基于弹性基体磨具的3D打印高温合金叶片磨抛试验  

Grinding and Polishing Test of 3D-printed Superalloy Blade Based on Elastic-matrix Abrasive Tool

作　　者：郭磊 王家庆[1] 明子航 郭万金 马臻 靳淇超[1] GUO Lei;WANG Jia-qing;MING Zi-hang;GUO Wan-jin;MA Zhen;JIN Qi-chao(School of Construction Machinery,Chang'an University,Xi'an 710064,China;State Key Laboratory of Mechanical Transmissions,Chongqing University,Chongqing 400044,China;Xi'an Institute of Optics and Precision Mechanics of CAS,Xi'an 710119,China)

机构地区：[1]长安大学工程机械学院,西安710064 [2]重庆大学机械传动国家重点实验室,重庆400044 [3]中国科学院西安光学精密机械研究所,西安710119

出　　处：《表面技术》2023年第2期43-54,共12页Surface Technology

基　　金：国家自然科学基金(51805044);陕西省自然科学基础研究计划(2022JM–254);中国博士后科学基金(2020M673318);机械传动国家重点实验室开放基金(SKLMT–MSKFKT–202006)。

摘　　要：目的验证弹性基体磨具自适应磨削抛光加工增材制造镍基高温合金叶片的工艺可行性。方法以硅橡胶基体磨具弹性磨抛技术为基础,建立弹性磨具与叶片接触的有限元模型,分析磨具与工件接触区域内应力和材料去除分布。以有限元分析结果为指导,研究磨具接触变形和材料去除对轨迹规划的影响,确定合理的轨迹步长和间距,并通过控制工件位姿角的变化,保证在磨抛过程中磨具与工件的接触状态不变。以GH4169镍基合金叶片为加工对象,采用硅橡胶弹性固结磨料磨具在小型四轴加工平台上进行磨抛试验。结果仿真结果表明,弹性磨具与曲面工件之间的接触区域为椭圆形,应力和材料去除分布都由椭圆心到周围逐渐减小;当弹性磨具的压缩量为3 mm时,基于弹性接触有限元分析结果确定的最优轨迹间距为9 mm。试验结果表明,采用自适应磨抛轨迹抛光后,叶片表面无明显划痕和抛光纹理,表面粗糙度Ra由开始的1.846μm降至0.182μm,标准差由0.108μm降至0.026μm,材料去除率为3.432×10^(9)μm^(3)/min。结论硅橡胶弹性固结磨料磨具可用于GH4169镍基合金叶片的超精密磨抛,基于弹性磨具接触区域应力分布及工件位姿变换提出的自适应轨迹规划能够保证叶片磨抛区域表面质量的一致性。Shape-Adaptive Polishing(SAP)is an effective method for the polishing of hard and brittle materials.The work aims to verify the feasibility of the adaptive grinding and polishing of 3D-printed nickel-based superalloy engine blades with elastic matrix abrasive tools.Firstly,a finite element model of the elastic contact between the polishing tool and the blade was established based on the elastic grinding and polishing techniques with silicon rubber-based abrasive tools.In addition,the stress distribution and material removal function within the contact area were analyzed.Furthermore,the effect of contact deformation and material removal of abrasive tools on trajectory planning was studied according to the finite element analysis.Finally,the reasonable trajectory step size and spacing were determined,where the contact state between the grinding tool and the workpiece was kept unchanged during the grinding and polishing process.The experimental tests were carried out on a desktop CNC machining system.EOSM2903D printer was employed to fabricate the blade,and the GH4169 nickel-based alloy was selected as the source material.The preparation of the abrasive tool was realized by a molding process,where the Smooth-On Ecoflex 0050 silicon rubber and micron-sized diamond grains were selected as the binder matrix material and abrasives.During the experiment,the rotation axis of the silicon rubber-based abrasive tool was consistently vertical to the blade surface by controlling the position and orientation of the blade.The simulation results showed the elliptical contact area between the elastic tool and the curved surface workpiece.Also,the stress distribution and material removal rate decreased gradually from the ellipse’s center to the periphery.The optimal track spacing determined was 9 mm when the compression of the elastic abrasive tool was 3 mm.The optimal track spacing increased with the increasing compression of the elastic abrasive tool.The polished blade surface topography was observed through the optical microsc

关 键 词：自适应磨削 柔性抛光 镍基高温合金 轨迹规划 表面质量 

分 类 号：TG58[金属学及工艺—金属切削加工及机床]