High-speed Wire Research Articles

Enhancing high-speed EDM performance of hybrid aluminium matrix composite by genetic algorithm integrated neural network optimization

Hybrid aluminium matrix composites (HAMCs) are highly valued in manufacturing sectors but are difficult to machine conventionally due to reinforcements' inherent hardness and abrasiveness. This research finds high-speed wire electric discharge machining (WEDM) to be a potent solution for machining stir-squeeze-casted HAMC (AA2024 with ceramic nanoparticles: Al2O3, SiC, Si3N4, BN) and creating complex profiles with superior erosion characteristics. The erosion performance has been assessed in terms of material removal rate (MRR) for different profiles (plane, angular, and curve), and wire wear ratio (WWR) by employing machining variables, i.e., pulse voltage (PV), pulse current (PI), wire feed rate (WFR), pulse (P), and drum speed (DS). Results revealed that MRR_curve has highest MRR (37.84 mm3/min), followed by MRR_angular (36.07 mm3/min) and MRR_plane (34.40 mm3/min). The lowest WWR (0.0094%) was achieved at lower magnitudes of machining variables. The microscopic observations unveil shallow craters, minute-sized melt redeposits, and micro-pores on machined surface under the conditions of PV = 90 V, PI = 2 A, WFR = 13 m/min, P = 20 mu, and DS = 40 Hz. Optimization using non-dominated-sorting-genetic algorithm (NSGA-II) resulted in significant enhancements of 75.37, 73.90, and 76.01% in MRR_plane, MRR_angular, and MRR_curve, respectively, and a depreciation of 16.50% in WWR.

Upgrade and Renovation of Steel Billet Scale in front of High-speed Wire Furnace

This article briefly introduces the weighing device for steel billets in front of the heating furnace of the high-speed wire rod unit, and analyzes and summarizes the problems existing in the original weighing device for steel billets in production and use. Based on on-site installation conditions, design a new weighing method, match a large range weighing sensor, upgrade the automation control of the weighing device, and remotely transmit the billet weighing data to the MES system of the group. The automatic, stable, reliable, and accurate measurement of steel billet raw materials has been achieved, providing important guarantees for the accurate measurement of production line billet and product yield.

Partial Cross Mapping Based on Sparse Variable Selection for Direct Fault Root Cause Diagnosis for Industrial Processes.

Root cause diagnosis of process industry is of significance to ensure safe production and improve production efficiency. Conventional contribution plot methods have challenges in root cause diagnosis due to the smearing effect. Other traditional root cause diagnosis methods, such as Granger causality (GC) and transfer entropy, have unsatisfactory performance in root cause diagnosis for complex industrial processes due to the existence of indirect causality. In this work, a regularization and partial cross mapping (PCM)-based root cause diagnosis framework is proposed for efficient direct causality inference and fault propagation path tracing. First, generalized Lasso-based variable selection is performed. The Hotelling T2 statistic is formulated and the Lasso-based fault reconstruction is applied to select candidate root cause variables. Second, the root cause is diagnosed through the PCM and the propagation path is drawn out according to the diagnosis result. The proposed framework is studied in four cases to verify its rationality and effectiveness, including a numerical example, the Tennessee Eastman benchmark process, the wastewater treatment process (WWTP), and the decarburization process of high-speed wire rod spring steel.

Study on discharge characteristics and process of multi-channel high-speed wire electrical discharge machining for metal workpieces

Study on discharge characteristics and process of multi-channel high-speed wire electrical discharge machining for metal workpieces

Expert Experience and Data-Driven Based Hybrid Fault Diagnosis for High-Speed Wire Rod Finishing Mills

Expert Experience and Data-Driven Based Hybrid Fault Diagnosis for High-Speed Wire Rod Finishing Mills

Enhancing Cutting Rates in Multi-Channel HSWEDM of Metal Materials with a Novel Decoupling Circuit.

Multi-channel high-speed wire electrical discharge machining (HSWEDM) has shown great potential in enhancing the cutting rate of metal workpieces. However, the mechanism of multi-channel discharges in this technique remains unclear. In this paper, the equivalent circuit and processing model of the multi-channel HSWEDM were developed to investigate the discharge characteristics. It was found that the equipotential between electrodes is the primary factor causing electrical signal coupling between channels, hindering the achievement of synchronous discharge. To address this issue, a novel power supply with a decoupling circuit was devised. By utilizing the combined effect of electrode wire resistance and current limiting resistance (Rc), a potential difference was induced between electrodes in different channels, enabling electrical signal decoupling and facilitating synchronous discharge. The impact of Rc on synchronous discharge was examined, revealing that a reduction in Rc can increase the gap voltage of non-breakdown channels, thereby enhancing the discharge ratio. Finally, cutting rate experiments were conducted. When the new power supply was used for electrical signal decoupling, the cutting rates of multi-channel WEDM were significantly improved. Compared to single-channel HSWEDM, the cutting rates of two-channel and four-channel HSWEDM are enhanced by 84.06% and 247.83%, respectively.

Effect of interpulse voltage on recast layer machined by HSWEDM

ABSTRACT To improve the cutting speed and reduce burned layer caused by the accumulation of discharge products during high energy high-speed wire electrical discharge machining (HSWEDM), it is necessary to further study the discharge characteristics. Based on not changing the original high-frequency pulse power supply and servo feed system, an interpulse voltage power supply module is designed to improve the electrolysis effect. Comparative results show that under the same experimental conditions, the interpulse voltage can improve machining stability and cutting speed during high-energy rough cutting. The thickness of the recast layer can be reduced by 37.1%. The recast layer can be greatly reduced by the rough cutting and trimming process. The interpulse voltage has a major influence on the finishing process. The thickness of the recast layer can be further reduced from 16.65 μm to 6.23 μm by optimizing the order of interpulse voltage applied to the process.

Effect of multi-channel discharge distribution on surface homogeneity in super-high-thickness WEDM

The multi-channel discharge phenomenon for super-high-thickness (more than 1000 mm) cutting is studied in high-speed wire electrical discharge machining (HS-WEDM). In super-high-thickness cutting, the length of the wire electrode with a poor conductor is longer in the machining area, so the resistance of wire electrode cannot be ignored. It is found that the main reason for the formation of multi-channel discharge is that there is a high voltage between electrodes after dielectric breakdown due to the resistance characteristics of the wire electrode. When the conventional discharge circuit is used for machining, the voltage between electrodes in the middle of the workpiece is much higher than that at the upper and lower ends, which is easier to generate multi-channel discharge. Multi-channel discharge has the characteristic of dispersing discharge energy, which results in inhomogeneous surface roughness on the whole section of the workpiece. To improve the distribution characteristics of the inter-electrode voltage after dielectric breakdown, a novel discharge circuit is proposed, which gradually increases the inter-electrode voltage of discharge points distributed along the thickness direction of the workpiece, and significantly improves the formation probability of multi-channel discharge on the whole cutting surface. A super-high-thickness workpiece with a thickness of 1000 mm is used for continuous cutting. The cutting speed of the two types of discharge circuit is basically the same. But the surface roughness machined by the rear-end parallel circuit is reduced by 15.8%, and the surface homogeneity is greatly improved.

Dynamic and static strain aging of steel during high-speed wire drawing

This article presents the analytical studies results on the effect of high-speed drawing technological parameters on the temperature and deformation conditions of the wire. The temperature increase of the wire during drawing in a monolithic die is the sum of the strain heating and heating caused by sliding friction on the “die–metal” surface. In the course of the research, it was found that the strain heating of the wire does not exceed 50 °C. An increase in the drawing speed from 10 to 40 m/s leads to an increase in deformation heating by 2–4 °C. The heating of the wire due to contact sliding friction, depending on the technological parameters of drawing, can reach 320 °C, while the proportion of metal heated to a temperature above 150 °C does not exceed 5%. The degree of influence of the friction coefficient on the heating of the wire is shown. The average strain rates under the conditions of modern high-speed drawing reach 7000 s‒1. The research results demonstrated that the maximum strain rate during drawing in monolithic dies can exceed twice the average strain rate. Increasing the drawing speed from 10 to 40 m/s leads to an increase in the strain rate up to 5 times. In the course of the research it was established that there are absence of conditions for the occurrence of dynamic strain aging due to impurity atoms of carbon, nitrogen and oxygen was established. At the same time the temperature-rate parameters of high-speed wire drawing creates conditions for the beginning of dynamic deformation aging of steel in the presence of hydrogen atoms. Therefore, during heat treatment and pickling, it is necessary to exclude the hydrogenation of steel. It has been established that in order to exclude static deformation aging of steel during drawing, it is necessary to prevent heating of the wire above 180‒200 °C.

Simulation Analysis and Optimal Design of Spinning Head Dynamic Balance

The laying head is an important equipment in a high-speed wire rod production line. The dynamic imbalance of the spinning head will cause the laying head to vibrate greatly during operation, which will seriously affect the spinning quality and the life of the laying head. In order to make the dynamic balance of the laying head meet the requirements, the critical rotational speed of the laying head rotor is firstly analyzed by using ANSYS software, and it is concluded that the laying head rotor is a rigid rotor. Then, the double-sided dynamic balance simulation of the spinning head was carried out using ADAMS software, and the correction masses required by the spinning head on the two calibration surfaces were obtained. The counterweight structures are designed according to the dynamic balance simulation results, and the thicknesses of the counterweight structures are optimized. The dynamic unbalance masses M1 and M2 of the optimized spinning head in the two calibration planes are reduced from 1.2456kg and 3.7855kg before optimization to 3.9133e-6kg and 2.9954e-6kg, and the eccentricity is reduced from 0.9966mm to 0.0002236mm, meet the design requirements.

Mathematical Modeling of Heating and Strain Aging of Steel during High-Speed Wire Drawing

In this article, a mathematical model of the wire’s average temperature change in the process of multiple drawing on high-speed straight-line drawing machines has been developed. The calculation results showed that the average temperature of the wire during a drawing at a speed of up to 45 m/s on straight-line drawing machines could reach 400 °C. Deformation heating of the wire during drawing does not exceed 60 °C, and heating due to sliding friction can reach 300 °C, depending on the friction coefficient, which ranges from 0.05 to 0.15. The average strain rates under the conditions of the modern high-speed drawing process reach 7000 s−1. Over the course of the research, it was found that there are no conditions for the occurrence of dynamic deformation aging due to impurity atoms of carbon, nitrogen and oxygen. At the same time, at the temperature and speed parameters of the high-speed wire drawing, conditions are created for the onset of the dynamic strain aging of steel in the presence of hydrogen atoms. Therefore, during heat treatment and pickling, it is necessary to exclude the hydrogenation of steel. It has been established that in order to exclude static strain aging of steel during drawing, it is necessary to prevent heating the wire above 180–200 °C.

Automatic Optical Inspection System for Wire Color Sequence Detection.

Given the huge demand for wire in today’s society, the quality of the wire is especially required. To control the quality of the produced wire, the industry has a great desire for automated optical inspection technology. This technology is a high-speed and highly accurate optical image inspection system that uses mechanical sensing equipment to replace the human eye as the inspection method and simulates manual operation by means of a robotic arm. In this paper, a high-performance algorithm for the automated optical inspection of wire color sequence is proposed. This paper focuses on the design of a high-speed wire color sequence detection that can automatically adapt to different kinds of wires and recognition situations, such as a single wire with only one color, and one or two wires covered with aluminum foil. To be further able to successfully inspect even if the wire is short in the screen and the two wires are close to each other, we calculate the horizontal gradient of the wires by edge detection and morphological calculation and identify the types and color sequences of the wires in the screen by a series of discriminative mechanisms. Experimental results show that this method can achieve good accuracy while maintaining a good computation speed.

Control design of a reciprocating high-speed wire feed system for 7-axis robotic electric discharge machining

For decades, researchers have struggled to solve 6-axis robotic vibration while machining hard-to-cut materials. On the other hand, wire electric discharge machining (WEDM) stands out as a non-conventional machining process able to cut large and complex profiles of any conductive hard-to-cut material with minor non-contact forces. Thus, WEDM is a promising process to be combined into a robot to overcome vibration and low accuracy. However, the robot characteristics of a high degree of freedom combined with payload limitation oblige to separate the heavy wire winding system from the robot end-effector, demanding an equally high degree of freedom and unconventional solutions to feed and control the wire electrode. This study designs and reports experimental findings of the first robotic WEDM apparatus based on a high-speed winding system with 600 m of wire length, capable of controlling the wire speed from 1 to 10 m/s and wire tension from 0.1 to 10 N. The system adopts flexible outer cases to travel and reciprocate the wire into a 7-axis robotic system composed of a 6-axis robot and an external rotating axis. The proposed design is a highly dynamic process whose wire tension and speed are achieved by a hybrid controller to cope with the non-linear relation of speed and tension provided by the magnetic clutch. It combines a regression open-loop control for optimality and wire breakage avoidance with a closed-loop control to guarantee admissibility while coping with wire friction disturbances. The findings review a novel wire winding system capable of controlling usual wire disturbance and stepped surface of reciprocating high-speed WEDM as well as additional friction and elastic behaviour of the flexible case, delivering wire tension of ± 12% along with stable EDM process and uniform surface roughness between wire reciprocation areas with a Ra of 2.94 μm. Potential adoption of the method can finally make 6-axis robots a feasible and advantageous technique compared to computer numeric control (CNC) while shaping monolithic and complex workpieces of conductive and hard-to-cut materials.

ANALYSIS OF PARAMETERS AND MODELING OF WEAR ROLLS OF HIGH-SPEED WIRE BLOCKS

Research on the study of features and modeling of wear of rolls remains relevant, due to the need to predict the stability of rolls and determine their costs. The importance of such research increases with the introduction of new roll materials, in particular tungsten carbide alloys.
 The processes of hot rolling are characterized by the simultaneous action of several main mechanisms of wear. Various models for predicting wear are known for these mechanisms, but under current conditions there is a need to develop local models that take into account the peculiarities of technology. Such conditions include high-speed wire blocks.
 The aim of this work is to analyze the parameters of high-speed rolling according to the level of their impact on the wear of the rolls and to develop a model of wear of the rolls of the unit based on the actual wear of several sets of rolls. For the analysis the results of measurements of wear of four sets of rolls which were executed by an optical method and calculated parameters of rolling on usual technology are used. Correlation analysis was performed, using the indicator of wear intensity, as the ratio of maximum wear to the amount of rolled metal in the caliber. A linear dependence was chosen to build the regression model.
 According to the results of the analysis of the wear rate and rolling parameters in the high-speed wire block, it is established that the well-known tribological rolling parameters vary according to the block modules in a rather narrow range, which does not reveal their effect on wear. That is, the effect of these parameters is approximately the same for all modules of the unit, so it is not statistically confirmed.
 The correlation analysis revealed the most significant parameters of rolling by the effect on the wear rate, namely the relative velocity of the cell, the elongation coefficient and the cell shape parameter. For these parameters, a regression model was obtained to determine the wear rate. The model confirms the adequacy and provides an acceptable level of accuracy in determining the wear of the rolls of the block.
 The obtained regression model can be used to determine the durability grooves rolls of the block and predict the expense of rolls, as well as to adjust the technological parameters to reduce wear and expense of rolls.

Design criteria study and simulation for underactuated symmetric pinching mechanism of pinch roll machine in high-speed wire rod product line

Inspired by the underactuated robotic hand mechanism and its feature of shape adaptive and compliant envelop grasping, the paper presents an underactuated symmetric pinch mechanism to solve the problem of pinch rollers idle and slipped or pinched too tightly. Pinch roll machine is a key device in the high-speed wire rod product line. It is usually designed with actuated symmetric pinch mechanism. The paper considered the pinching and conveying condition of linear objects and discussed the possibility of the underactuated symmetric pinch mechanism to be applied in the pinch roll machine for the first time. Three kinds of underactuated symmetric pinch mechanism solutions are presented. A displacement can be generated at the underactuated joint when the symmetric synchronous pinch action is implemented. The spring system can buff the instantaneous clamping force to reduce the dynamic impact of clamping force. Suitable design criteria are deduced from statics and kinematics analysis. In the process of pinching and conveying wire rods, the contact force is required to be kept at a constant value when the size of wire rods changes. Thus, it can protect the rod from being damaged while pinching and conveying and it can avoid the fatigue damage caused by excessive pinching impact force. Then, the pinching and conveying conditions of four different kinds of variable diameter wire rods are analyzed through 3D modeling and motion simulation experiments. Simulation results show that the proposed underactuated pinching and conveying mechanism can satisfy shape adaptive pinching and conveying irregular long-shaped wire rods. The research method is novel and feasible. The design result will be beneficial to improve the service life of the pinch roll machine.

Servo control for super-high-thickness cutting in high-speed wire electrical discharge machining

Servo control for super-high-thickness cutting in high-speed wire electrical discharge machining

A large-area single-filament infrared emitter and its application in a spectroscopic ethanol gas sensing system

Nondispersive infrared (NDIR) spectroscopy is an important technology for highly accurate and maintenance-free sensing of gases, such as ethanol and carbon dioxide. However, NDIR spectroscopy systems are currently too expensive, e.g., for consumer and automotive applications, as the infrared (IR) emitter is a critical but costly component of these systems. Here, we report on a low-cost large-area IR emitter featuring a broadband emission spectrum suitable for small NDIR gas spectroscopy systems. The infrared emitter utilizes Joule heating of a Kanthal (FeCrAl) filament that is integrated in the base substrate using an automated high-speed wire bonding process, enabling simple and rapid formation of a long meander-shaped filament. We describe the critical infrared emitter characteristics, including the effective infrared emission spectrum, thermal frequency response, and power consumption. Finally, we integrate the emitter into a handheld breath alcohol analyzer and show its operation in both laboratory and real-world settings, thereby demonstrating the potential of the emitter for future low-cost optical gas sensor applications.

Study on controlled rolling and cooling process of CH1T steel High speed wire 1# shaoguan steel

Under the background that the high-grade industrial wire rod such as cold heading steel is mainly developed in the first line of Shaoguan Iron and Steel Co., Ltd., the controlled rolling and controlled cooling process of ultra-low carbon cold heading steel ch1t is studied in this paper. A large number of high-temperature tensile tests for CH1T are carried out on Gleeble 3800 thermal simulation testing machine, and the high-temperature plastic characteristics of CH1T and stress-strain curves at different temperatures are obtained, At the same time, the transformation points Ac1, Ac3, Ar1 and Ar3 of ch1t steel and the dynamic CCT curve were measured, and the process improvement measures were formulated on the basis of experimental research. The field practice shows that the proposed process improvement measures have greatly improved the problem of low yield of ch1t cold heading steel in the first high line of Shaoguan Iron and Steel Co., and achieved remarkable economic benefits.

Facile Fabrication of Durable Superhydrophobic Aluminum Alloy Surfaces by HS-WEDM and Chemical Modification

Durable superhydrophobic aluminum alloy surfaces were prepared through a facile method: combining high-speed wire electrical discharge machining and chemical modification. Three types of pulse width were selected to machine the aluminum alloy surfaces with different levels of surface roughness. The effect of immersion time in perfluorooctanoic acid on the wettability of the aluminum alloy surfaces was examined. The contact angle of the superhydrophobic aluminum alloy surfaces was [Formula: see text], and the sliding angle was [Formula: see text]. After sanding with coarse sandpaper, the aluminum alloy surfaces still exhibited superhydrophobicity with a stroke of 450[Formula: see text]cm, indicating good mechanical durability. The prepared superhydrophobic aluminum alloy surface heated for 2[Formula: see text]h within the 190–240∘C temperature range showed favorable thermal stability. In addition, the superhydrophobic aluminum alloy surface exhibited self-cleaning property. Therefore, the superhydrophobic aluminum alloy surface prepared by using the simple mass production method showed good mechanical stability, thermal stability, and self-cleaning property, as well as broad application potential.

Study on surface evenness of super-high-thickness cutting in high-speed wire electrical discharge machining

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.