Abstract
Surface machined by high-speed wire electrical discharge machining (HS-WEDM) at super-high thickness (more than 1000 mm) cutting suffers from uneven surface, a major problem that has been investigated in this paper. According to the analysis, as wire frame span increases, the rigidity of the wire electrode decreases, and under the action of discharge explosive force, wire electrode vibration intensifies. As a result, the machining stability inevitably decreases. However, the core problem is whether there is enough working fluid in the slit to dampen and absorb the vibration of the wire electrode so as to ensure the positional stability of the wire electrode. To verify the above point of view: first, the wire guide and gravity take-up with bidirectional tension in the wire feeding system were installed to improve the positional accuracy of the wire electrode; second, to improve the flow of the working fluid into the slit, the slit width was increased by improving the working fluid and a medium carrier with a higher melting point and vaporization point can reduce the vaporization of the working fluid in the slit as much as possible. The experiment showed that the outlet flow of the improved working fluid is 56.72% higher than that of the original working fluid when cutting a 750-mm thick workpiece, which increases the damping and vibration absorption effect of the working fluid on the wire electrode in the long and narrow gap. After the above measures were implemented, super-high thickness cutting can be carried out continuously and steadily, the surface evenness was significantly improved, and the workpiece with a thickness of 2000 mm was cut successfully.
Highlights
Super-high-thickness machining has broad application prospects in nuclear energy, aerospace and other fields [1]. since the wire electrode is travelling at a high speed in high-speed wire electrical discharge machining (HS-WEDM), the working fluid can be attached to the wire electrode and the working fluid can be brought into the processing area, which can ensure inter-electrode cooling, chip removal, and deionization, and provide cutting capability of superhigh thickness workpieces [2]
The main purpose of this paper is to study the influence of different working fluids on the surface evenness by changing the working fluid of super-high thickness cutting, so as to improve the surface quality of superhigh thickness cutting workpieces, and further expand the application space of super-high thickness cutting in other applications
For super-high thickness WEDM, the rigidity of the wire electrode decreases sharply due to the increasing length of the wire electrode in the processing area, so the vibration of the wire electrode greatly increases when it is slightly disturbed, and the working fluid is difficult to enter into the depth of the cutting slit, which leads to the greater difference between the interelectrode discharge state and the conventional thickness cutting
Summary
Super-high-thickness machining has broad application prospects in nuclear energy, aerospace and other fields [1]. since the wire electrode is travelling at a high speed in high-speed wire electrical discharge machining (HS-WEDM), the working fluid can be attached to the wire electrode and the working fluid can be brought into the processing area, which can ensure inter-electrode cooling, chip removal, and deionization, and provide cutting capability of superhigh thickness workpieces (more than 1000 mm) [2]. Since the wire electrode is travelling at a high speed in high-speed wire electrical discharge machining (HS-WEDM), the working fluid can be attached to the wire electrode and the working fluid can be brought into the processing area, which can ensure inter-electrode cooling, chip removal, and deionization, and provide cutting capability of superhigh thickness workpieces (more than 1000 mm) [2]. In 2017, Li et al [5] conducted theoretical analysis and experimental verification on the inter-electrode discharge energy and working medium flow in super-high thickness cutting, realized some important conditions for super-high thickness, and achieved cutting of a 1500 mm thick workpiece. Ensuring surface evenness of super-high thickness workpiece cutting is still a significant challenge. Improved surface evenness for super-high thickness cutting workpieces is an important developmental direction to expand the application scope of HS-WEDM machine tools [1]. The uneven stripes appear on the workpiece surface after super-high thickness processing, which seriously damages the surface quality of the workpiece, and greatly limits the applicability of
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
