Experimental research on machinability of different electrode materials for SEAM of the nickel-based superalloy GH4169

Abstract

The short electric arc machining technology is a technical category of electrical machining in the special machining industry. It further improves machining efficiency (1.92 × 105 mm3/min) in comparison to other electrical machining. In short electric arc machining, the electrode materials directly affect the surface quality of the workpiece, electrode loss, and dimensional accuracy. Therefore, the selection of the electrode material is particularly important. Using the nickel-based superalloy GH4169 machining as the research object, the study aimed to improve the material removal rate, while reducing the electrode loss. The experimental research on the short electric arc machining properties (machining surface quality, inter-polar voltage and current waveform, electrode loss analysis, surface morphology, microstructure, chemical components analysis, etc.) of four types of tool electrode materials (graphite, copper, Q235, and aluminum) separated by two groups was conducted, in the first group: under the certain technological parameter, machining the GH4169 by four kinds of tool electrode materials respectively. In the second group, the influence of different tool electrode materials on the material removal rate was studied by using graphite and copper as the tool electrode materials under the different process parameters of discharge current, pulse time, pulse interval, and air pressure. The results show that the mechanical properties of the electrode materials differed due to the different thermal properties of the electrode materials under the same process parameters. Furthermore, the different physical properties of the electrode material caused different effects on the residual heat, resulting in differences in the material removal rate. Under most of the discharge conditions, MRR occupied a large proportion in the graphite electrode, and the relative mass loss of the electrode was about 16.7% of that of copper, providing a solid theoretical basis for the electrode selection of the short electric arc machining hard surface materials.

Experimental research on short electric arc milling machining based on the mechanical-fluid coupling effect

“…Arc machining has the advantages of high removal efficiency and continuous and stable discharge, which provides an efficient and feasible means for realizing the efficient machining of difficultto-cut materials. 11,12 In 2001, General Electric (GE) designed BlueArcä technology for the efficient cutting of superalloy materials widely used in aircraft engines and power turbines. Research institutions and scholars in China have put forward different arc processing methods in recent years, and the large amount of related research work conducted has greatly promoted the application of arc processing in the field of special processing.…”

“…Arc machining has the advantages of high removal efficiency and continuous and stable discharge, which provides an efficient and feasible means for realizing the efficient machining of difficult-to-cut materials. 11,12…”

Experimental study on high-efficiency DC short electric arc milling of titanium alloy Ti6Al4V

“…Liu et al (2020) studied the effect of electrode polarity on DC short arc milling of titanium alloys and found that electrode negative machining can yield a higher machining e ciency [14]. Li et al (2018) studied the in uence of different electrode materials on pulse short arc milling and found that graphite provides a lower electrode loss rate, whereas red copper provides better surface quality [15]. Chen et al…”

Machining performance of titanium alloy in short electric arc milling

“…It is an original innovative technology in China. 11,12 It uses the tangential slip between the tool and the workpiece electrode under the hydrodynamic force of the gas-liquid mixed working fluid to achieve arc drawing and arc breaking in SEAM. Ti-6Al-4V is a titanium alloy with a þ b dual-phase structure.…”