Elimination of the over cut from a repaired turbine blade tip post-machined by electrochemical machining
Elimination of the over cut from a repaired turbine blade tip post-machined by electrochemical machining
复制标题
通过电化学加工消除修复后的涡轮叶片尖端的过切
DOI：
10.1016/j.jmatprotec.2015.12.003
复制
发表时间：
2016-05-01
影响因子：
6.3
通讯作者：
Luo, T.
中科院分区：
文献类型：
--
作者：
Liu, W. D.;Ao, S. S.;Luo, T.
随着高强度淬火材料在涡轮叶片叶尖修复中的广泛应用，由于表面完整性差和刀具磨损严重，传统加工工艺正面临局限。电化学加工（ECM）为修复后的涡轮叶片叶尖加工提供了一种潜在的替代方法。然而，在使用传统刀具对修复后的涡轮叶片叶尖进行电化学加工时，经常会出现过切现象。为克服这一缺陷，本文提出一种基于余量分布的刀具解析修正方法。通过模拟分析工件表面的电流密度分布，并预测工件的形状演变。通过实验比较了使用常规刀具和修正刀具对工件形状的影响，以验证模拟结果。模拟和实验结果表明，修正刀具有助于消除电流密度峰值，从而避免过切。此外，通过实验研究了施加电压和加工时间对使用修正刀具加工涡轮叶片叶尖形状的影响。结果显示，使用修正刀具加工涡轮叶片叶尖的形状主要由加工时间决定。加工时间过长或过短分别会产生凹形或凸形，只有最佳时间才能产生可接受的形状。使用最佳参数重复实验表明，在批量修复作业中，使用修正刀具可以可靠地对涡轮叶片叶尖进行电化学加工，获得理想的形状和良好的表面质量。（C）2015爱思唯尔有限公司保留所有权利。
With the wide use of high-strength hardened materials in the repair of turbine blade tip, conventional machining processes are reaching limitations owing to poor surface integrity and high tool wear. Electrochemical machining (ECM) offers a potential alternative for the machining of repaired turbine blade tip. However, an over cut phenomenon often occurs in ECM of repaired turbine blade tip with a conventional tool. To overcome this drawback, this paper proposes an analytical tool correction based on the allowance distribution. Simulations were performed to analyze the current density distribution on the workpiece surface and to predict the shape evolution of workpiece. The effect of the use of conventional and corrected tools on workpiece shape was compared experimentally to verify the simulation. The simulation and experimental results illustrated that the corrected tool is helpful in removing the current density peaks and thus eliminating the over cut. Additionally, the effect of the applied voltage and machining time on the machined shape of turbine blade tip using the corrected tool were investigated experimentally. The results revealed that the machined shape of turbine blade tip using corrected tool is mainly determined by the machining time. A too long or too short machining time generates concave or convex shapes respectively, while only the optimum time produces an acceptable shape. Repeating the experiments with optimum parameters showed that turbine blade tip with desired shape and good surface quality can be reliably ECM machined using the corrected tool in batch repair operations. (C) 2015 Elsevier B.V. All rights reserved.