镍基高温合金大倾角气膜孔飞秒激光加工机理与工艺研究  

Research on Hole Wall Quality of High Angle Film Cooling by Femtosecond Laser on Nickel Base Superalloy

作　　者：肖强[1] 马国庆 靳龙平 Xiao Qiang;Ma Guoqing;Jin Longping(College of Mechanical and Electrical Engineering,Xi′an Technological University,Xi′an 710021,China;不详)

机构地区：[1]西安工业大学机电工程学院,西安市710021 [2]西北工业集团有限公司

出　　处：《工具技术》2022年第10期63-69,共7页Tool Engineering

基　　金：陕西省科技厅重点研发计划项目(2022GY-227);西安市科技计划-科技创新人才服务企业项目(2020KJRC0031);西安市未央区科技计划-产学研协同创新计划(201912);陕西省特种加工重点实验室开放基金(SXTZKFJJ201902)。

摘　　要：针对飞秒激光加工镍基高温合金叶片气膜孔时孔壁易出现沟槽的问题进行实验,研究了不同倾角对气膜孔孔壁的影响,发现倾角越大,孔壁越容易出现沟槽,当倾角为60°时,沟槽最深可达11.05μm,且沟槽只存在于入口下方处,其余位置并未发现沟槽。对飞秒激光能量密度分布进行数值计算,在距离焦点1mm,2mm和3mm处,光斑能量密度面积比镍基高温合金烧蚀阈值的面积分别高100%,76.1%和49.6%,证明了在叶片实际加工过程中激光的离焦加工较为明显。结合大倾角气膜孔孔口材料分布不均的实际情况,认为大倾角气膜孔孔壁出现沟槽的原因是飞秒激光离焦加工导致孔口下方向处加工过量,因此提出了一种涂层防护的方法来减少孔壁沟槽。经过实验验证,孔壁沟槽可以减少至2.54μm。In this paper,the problem of grooves in the hole wall during femtosecond laser machining of blade film holes is studied.The effect of different inclination angles on the wall of film holes is studied experimentally.It is found that with the increase of the inclination angle,the groove is more likely to appear on the hole wall.When the inclination angle is 60°,the groove depth could reach 11.05μm,and the groove only exists in the downward direction of the inlet,and the groove phenomenon is not found in other positions.The energy density distribution of femtosecond laser is calculated.The area of spot energy density higher than the ablation threshold of Ni base superalloy is 100%,76.1%and 49.6%at the defocusing points of 1mm,2mm and 3mm,respectively,which proves that the defocusing of laser is obvious in the actual process of blade machining.Combined with the uneven distribution of materials at the large angle gas film hole,the groove appears on the wall of the hole.The reason is that femtosecond laser defocusing leads to excessive processing in the direction below the orifice.A coating protection method is proposed to reduce the hole wall groove,which can be reduced to 2.54μm.

关 键 词：飞秒激光 烧蚀阈值 气膜孔 镍基高温合金 离焦加工 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TH162.1[机械工程—机械制造及自动化]