mm with thickness-to-diameter ratio about 10 cutting process of aluminium alloy by finite element method and drilling test.By simulating the cutting tool displacement and tensile strength,the safety coefficient of the micro drilling tool is calculated;the mechanics model of three-dimension drilling to two-dimension cutting in the same coordination is established,also the affection of the main cutting parameter on the axial thrust force and cutting momentum of torque is discussed.Simulation result shows drilling deviation is the main reason that causes the force transposition,and the top on the tool edge is the minimum in cutting process.If 3 5 is set to be safety coefficient,the permissive cutting tool displacement is 4.47～8.16μm and is lower than 155μm/rev.Tests shows that 30 micro holes were drilled consecutive with 0.05 mm hard alloy tool when the rotation speed is 25 000 rpm and the feed 0.5 mm/min,the micro-hole with thickness-to-diameter ratio is about 10 and the dimension precision can reach ±5μm.