As a main difficult problem encountered in electrochemical machining (ECM), the cathode design is tackled, at present, with various numerical analysis methods such as finite difference, finite element and boundary element methods. Among them, the finite element method presents more flexibility to deal with the irregularly shaped workpieces. However, it is very difficult to ensure the convergence of finite element numerical approach. This paper proposes an accurate model and a finite element numerical approach of cathode design based on the potential distribution in inter-electrode gap. In order to ensure the convergence of finite element numerical approach and increase the accuracy in cathode design, the cathode shape should be iterated to eliminate the design errors in computational process. Several experiments are conducted to verify the machining accuracy of the designed cathode. The experimental results have proven perfect convergence and good computing accuracy of the proposed finite element numerical approach by the high surface quality and dimensional accuracy of the machined blades
1 December 2023 in The International Journal of Advanced Manufacturing Technology
The flow field distribution in an interelectrode gap is one of the important factors that affect the machining accuracy and surface quality in the electrochemical machining (ECM) process for aircraft blades. In the ECM process, some process parameters, e.g., machining clearance, processing voltage, and solution concentration, may result in electrolyte fluid field to be complex and unstable, which makes it very difficult to predict and control the machining accuracy of ECM. Therefore, 30 sets of experiments for cooling hole making in ECM were carried out, and furthermore, the machining accuracy and stability of cooling hole were concentrated. In addition, the flow channel of the geometrical model of the gap flow field was established and analyzed according to the electrolyte flow state simulation by CFD. The effects of the flow velocity mode on the machining accuracy and stability for cooling hole making were investigated and determined in detail.
316L stainless steel (316L SS) exhibits excellent corrosion resistance, mechanical properties, and biocompatibility, but the rapid melting and solidification of the laser powder bed fusion (PBF-LB/M) process reduce the properties of the newly formed parts. This study aims to enhance the mechanical properties of PBF-LB/M PBF-LB/M-formed 316L SS parts by investigating the effects of various heat treatment temperatures. The results show that an appropriate heat treatment temperature can improve the microstructure and mechanical properties of the formed parts. Lower temperatures have minimal effects on performance; however, at 1100 °C, recrystallization occurs, resulting in more uniform grain structures, improved densification, and substantial stress relief. The residual stress is reduced by 85.59% compared to the untreated PBF-LB/M samples, while the ferrite content is significantly decreased, making the phase structure more homogeneous. Although both yield strength and tensile strength decrease, plasticity improves by 21.11%.