Tool Edge Research Articles

A Novel Method for Improving the Skiving Accuracy of Gears with Profile and Lead Modifications

Skiving is an efficient gear cutting technology with relatively high machining accuracy, especially for internal gears. Nevertheless, the machining accuracy can hardly be satisfied if the skived gear is modified, so we try to extend the definition and hypotheses domain of the previous works. In this paper, fundamental research is conducted to further improve the skiving accuracy. Firstly, a new type of skiving tool with double rake faces is proposed for flexibly meeting different modification requirements of the two flanks of the work gear teeth. Secondly, the mathematical model of curve-surface conjugated cutting edges of the skiving tool for enveloping the tooth flanks of the working gear with profile modification is established. Then, the algorithm of the skiving tool path with alterable shaft angle in the cutting process is proposed for eliminating the twist of gear tooth flanks with lead modification. Finally, machining simulations are carried out to verify the feasibility of the proposed improved skiving methods.

Modelling and Analysis of Areca Nut Collecting Machine

Areca is a prominent commercial crop in coastal regions of Karnataka, a state of India. Major difficulties faced by areca growers include the shortage of labor and intensive time required for collecting areca nuts from ground during the drying process. To address the above problem, an area collecting machine is modelled. For design optimization of machine components, stress analysis on chassis, impact analysis on feeder ramp and deflection analysis on conveyor belt are assessed using solid edge tool. Design modifications incorporated from the above Finite Element based analysis are increasing the thickness of feeder ramp from 3 mm to 6mm along with the provision of ribs and providing support plates for conveyor belt. Modelled machine can bear 100 kg load with bagging efficiency of 900 areca nuts for per revolution of the belt.

Comparison of penetrated MnS grains by steel matrix in variously loaded free-cutting steels with/without Pb as one of the workability parameters

The free-cutting steel is one of the essential structural steels in electrical appliance industry and automotive industry. Most of the steel contains Pb, as solid lubricant, chip breaker, tool edge stabilizer and tool life extender. MnS grains also play the same role of Pb. However, Pb is toxic so that it will be prohibited to add to the steel in near future. Steel industry has tried to replace Pb with other element(s) and/or compound(s). The trials are still going on. This study proposes a candidate of the workability parameters for free-cutting steels with/without Pb. Investigated steels were loaded quasi-statically (strain rate: 1×10-3 s-1) and dynamically (1×103 s-1) up to fracture. Half of the specimens were pre-fatigued to form easier slip situation in steel matrix. After fracture, thin steel matrix penetrated into plenty of MnS grains. For the steel with Pb, the ratios of the number of such penetrations to those of total grains maintained almost the same value for all loading conditions. The ratios were varied with the loading conditions for the steel without Pb. These facts meant that Pb was a key element for easier slip of steel matrix. Therefore, this ratio had a feasibility to be one of the workability parameters for the free-cutting steel.

A Novel 2D Micromilling FEM simulation strategy to optimize the flow stress law of IN625

The products miniaturization tendency of the last years led to an acceleration of micromilling process development. Considering the high-quality requirements, a deep knowledge of this operation, concerning ploughing-shearing transition, tool run-out, and tool edge radius effects, is mandatory, especially when machining difficult-to-cut materials. For this reason, this paper introduces a novel 2D micromachining Finite Element Method simulation strategy for micromilling forces evaluation, when cutting IN625. The major output of this technique consists in the computation of an optimized flow stress law, suitable for the simulation of high-speed machining. Particle Swarm Optimization method was employed for optimizing the flow stress parameters by comparing the cutting force predicted by an analytical model previously calibrated on experimental data, providing good agreement. This strategy permits the micromilling process predictive analysis, avoiding costly optimization experimental tests.

Numerical study on the impacts of tool edge geometry and cutting conditions in orthogonal machining of AISI 1045 steel

Numerical study on the impacts of tool edge geometry and cutting conditions in orthogonal machining of AISI 1045 steel

Effect of friction properties of TiN and CrN coated tool edges on cutting ability of austenitic spheroidal graphite cast Iron containing 35% Nickel

Effect of friction properties of TiN and CrN coated tool edges on cutting ability of austenitic spheroidal graphite cast Iron containing 35% Nickel

Совершенствование технологии производства кукурузы на зерно в условиях Приамурья

The yield of corn grain depends on the tillage methods used in the cultivation technology of wide-row crops. To make comprehensive assessment of the use of various combinations of the cultivator’s working tools, the authors carried out a two-year study to improve the technology of growing corn for grain by optimizing the system of mechanized cultivation of wide-row crops. The essence of optimization is to change the combination of working tools in a combined tillage unit and change the width of their arrangement along the row spacing width and the depth of soil cultivation. Integrated deep tillage contributes to the destruction of weeds from a larger area between the rows and provides optimal conditions for the growth and development of corn. In 2021, use was made of a tillage unit with a combination of working tools - two one-side flat cutting shares (edges) with overlapping of the working tool edge and a V-shaped share in the center of the inter-row spacing. This combination resulted in a corn yield of 3.62 t/ha. Compared to other types of tillage, the increase was from 0.61 to 1.10 t/ha. This year, in comparison with 2022, in the early phases of the growth of corn and the development of its reproductive parts from April to May, excessive moisture was observed, while in June and July the moisture level was insufficient. In 2022, the use of two universal V-shaped shares with overlapping the working tool edge, inserting wheel spiders in the center of inter-row spacing ensured a yield of 9.15 t/ha. Compared to other types of tillage, the increase was from 0.33 to 1.99 t/ha. The provision of a high yield level in 2022 was facilitated by excessive moisture in the period from April to June and the accumulation of moisture in the soil. The choice of a combination of working tools should be determined by weather conditions.

Numerical study on the impacts of tool edge geometry and cutting conditions in orthogonal machining of AISI 1045 steel

Numerical study on the impacts of tool edge geometry and cutting conditions in orthogonal machining of AISI 1045 steel

Predviđanje hrapavosti površine tankih delovi sa zidovima na koje utiču varijacije radijalne dubine rezanja tokom perifernog procesa glodanja

During the peripheral milling process, great transverse displacement vibrations of the thin-walled part are occurred under the acting of milling tool edge forcesdue to their low dynamic rigidity and the radial depth of cut ae variations. In this work, the main surface roughness parameters are evaluated for stable milling process conditions through maximum radial displacements determined by a theoretical method and a finite element (FE) computation utilizing numerical simulations. The cutting tooth edge forces are calculated along the effective part for each tooth tool engaged into part material in discrete spatial and time steps using flat-end mills. Finally, the radial displacements are confronted, which are close in magnitude and in profile shape trend. Therefore, the generated cutting tooth edge forces showed gradual stabilities while changing the parameter ae from 05 mm to 0.75 mm, respectively. Then, the parameters Ra and Rq contribute more to these stabilities than Rv.

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The Vinci Power Nap® neurotechnological system created for energy naps, which can benefits mankind on Earth and in space travels. This cutting edge tool helping to reduce stress, jet lag, regulating the circadian rhythm, improving focus, efficiency, reaction times, preventing losing bone mass, the quality of sleep, health and human wellbeing in future smart cities and Lunar, Martian habitats. The remarkable results can be found in studies on UN Delegates at COP24, UNICEF project for war traumatized refugees women and children, soldiers with PTSD, pilots and analog astronauts, showing the healing power of touching, frequency of rocking, napping in a zero gravity position. Good sleep is needed to reset, recover, strengthen the immune system, also avoid errors resulting from fatigue and jet lag, which is especially important for business leaders, doctors, drivers, athletes, students, soldiers, pilots, astronauts and tourists. The frequency of the VPN technology pendulum movement is a revolution in the synchronization of breathing, heartbeat, delta waves in the brain, during which the best regeneration of the body and mind occurs. Moreover, the pulsating pressure on the skin increase the level of hormones: dopamine, oxytocin, serotonin, etc. All this contributes to the regeneration of sleep and energy, improving human’s psychophysical condition, longevity and advances in sleep and space medicine.

Döküm Yöntemi ile Manganlı Çelik Malzemeden Üretilen Abkant Pres Zımba ve Dişi Kalıpların İşlenebilirlik Yönünden İncelenmesi

Punches and dies employed in sheet metal “V” bending have been obtained generally from stock materials, AISI 4140 and EN C45 (Ck 45), in industrial applications through machining. The fact that local and different manufacturing methods have been applied in manufacturing these punches and dies has gained great significance in terms of external dependency and economy. The purpose of this study is to manufacture punches and dies used in “V” bending process from manganese steel via cast method and compare the newly obtained molds with presently used molds in terms of machinability and surface roughness. In this study, the experimental samples from both AISI 4140 and manganese steel were machined at different cutting parameters (cutting speed, feed rate, cutting depth), hence they were compared by analyzing with regard to chip morphology, cutting tool edge wear and surface roughness. At the end of the study, it was concluded that the punches and dies manufactured from manganese steel produced in foundry and widely found are alternatives compared to available AISI 4140 steel molds in terms of machinability.

The origin of the trough retouch in the Lublin-Volhynian culture

The technique of trough retouch played a key role in the Lublin-Volhynia culture as the most expressive technology of co-shaping the edges of flint tools. An important role is played by the so-called retouched blade-daggers, produced using this retouching technique. They werepart of the equipment for the graves of men considered to be members of the local elite.They appeared in a similar context only in the early Eneolithic Skelya culture in the Black Sea steppes and are dated from at least 4500 to 4100 BC. Specimens from the steppes must have been a source and act as a model for imitation in the production of analogous artefacts in the latter culture. The lack of retouched blade-daggers in Trypillia and Malice culture proves that the Lublin-Volhynia culture population took them directly from the Skelya culture. This adaptation took place no later than 4100 BC, when the Lublin-Volhynia culture population already had their own elite, ready to use retouched blade-daggers.

Maltese chert: An archaeological perspective on raw material and lithic technology in the central Mediterranean

The Maltese Islands in the central Mediterranean are renowned for their prehistoric archaeological record, particularly the megalithic ‘temples’ and associated ceramics and artwork. The temples were built by a society lacking metal technology, who relied on stone and organic materials. Knapped stone tool (lithic) technology, to produce sharp edged tools for tasks like cutting, hide working, and wood shaping offers insights into human behaviour in Malta, as well as into themes of exchange and connectivity. As well as imported chert and obsidian, local chert was widely used to make stone tools in prehistoric Malta. The local chert has generally been described as low-quality, yet relatively little research has been conducted on its distribution, characteristics, and use. In this paper I report a survey of chert sources, identifying a wider distribution of chert outcrops along the west coast of Malta than previously discussed. Some general macroscopic properties are outlined, as well as aspects of variability in the chert sources. Knapping experiments were then conducted on samples of chert collected, allowing clarification of its characteristics. These observations are used to offer some insights into lithic technology in Neolithic and Temple Period Malta, such as the hypothesis that the high frequencies of multidirectional flake production and subsequent ‘scraper retouch’ reflect adaptations to the characteristics of local chert.

복셀 기반 NC 밀링가공 절삭력 고속 시뮬레이션

With the advent of the 4th industrial revolution, advanced digital manufacturing technologies are actively developed to strengthen manufacturing competitiveness. Smart factories require a real-time digital twin including a Cyber-Physical System (CPS) of machines and processes and intelligent technologies based on the CPS. To predict machining quality and optimize machines and processes, it is necessary to analyze the cutting force during machining. Therefore, for real-time digital twin, a fast cutting force simulation model that receives information such as the positions of the feed axes in short time intervals from the CNC and calculates the cutting force until the next information is input is required. This paper proposes a voxel-based fast cutting force simulation in NC milling for real-time digital twin. The proposed simulation model quickly calculates the cutting force by using only information of voxel elements removed by each tool edge without complicated Cutter-Workpiece Engagement (CWE) and chip thickness calculations in previous studies. To verify the performance of the developed simulation, experimental machining was performed and the measured cutting force and simulated cutting force were compared. It was demonstrated that the proposed model can successfully predict the cutting force 3.5 times faster than the actual process.

Shaping of the Fresnel lens array on roller molds by 6-axis diamond machining

The Fresnel lens arrays are rapidly developing with the increasing demand for better optical performances and capabilities. For the roll-to-roll embossing of optical films, direct diamond machining of the Fresnel lenses on roller molds has been realized by installing an additional goniometer on the 5-axis ultra-precision machine tool in the previous study. However, this method owns two shortcomings, i.e., the communication delay between the machine tool and the goniometer and the poor positioning accuracy of the goniometer. In this paper, a 6-axis diamond shaping method is proposed to fabricate the Fresnel lens array on the roller periphery by utilizing a commercial 6-axis ultra-precision machine tool. It is ensured that the side cutting edge of the diamond tool matches the Fresnel lenses profiles during shaping. Also, the tool rake face is always perpendicular to both the roller tangent plane at the cutter location point and the cutting velocity relative to the roller via the synchronized rotations of the A-, B- and C-axes to avoid the tool–workpiece interference. The process to calibrate installation errors is introduced and utilized. The tool path is generated according to the cutting tool geometry, the lens parameters and the machine tool configuration. Experiments are carried out by machining the designed Fresnel lens array on a roller mold, which consists of lenses with different feature heights. The surface qualities of the lens arrays are evaluated and the influence of the block time to run the CNC code are also analyzed. The experimental results verify that the proposed method is effective and flexible for machining of the Fresnel lens array on roller molds.

The influence of cut material on the slicing efficiency effects of stone tool flake size, edge length, and gross edge curvature

Cutting actions were likely an important factor in the emergence and evolution of stone tools. In recent years, experiments have shown many factors can influence the efficiency of cutting behaviors, including tool form, tool material, and tool-user. Here, following other researchers, we test whether the material getting cut influences the efficiency effects of particular variables, namely flake size, cutting-edge length, and gross-edge curvature. Slicing six different materials, five participants used 300 stone flakes with quantitatively documented differences in flake size, cutting-edge length, and gross-edge curvature. The results of our Generalized Linear Mixed Models (GLMM) provide evidence that specimen size, edge length, and edge curvature have differential effects based on the material being cut.Our results support the hypothesis that the hominin need or desire to process particular materials potentially influenced the production and selection of stone tool forms over time and to different extents.

Fast-tool-servo-controlled shear-thickening micropolishing

Polishing-based post-processing is essential for removing the undesired surface diffraction on diamond-turned microstructured surfaces that is enhanced by periodic tool marks. To overcome challenges in existing micropolishing methods, a fast-tool-servo-controlled shear-thickening micropolishing method was proposed for the non-contact and controllable polishing of microstructured surfaces. The operating kinematics and material removal mechanism are modeled analytically and investigated experimentally. The comprehensive principal stress in front of the rake face of the tool is found to mainly contribute to the material removal. The fast tool servo can tune the principal stress and the viscosity of the slurry by flexibly adjusting the gap width between the surface and the tool edge. Thus, the material removal can be controlled at any operating position. Meanwhile, although the material removal rate is nonlinearly related to the rotation radius and gap width, the constraint between these two factors is linear for achieving a fixed material removal rate. Finally, the feasibility of the proposed micropolishing method is demonstrated by successfully polishing rotationally symmetric and asymmetric microstructured surfaces to achieve improved surface smoothness and conformal surface shapes.

Tool Edge Preparation Based on Gas–Solid Two-Phase Abrasive Flow

Tool Edge Preparation Based on Gas–Solid Two-Phase Abrasive Flow

Cutting temperature measurement using a novel near-infrared two-color pyrometer under dry and wet cutting of Ti‐6Al‐4V alloy

Due to the poor thermal properties of titanium alloys, heat generated and accumulated in the cutting area significantly affects tool life and workpiece quality. Although some methods have been proposed to measure the cutting temperature during machining titanium alloys, there still exist disadvantages including low spatial-temporal resolution, low measuring accuracy, restricted usage environment, etc. In this paper, a novel near-infrared two-color pyrometer system is developed and applied to measure the cutting zone temperature under dry and wet cutting of Ti‐6Al‐4V alloy. The developed pyrometer can eliminate the emissivity effect and shows a good linear relationship between the output signal ratio and the calibrated temperature. Meanwhile, the developed pyrometer exhibits good dynamic response and high measuring accuracy when measuring tool edge temperature and chip temperature in dry cutting conditions. In addition, a reliable sealing for cutter assembly is developed to overcome the influence of cutting fluid on the optic-fiber probe and the developed pyrometer can measure the tool edge temperature quickly and accurately in wet cutting conditions. In summary, the novel near-infrared two-color pyrometer system is validated to be quick responsiveness, high measuring accuracy, and good working stability when monitoring the cutting zone temperature under dry and wet cutting of Ti‐6Al‐4V alloy.

Analysis and prediction of residual stresses based on cutting temperature and cutting force in rough turning of Ti–6Al–4V

Turning is a typical machining process, which is widely used in the manufacturing process of parts. The residual stress introduced by turning has a significant influence on the mechanical properties, fatigue performance, and service safety, and is one of the key factors affecting the fatigue life of parts. Conventional residual stress prediction models based on cutting parameters cannot consider all the influencing factors of turning and are strongly dependent on the specific cutting environment and tool, so they have limitations. Therefore, a residual stress analysis and prediction method based on cutting temperature and cutting force is proposed in this paper for the rough turning process of Ti–6Al–4V. Firstly, the sensitivity analysis of turning residual stress is carried out on eight cutting variables to determine the key cutting variables affecting the residual stress. Subsequently, the influence of the above key variables on residual stress is analyzed from the perspective of cutting temperature and cutting force. Finally, the residual stress prediction model based on cutting temperature and cutting force is established. The results show that the three variables that have the greatest influence on residual stresses are friction coefficient, tool edge radius, and cutting speed. The friction coefficient and tool edge radius affect the thickness of the residual stress layer. The cutting speed has little effect on the thickness of the residual stress layer, but increasing the cutting speed will lead to the transformation of residual stress to tensile stress. The relative error between the predicted value and the simulated value of residual stress is less than 6%, indicating that the prediction model has high accuracy and can effectively predict the residual stress. The prediction method proposed in this paper is not limited by the specific turning condition and provides a new perspective for the analysis and prediction of turning residual stress.