Papers by Keyword: Machining Efficiency

Abstract: This Reinforcement learning (RL) techniques are increasingly employed for optimal tool path planning in CNC machining to improve efficiency and reduce costs. Traditional RL algorithms, like Policy Iteration, encounter challenges due to the vast design parameter search space. This has led to the development of innovative approaches such as auto-tuner-based ordinal regression methods, offering accelerated parameter exploration and faster convergence towards optimal policies. Lin et al. present a systematic solution for complex cavity milling tool path generation using RL, demonstrating superior speed and quality compared to evolutionary computational techniques. The shift towards RL-based approaches signifies a paradigm change in tool path optimization, emphasizing its potential to enhance machining efficiency and accuracy. This paper compares various RL algorithms and approaches, showcasing their effectiveness in optimizing tool paths. Results indicate improvements in machining efficiency, accuracy, and operational costs through the integration of RL models into CNC systems. Overall, RL-based optimization offers competitive advantages, aiding stakeholders in making informed decisions for efficient CNC machining operations.

Abstract: The present contribution focuses on finishing operations in machining. Finishing operations belong to the most time-consuming and surface quality-critical machining tasks. High-quality tools are available nowadays for choosing optimal tool paths for finishing. Yet, the finishing options for general shaped surfaces are still severely limited. Although CAM systems can efficiently generate tool paths, none of them offers the combination of finishing tool paths, modern productive methods and adaptive tool paths. Increasing the productivity while maintaining dimensional accuracy and the quality of finished surfaces is the key point in finishing. One of the ways to improving productivity is the use of constant cutting speed. The aim of this article is to present experimental verification of these assumptions and demonstrate the impact on the quality of the finished surface

Abstract: Recent years, use of the strong alkali ion water produced by electrolyzing high purity water (RO water) with addition of a small amount of electrolyte (potassium carbonate) is becoming widely used as a substitutable cleaning liquid in place of organic solvent which is said to exert a bad influence on the environment. The authors have been conducting a research to apply this strong alkali ion water (pH12 or so) to a working fluid for material removal processing. This is to cope with various problems relating to the existing water-soluble working fluid such as coolant putridity and the associated deterioration of factory environments and increased disposal costs of working fluids as well as to improve machining efficiency and tool life. In this study, the authors would like to describe how the working fluid consisting of water-soluble lubricant diluted with the strong alkali ion water contributes to an improvement of the factory environment and verify experimentally that the said fluid could improve the tool life by 1.2 to several times. In addition, a factor contributing to the improvement of material removal characteristics has been found to be the fact that the friction resistance of the said fluid containing the strong alkali ion water is as low as 2/3~1/2 of that of the fluid diluted with the city water.

Abstract: It has been made clear that the EC-PCD composed of boron doped diamond particles improves the performance in the die sinking EDM and wire EDM in comparison with the existing standard PCD (S-PCD). However, the effect of the property improvement could not been evaluated quantitatively in the research reports in the past. Therefore, in this study, wire EDM cutting tests were conducted on the specimens of S-PCD and EC-PCD, in addition to the evaluation of cutting efficiency and cutting PCD surface, a detailed investigation of the cut surface properties of the PCD has been performed under the color 3D laser scanning microscope. In order to investigate effects of a grain size of the source diamond, EDM cutting experiments were conducted on the EC-PCD specimens of 4 different grain sizes. As a result, it was found that the cutting speed was higher in the case of EC-PCD than the case of S-PCD, e.g., by 20% and 40% respectively in the sample of 10μm and 25μm particle size. Also, in the case of the cut S-PCD surface, a groove due to the discharge is formed in the boundary of the tungsten carbide layer and the PCD layer. However, in the case of the cut EC-PCD surface, the groove did not appear in the boundary.

Abstract: The material removal in ultrasonic machining (USM) is based on brittle fracturing of workpiece materials. The properties and fracture behavior are different for varied materials, and they would have an influence on the machining performance of USM. The smoothed particle hydrodynamics (SPH) method was used to simulate the USM process for different workpiece materials. Three typical hard and brittle materials, i.e. silicon carbide (SiC), alumina (Al₂O₃), and glass will be used as the workpiece materials. Experiments are also conducted for comparing with the simulation results. Through this study, the material fracturing processes for different work materials are shown visually using the SPH method, which is very useful for USM study.

Abstract: In order to study the basic rule of diamond wire saw slicing SiCp-Al composites, the theoretical analysis and experiments were carried out. The influences of diamond wire saw slicing speed and workpiece feed speed on surface quality and machining efficiency were discussed. The analysis results show that the machined surface gets smoother when diamond wire saw slicing speed changes from 2m/s to 3.5m/s, but gets rougher when diamond wire saw slicing speed changes from 3.5m/s to 4m/s. And the surface gets rougher when workpiece feed speed changes from 0.5m/s to 1m/s.The machining efficiency gets higher when diamond wire saw slicing speed and workpiece feed speed increase. These results provide guidance for selecting reasonable parameters in future research.

Abstract: In orthogonal turn-milling process, both of the workpiece and the cutter rotate at the same time, which causes cutting depth and cutting thickness to change instantaneously. In this paper, a new 2D stability model of orthogonal turn-milling is established, in which the effect of variable cutting depth and cutting thickness is considered. The stability lobe diagrams are obtained by using Full-discretization Method. By analyzing the stability of orthogonal turn-milling, it is found that it is better than that of ordinary milling in same machining conditions. It means that in orthogonal turn-milling process deep cutting depth can be chosen and high machining efficiency can be obtained compared to that in ordinary milling process.

Abstract: It is an important factor that tool size affects the quality and efficiency of complex curved surface of CNC machining. This paper starts with analyzing the functional relationship between the tool size and the quality and efficiency of complex curved surface, gives the selection method of optimal minimum tool which can ensure the precision of machining curved surface, establishes optimal selecting algorithm of reasonable large size tool with the most high efficiency as the objective, and for the curved surface of complex geometric features, puts forward tool combination selection method with effective area ratio of tool machining as a reference. Application examples show: the optimal selecting strategy of tool size in this paper, under the premise of adequately ensuring the machining quality of complex curved surface, can effectively improve the whole machining efficiency.

Abstract: ELID for SiC which enables the improvement of surface quality is put forward. ELID grinding technology is new technology of ultra-precision grinding, and the oxide film is formed on grinding wheel by electrolytic in-process technology, thus the wheel is in-process dressed. SiC material removal mechanism and ELID grinding mechanism is analyzed, the character and condition of brittle to ductile transition of SiC and surface formation mechanism of ductile mode grinding of SiC are studied, the results show that ELID grinding can realize ductile grinding ,this will lower the surface damage and improve the machining efficiency.

Abstract: In order to know the processing properties of the Electrical Discharge Machining titanium alloy on gas dielectric. Firstly, this paper does comparing experiment of EDM in gas processing titanium alloy. The results indicate that electrode dissipation is low with equifrequence square wave, positive polarity and low supply voltage to machining titanium alloy when pulse width is narrow. Secondly, this paper has done the orthogonal experiment and the variance analysis of experimental results, Its result shows that pulse width and peak current have a great influence on the machining efficiency .