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Ti6Al4V alloy is widely used in aerospace and biomedical applications due to its excellent mechanical and thermal properties, but its poor machinability makes it a difficult-to-cut material. Electrical Discharge Machining (EDM) offers an effective non-conventional machining approach for such materials, where tool electrode selection and process parameters critically influence performance. This study presents a comprehensive experimental investigation into the effect of three tool electrodes—graphite, copper, and brass—on the EDM performance of Ti6Al4V alloy. Key input parameters, including pulse-on time (T on ), pulse-off time (T off ), and current, were selected based on equipment limits and prior studies. Taguchi’s L9 orthogonal array was used for experimental design, and analysis of variance (ANOVA) was employed to determine the statistical significance of each factor. Output responses—material removal rate (MRR), tool wear rate (TWR), surface roughness (SR), and dimensional deviation (DD)—were measured and optimized using the Teaching–Learning-Based Optimization (TLBO) algorithm. Among the electrodes, graphite achieved the highest MRR (31.03 mm³/min), lowest TWR (0.4648 mm³/min), and minimal DD (101.76 μm), while brass produced the smoothest surface (SR = 3.19 μm). A collection of non-dominated responses was also found using Pareto optimal points. A minor adequate deviance was observed between the TLBO algorithm’s predicted and actual findings. Scanning electron microscopy (SEM) analysis was conducted to evaluate surface morphology. The qualitative SEM results confirmed fewer defects and better surface integrity for graphite electrodes. The findings validate TLBO as an effective tool for EDM process optimization and provide practical guidance for electrode selection in machining Ti6Al4V.

Compacted graphite iron (CGI) plays an important role in contemporary manufacturing of automobile engine, and coated tool is the best choice for milling of CGI. But studies about the estimation of the wear of coated tool are still rare and incomplete. As tool wear is the main factor that affects the quality of machined surface, in this study, we proposed an intelligent model-adaptive neuro fuzzy inference system (ANFIS) to estimate the tool wear, and ANFIS was learned by the improved particle swarm optimization (PSO) algorithm. As the PSO algorithm is easy to fall into the local minimum, the vibration and communication particle swarm optimization (VCPSO) algorithm was proposed by introducing the self-random vibration and inter-particle communication mechanisms. Besides that, to obtain the optimal combination of milling parameters, the multi-objective optimization based on minimum cutting power, surface roughness and maximum material removal rate (MRR) was studied using VCPSO algorithm. The experimental results showed that the ANFIS learned by VCPSO algorithm (ANFIS-VCPSO) has better performance for the estimation of tool wear compared with other intelligent models. The VCPSO algorithm was tested using Benchmark functions, and the results showed VCPSO algorithm has the global optimization ability. Meantime, the best combinations of milling parameters under different tool wear status were obtained through VCPSO algorithm. The proposed ANFIS-VCPSO model as a new intelligent model can be applied for real-time tool wear monitoring, which can improve the machining efficiency and prolong tool life. In order to meet the requirements of green and intelligent manufacturing, the best combination of milling parameters was also obtained in this work.

In this paper, with the aim of improving hydrogen storage efficiency, cerium vanadate/reduced graphene oxide (CeVO 4 /rGO) nanocomposite was synthesized through a one-step hydrothermal method due to its unique characteristics, including suitable electrochemical behavior, high specific surface area, and high porosity. In addition to controlling the growth of CeVO 4 nanoparticles, hydrazine reduces graphene oxide (GO) to reduced graphene oxide (rGO) and enables one-step synthesis. FESEM images showed that the rod-like CeVO 4 nanoparticles were dispersed on the graphene plates. According to the obtained storage results, with the addition of graphene, the synergistic effect between the layers has increased and, as a result, the hydrogen storage capacity has increased. The highest amount of electrochemical storage of hydrogen in the synthesized nanocomposite was about 5430 mAh/g, which is a significant result compared to other nanostructures used.

— In this work, an electrochemical sensor based on a poly threonine modified graphite-carbon nanotube paste electrode was developed for the investigation of tyrosine. The modification of the electrode was characterized by field emission scanning electron microscopy, cyclic voltammetry, and differential pulse voltammetry. The modified electrode shows many advantages such as simple preparation, good sensitivity, short response time, good stability and reproducibility. The developed electrode was highly selective because of the determination of tyrosine in the presence of the ascorbic acid and the uric acid. Under optimal conditions; the cyclic voltammetry provides a linear response with the concentration range from 2 × 10 –6 to 2.5 × 10 –5 M and 3 × 10 –5 to 1.2 × 10 –4 M with the limit of detection and limit of quantification values of 2.9 × 10 –7 and 9.6 × 10 –7 M. The developed sensor was employed for tyrosine detection in pharmaceutical sample, recoveries obtained were in a range of 99.0 to 102.80%.

Electrical discharge machining (EDM) is a rapidly evolving method in modern industry that manufactures highly complex components. The physical properties of a tool electrode material are significant factors in determining the effectiveness of the process, as well as the characteristics of the machined surfaces. The current trend of implementing graphite tool electrodes in manufacturing processes is observed. Innovative material engineering solutions enable graphite production with miniaturized grain size. However, the correlation between the graphite electrode grain size and the mechanism of the process removal in the EDM is a challenge for its widespread implementation in the industry. This research introduces a new method to evaluate the impact of the graphite electrode grain size and machining parameters on the material removal effectiveness, relative tool wear rate, and surface roughness (Ra) of Hastelloy C-22 following EDM with negative polarity. The study utilized new graphite materials with a grain size of 1 µm (POCO AF-5) and 10 µm (POCO EDM-180). An assessment of the impact of the EDM process parameters on the technological parameters and the development of the surface roughness was carried out. Electrical discharge machining with fine-grained graphite electrodes increases process efficiency and reduces tool wear. Graphite grains detached from the tool electrode affect the stability of electrical discharges and the efficiency of the process. Based on the experimental results, mathematical models were developed, enabling the prediction of machining effects to advance state-of-the-art manufacturing processes. The obtained mathematical models can be implemented in modern industrial EDM machines as guidelines for selecting adequate machining parameters depending on the desired process efficiency, tool wear rate, and surface roughness for advanced materials.

Modern industry is focused on looking for new and effective technologies to manufacture complex shapes from alloys based on nickel and chromium. One of the materials widely used in the chemical and aerospace industry is Hastelloy C-22. This material is difficult to machine by conventional methods, and in many cases, unconventional methods are used to manufacture it, such as electrical discharge machining (EDM). In the EDM process, the material is removed by electrical discharges between a workpiece and a tool electrode. The physical and mechanical properties of the tool electrodes have a direct impact on the process efficiency, machining accuracy, and surface roughness. Currently, there has been a significant increase in the use of graphite as a material for tool electrodes due to the low purchase cost of the raw material, good machinability, and high sublimation temperature. In this work, an experimental investigation of the influence of the grain size of the graphite tool electrode on material removal rate (MRR), tool wear rate (TWR), and surface roughness (Ra) of Hastelloy C-22 was carried out. Two POCO graphite tool electrodes with a grain size of 1 µm (AF-5) and 10 µm (S-180) were used. Based on the experimental studies, empirical models describing the influence of machining parameters on technological indicators and the condition of the surface texture were determined. The research indicates that graphite with a larger grain provides higher process efficiency with high relative wear of the tool electrode. The lowest surface roughness was obtained for graphite with a smaller grain size (AF-5). The analysis of the machining parameters proves that the discharge current and pulse duration are the main factors determining the MRR and Ra values for both AF-5 and S-180 graphite. The time interval is the dominant parameter with regard to the relative wear of the graphite electrode.

This study aims to determine the extent to which coating composition and workpiece properties impact machinability and tool selection when turning Compacted Graphite Iron (CGI) under extreme roughing conditions. Two CGI workpieces, differing in pearlite content and graphite nodularity, were machined at a cutting speed of 180 m/min, feed rate of 0.18 mm/rev, and depth of cut of 3 mm. To assess the impact of tool properties across a wide range of commercially available tools, four diverse multilayered cemented carbide tools were evaluated: Tool A and Tool B with a thin AlTiSiN PVD coating, Tool C with a thick Al2O3-TiCN CVD coating, and Tool D with a thin Al2O3-TiC PVD coating. The machinability of CGI and wear mechanisms were analyzed using pre-cutting characterization, in-process optical microscopy, and post-test SEM analysis. The results revealed that CGI microstructural variations only affected tool life for Tool A, with a 110% increase in tool life between machining CGI Grade B and Grade A, but that the effects were negligible for all other tools. Tool C had a 250% and 70% longer tool life compared to the next best performance (Tool A) for CGI Grade A and CGI Grade B, respectively. With its thick CVD-coating, Tool C consistently outperformed the others due to its superior protection of the flank face and cutting edge under high-stress conditions. The cutting-induced stresses played a more significant role in the tool wear process than minor differences in workpiece microstructure or tool properties, and a thick CVD coating was most effective in addressing the tool wear effects for the extreme roughing conditions. However, differences in tool life for Tool A showed that tool behavior cannot be predicted based on a single system parameter, even for extreme conditions. Instead, tool properties, workpiece properties, cutting conditions, and their interactions should be considered collectively to evaluate the extent that an individual parameter impacts machinability. This research demonstrates that a comprehensive approach such as this can allow for more effective tool selection and thus lead to significant cost savings and more efficient manufacturing operations.

Compacted graphite iron (CGI) is increasingly used in industrial production due to its excellent mechanical property, especially in the field of high-performance automotive engine manufacturing, and has become a substitute for gray cast iron (GCI). However, the hard-to-machine problem caused by its excellent physical properties was the main issue affecting the surface quality of the CGI workpiece. As a new type of tool, the wiper insert could effectively improve the surface quality. In order to develop a long lifespan and high-stability wiper insert tool for CGI milling, this study conducted a series of experiments, including tool design and simulation, coating preparation and testing, and tool cutting performance testing. In the optimization of simulation analysis of tool geometric parameters, it was found that the numerical value of curved cutting-edge radius had a more significant impact on the cutting performance of wiper insert. In the coating test, AlCrN-coated wiper insert C with a coating thickness of 2.84 µm had the best load bearing and fracture toughness performance in the coating mechanic test and had the best coating bonding performance in the scratch test. In the milling experiment with a cutting speed of 125.7 mm/min, a feed rate of 0.15 mm/r, and a cutting depth of 0.5 mm, the coated wiper insert C had the longest tool life and the best machined surface quality of the workpiece. Compared to other coated tools, the tool life was extended by at least 15.7%, and the effective cutting area was increased by 20%, which means it was the most suitable tool for machining CGI.

Compacted graphite iron (CGI) has become the most ideal material for automotive engine manufacturing owing to its excellent mechanical properties. However, tools are severely worn during processing, considerably shortening their lifespan. In this study, we prepared a series of cemented carbide-coated tools and evaluated their coating properties in cutting tests. Among all tested coatings, PVD coating made of AlCrN (AC) presented with the best surface integrity and mechanical properties, achieving the best comprehensive performance in the coating test. The AC-coated tool also exhibited the best cutting performance at a low speed of 120 m/min, corresponding to a 60% longer cutting life and the lowest workpiece surface roughness relative to other coated tools. In the cutting test at a high speed of 350 m/min, the CVD double-layer coated tool (MT) with a TiCN inner layer of and an Al2O3 outer layer had a 70% longer cutting life and the lowest workpiece surface roughness relative to other coated tools.

The development of low-carbon refractories is of great significance, but it is limited by the deteriorated properties that resulted from the decreased graphite content. Incorporating composite powders has proved to be effective in improving the properties of low-carbon refractories. The recent progress in the synthesis of composite powders including modified graphite, nanocarbon-containing composite powders, oxide/non-oxide and non-oxide composite powders and their applications in low-carbon refractories were reviewed, and the future development of composite powder technology was prospected.