Edge Geometry Research Articles

Effects of Tool Edge Geometry and Cutting Conditions on the Performance Indicators in Dry Turning AISI 1045 Steel

This article presents an experimental investigation and statistical analysis of the effects of cutting conditions on the machining performance of AISI 1045 steel using a wiper-shaped insert. Experimental findings are used to compare the machining performance obtained using wiper inserts with those obtained using conventional round-nose inserts as recently reported in the literature. In addition, the effects of process conditions, namely cutting speed, feed rate, and depth of cut, are analyzed in order to obtain optimum conditions for both types of inserts. The goal is to achieve the optimal machining outcomes: minimum surface roughness, resultant cutting force, and cutting temperature, but maximum material removal rate. A full factorial design was followed to conduct the experimental trials, while ANOVA was utilized to estimate the effect of each factor on the process responses. A desirability function optimization tool was used to optimize the studied responses. The results reveal that the optimum material removal rate for wiper-shaped inserts is 67% more than that of conventional inserts, while maintaining a 0.7 µm surface roughness value. The superior results obtained with wiper-shaped inserts allow wiper tools to use higher feed rates, resulting in larger material removal rates while obtaining the same surface quality.

Experimental analysis on the influence of the tool micro geometry on the wear behavior in gear hobbing

Gear hobbing is a well-established manufacturing process for cylindrical spur gears. The cutting edge of a hobbing tool is, among others, characterized by the cutting edge radius and the form-factor K. The magnitude of these parameters is ideally chosen based on the machining conditions given by the workpiece and cutting material and the cutting parameters as well as the gear and tool geometry. However, the influence of the cutting edge geometry on tool life and wear behavior is hardly known, which complicates an optimized tool design. Furthermore, the preparation process regarding the coating thickness distribution on the wear behavior is equally relevant. Therefore, the objective was to identify the influence of the cutting edge radius, the form-factor K, and the preparation process on the wear behavior of gear hobbing tools made of powder metallurgical high-speed steel (PM-HSS). Fly-cutting trials were performed as an analogy process for gear hobbing in order to study the wear behavior and identify the respective tool lives. The trials indicated that the form-factor K influences the wear behavior, while a variation of the cutting edge radius did not have a significant effect. A homogenous coating thickness could extend the tool life significantly.

Case Study: Drilling at the Cutting Edge of Performance With Shaped-Cutter Technology

_ Shaped cutters are not new to the industry. They were introduced decades ago when drilling environments began to change and more complex formations introduced new challenges, and they have been part of drill-bit technology portfolios since the 1990s. For many years, development teams have been investigating downhole conditions that were causing cutter damage and drilling dysfunctions, continually playing with the balance between materials and geometry. That knowledge has been a springboard for focused R&D efforts to improve cutter designs to contend with demanding drilling conditions and more complex wellbores. Today, shaped cutters push performance to new limits in applications that traverse multiple formations on a single run, from interbedded, to hard rock and abrasive formations, through sand, clay, sandstone, and limestone. Developing Shaped-Cutter Technology An entire suite of shaped cutters (Fig. 1) has been developed using the latest in materials research to address a range of challenging formation types and applications. Drilling engineers can place combinations of specialized cutters on a single bit to drill efficiently through complex formations. One of the advanced cutters (Fig. 1a) that emerged from these development efforts is a design that improves performance in hard formations. The resulting cutter has novel edge geometry to stand up to high-impact loads and a secondary chamfer on the diamond face that enables it to withstand higher loads than polycrystalline diamond compact (PDC) cutters. This allows it to maintain drilling efficiency in hard, interbedded formations, leading to a higher overall rate of penetration (ROP) for the interval. When drilling in hard, abrasive formations, heat generated from the rock-cutter interaction can break down the integrity of the cutter, leading to premature wear and reduced performance. Engineers focused on enhancing the improved cutter tip to develop a cutter (Fig. 1b) that remains cool in hard, abrasive formations and is particularly effective in sandstone, where it exhibits considerably less microfracturing and wear than traditional cutters. Complex runs often mean that bits must drill through very different formations, from interbedded, hard rock to more abrasive formations. To contend with these varying conditions, a cutter must be effective in high-impact loading conditions and still be functional at end of run. Another specialized cutter (Fig. 1c) was developed to deliver this balanced performance, reducing friction and heat generation at cutter/rock interface, breaking up rock cuttings, and enabling faster drilling and longer runs with a lower weight on bit (WOB) requirement for a given ROP. Conditions where point loading is required, such as drilling through evaporites or high-mud-weight environments and in drilling runs where WOB is limited, require a cutter with the ability to distribute more weight to a smaller portion of the rock. Baker Hughes designed a cutter (Fig. 1d) for these conditions that penetrates the formation more effectively than standard cutters by generating a larger depth of cut using the energy available to deliver faster drilling runs. The most recent addition (Fig. 1e) to the specialized cutter portfolio takes on even more demanding conditions with a design that delivers greater durability with the inclusion of secondary chamfering, a relief in the center of the cutter, and enhanced point-loading capability.

Multi-scale Edge-guided Learning for 3D Reconstruction

Single-view three-dimensional (3D) object reconstruction has always been a long-term challenging task. Objects with complex topologies are hard to accurately reconstruct, which makes existing methods suffer from blurring of shape boundaries between multiple components in the object. Moreover, most of them cannot balance learning between global geometric structure information and local detail information. In this article, we propose a multi-scale edge-guided learning network (MEGLN) to utilize the global edge information guiding the network to better capture and recover local details. The goal is to exploit the multi-scale learning strategy to learn global edge information and local details, thus achieving robust 3D object reconstruction. We first design a multi-scale Gaussian difference block (MGDB) to extract global edge geometry features for input images of different scales and adopt the attention mechanism to aggregate the extracted global edge geometry features of different scales. Second, we design a multi-scale feature interaction block (MFIB) to learn local details, which utilizes the multi-scale feature interaction to capture the features of multiple objects or components at multiple scales. The MFIB can learn and capture better as much local detail information as possible under the guidance of global edge information. Finally, we dynamically fuse the predicted probabilities of the MGDB and MFIB to obtain the final predicted result, which makes our MEGLN able to recover 3D shapes with global complex topological structures and rich local details via the multi-scale learning strategy. Extensive qualitative and quantitative experimental results on the ShapeNet dataset demonstrate that our approach achieves competitive performance compared with state-of-the-art methods. Code is available at https://github.com/Ray-tju/MEGLN .

Parametric model for a cutting edge contour of the geokhod cutting body blade

a parametric model for a cutting body blade cutting edge contour of geokhod, which is a new class of mining equipment. The research relevance is due to the need to create a unified methodology for forming the cutting body cutting edge for geokhods of various sizes, since the cutting edge design parameters are heavily dependent on geokhod geometry and force parameters. The research objective is to obtain parametric equations for determining the geometric coordinates of the points of the geokhod cutting body blade cutting edge in Cartesian coordinates. Methods of research. The paper describes the principles of parameterization of the complex geometry of geokhod cutting body blade cutting edge. Research methods include the study of blade edge geometry, as well as its design parameters dependence on geokhod’s force and design parameters. To achieve that, analytical dependencies were selected from the method of calculating the cutting body force parameters, and then parametric functions affecting the cutting body cutting edge geometry were selected. Results. As a result, a geometric model of the cutting body cutting edge in a parametric form was obtained. To demonstrate the formation of the blade cutting edge contact with rock based on the obtained parametric-time dependencies, a computer program was developed with the calculated values probability construction. The dependence between the cutting edge geometry and the geokhod design parameters dictated the modeling of the cutting edge shape for geokhods of different diameters. Conclusions. The obtained parametric expressions for calculating the coordinates of geokhod cutting body contact make it possible to build contact lines of the blade and the rock mass according to the input data. Is has also been proved that geokhod cutting edge shape depends on the geokhod diameter, and its geometric parameters will be individual for each type of geokhod

Identifying the lead angle limit to achieve required surface roughness in ball-end milling

When milling generally shaped surfaces with a ball-end milling tool, machined surface roughness and accuracy as well as machining productivity are often monitored. Improving one of these parameters often causes a decrease in the other monitored parameters. Therefore, knowing possible ways of influencing these parameters is important for achieving the optimum result, if possible, in all requirements. A deep understanding of how some technological parameters influence finished surface roughness is still lacking, as well as detailed knowledge of the relationships among some roughness parameters. In response, an experiment entailing machining of planar samples at different orientation angles was carried out to identify the influence of the studied parameters on the transverse roughness of the final surface. A finding was made that the resulting surface roughness is dependent on the cutting edge geometry of the particular ball-end milling tools used, and the achieving of the required surface roughness can be guaranteed by setting the specific lead angles. Furthermore, it was verified that a minimum lead angle limit can be found based on the geometric properties of the specific milling tool, and the relationship between the evaluated roughness parameters Ra and Rz was found as well.

Optimizing the cutting edge geometry of micro drill based on the entropy weight method

Optimizing the cutting edge geometry of micro drill based on the entropy weight method

Edge contacts accelerate the response of MoS2 photodetectors.

We use a facile plasma etching process to define contacts with an embedded edge geometry for multilayer MoS2 photodetectors. Compared to the conventional top contact geometry, the detector response time is accelerated by more than an order of magnitude by this action. We attribute this improvement to the higher in-plane mobility and direct contacting of the individual MoS2 layers in the edge geometry. With this method, we demonstrate electrical 3 dB bandwidths of up to 18 MHz which is one of the highest values reported for pure MoS2 photodetectors. We anticipate that this approach should also be applicable to other layered materials, guiding a way to faster next-generation photodetectors.

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

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

Topological and Spectral Properties of Wavy Zigzag Nanoribbons

Low-dimensional graphene-based nanomaterials are interesting due to their cutting-edge electronic and magnetic properties. Their large surface area, strong mechanical resistance, and electronic properties have enabled potential pharmaceutical and opto-electronic applications. Graphene nanoribbons (GNRs) are graphene strips of nanometer size possessing zigzag and armchair edge geometries with tunable widths. Despite the recent developments in the characterization, design and synthesis of GNRs, the study of electronic, magnetic and topological properties, GNRs continue to pose a challenge owing to their multidimensionality. In this study, we obtain the topological and electronic properties of a series of wave-like nanoribbons comprising nanographene units with zigzag-shaped edges. The edge partition techniques based on the convex components are employed to compute the mathematical formulae of molecular descriptors for the wave-like zigzag GNRs. We have also obtained the spectral and energetic properties including HOMO-LUMO gaps, bond delocalization energies, resonance energies, 13C NMR and ESR patterns for the GNRs. All of these computations reveal zero to very low HOMO-LUMO gaps that make these nanoribbons potential candidates for topological spintronics.

Analysis and Prediction of Roughness of Face Milled Surfaces using CAD Model

The condition for the designability and efficiency of the machining processes is that the part production process is chosen to meet the operational requirements based on the most accurate technological plans possible. One part of this is the planning of the required quality and roughness of the surfaces and achievement of the required values in the finishing. In this paper, a study on the predictability of surface roughness was performed using a CAD model based on theoretical roughness and validated by cutting experiments. The reported results show the effect of the feed rate change in face milling for two tools with different edge geometries in planes parallel to the feed direction.

Geometry Optimization for Increasing Fatigue Life of Pressing Packaged IGBT with SiC Chips and Silver Sintering Layers

A novel SiC IGBT module packaging structure is proposed. Pressing packaging with silver sintering is adopted. The thermal analysis is made with FEM. A maximum temperature of 137°C is obtained when the module is working, which leads to significant fatigue problem. The minimum fatigue life of the fundamental model is 106, and it occurs in the upper silver layer nearby the SiC. Five improved models with different silver layer edge geometry are analyzed. It turns out that the best geometry optimization in this study can lead to a fatigue life of 141, that is, 33% higher than the fundamental model. This shows that a very subtle change in the geometry of the silver layer edge can lead to significant improvement of the fatigue life of the module. This result can provide useful reference for the design the third generation IGBT device.

Assessment of Carbon Fiber Reinforced Plastic (CFRP) composites Using COPRAS Method

The influence of concrete strength and between concrete and CFRP composites considering the type of interaction, Exterior of reinforced concrete beams Optimum composition of CFRP composites for reinforcement and is to reach the number of layers. (i) machinability Chip removal mechanisms, cutting force, tool wear, Surface roughness, deformation and uncut of CFRP including properties of fibers; (ii) CFRP Cutting tool requirements for machining; and (iii) recent Industry solutions: cutting tools, coatings and Advanced edge geometry of technologies. CFRP composite, dry carbon fiber adhesive system. Tensile strength, tensile modulus, Air weight. From the result is based on is the result seen and got the Tensile modulus first grade, whereas the Density having the lowest rank. The value of the dataset for CFRP composites in COPRAS method shows that it results in tensile modulus and top ranking.

On the acoustic emission characteristics of airfoils with different trailing edge configurations

The present study experimentally and numerically investigates the flow past flat plates and NACA0012 airfoils with the different trailing edge (i.e., blunt, sharp, and rounded) and both end-rounded configurations on the far-field acoustic emissions and complex flow phenomena to determine the best edge geometry for low noise. The studies are conducted for various jet speeds of 20, 30, and 40 m/s (chordwise Reynolds numbers of 1.812 × 105, 2.72 ×105, and 3.62 ×105). It is observed that all the edge-modified flat plates show the highest directivity at an emission angle of 60° for all jet velocities studied. The comparison of power directivities between realistic and flat plate airfoils reveals that the realistic airfoils radiate lower acoustic emissions as compared to flat plate airfoils, albeit they show a common feature of downstream directivity. In general, the far-field acoustic emissions of both end-rounded plates are observed to be lower as compared to blunt, sharp, and rounded trailing edge geometries. The leading edge modification is also observed to reduce airfoil self-noise. The likely reason for the lower far-field acoustic emissions provided by both end-rounded trailing edged foils is due to the modification in the boundary layer characteristics owing to the presence of smooth flow around the rounded leading edge as well as reduced vortex strength as compared to the other foil geometries. Thus, the present study demonstrates that passive modifications of leading edge profiles are essential along with trailing edge for achieving lower acoustic emissions and higher noise reductions.

Improvement of the Wear Resistance of Circular Saws Used in the First Transformation of Wood through the Utilization of Variable Engineered Micro-Geometry Performed on PVD-Coated WC-Co Tips

Reduced performance of circular saws due to premature chipping of their teeth has been a critical issue in woodcutting industry for many years. This research examined the impact of surface coating and variable engineered micro-geometry of the cutting edges of carbide teeth (tips) on the wear resistance of circular saws used in primary wood processing. CrN/CrCN/DLC, CrN/AlTiN, CrN/CrCN, and CrCN/TiSiCN were deposited on tungsten carbide-cobalt (WC-Co) substrates using the cathodic arc evaporation technique. The CrN/CrCN coating proved to be the one with highest wear resistance and adhesion among those studied. No sign of delamination was observed around the indentation of the CrN/CrCN coating after the adhesion test. Furthermore, no abrasion, delamination or crack was observed on the surface of the CrN/CrCN coating after the three-body abrasion wear test. The results of the dry-sliding wear test revealed that CrN/CrCN coating significantly decreased the wear rate of WC-Co substrates by 74%, 66% and 77% at sliding speeds of 50, 100 and 250 mm/s, respectively. Afterwards, a CrC/CrCN coating was deposited on the teeth of conventional circular saws. Next, the cutting edges of teeth were modified through variable engineered micro-geometry. Tests were conducted at a sawmill with three series of saws: 1-coated and edge-modified, 2-coated and conventional edge geometry, and 3-uncoated and edge-modified. Wood processing was performed during two shifts of 480 min each. The width of the wear land was the criterion used as the wear index. The results of industrial tests showed that saws with edge-modified teeth had significantly less chipping and no breakage at their corners compared to the saw without edge modification (conventional saw). After 480 min of sawing, the wear rate of the coated saw with edge modification decreased by 46% and 16%, compared to the coated saw without edge modification and the uncoated saw with edge-modified teeth, respectively. Those values reached 73 % and 41%, respectively, after 960 min of sawing. The study shows that by optimizing the surface chemistry and the geometry of the cutting edge of WC-Co tips, tool life can be significantly increased therefore reducing downtime due to saw replacement and resharpening, thus significantly increasing productivity in the first transformation of wood.

Modelling edge effects at the interface in bonded joints using gradient functions in the mechanical properties of the adhesive: Application of the method to the Arcan test loaded in tension and shear

The design of bonded joints requires studies of stress concentrations due to edge effects. For complex joint configurations, the finite element method can be quite costly. The objective is to develop a fast and reliable numerical design tool for bonded assemblies. Therefore, an approach to design bonded assemblies is presented which aims to meet the needs of a design office, particularly in terms of calculation costs. The latter consists in reproducing the edge effects with a single element through the joint thickness using a modulus function. The concept was tested on Arcan specimen with two loading cases: tension (γ = 0°) and shear (γ = 90°). A 2D model under the elastic assumption is developed to describe the edge effects of the joint using Abaqus subroutines (UMat). The approach is set up to solve this problem in the form of two blocks. First, mesh refinement studies for bonded specimens loaded in tension were performed, within a good level of accuracy, on the free edge with the use of local discretization error estimation. After that, the effects of local geometry and modulus ratio are investigated. Afterwards, the von Mises stress at the interface level of the adhesive joint was used to identify a modulus function to describe the behavior of a joint with straight edge geometry for tension and shear loadings. The proposed approach has improved the performance of the model. Actually, the calculation is practically three times faster than for the conventional model.

Pulsed laser ablation of cutting edge geometries in alumina and zirconia composites at 200 fs and 2 ps

In this study, the feasibility of lasermachining cutting edges into mixed oxide ceramics such as alumina toughened zirconia (ATZ) and zirconia toughened alumina (ZTA) is evaluated. A simplified standard wedge geometry is machined into cylindrical samples by combining orthogonal and quasi-tangential laser machining strategies. For the experiments a laser source emitting a wavelength of 515 nm is applied and the pulse duration is varied between 0.2 and 2 ps. As target parameters the cutting edge radius and Sa value of the rake face are analyzed. The heat affected zone is analyzed by FIB SEM. An edge radius of 6.7±1.6μm at an Sa value of 0.115μm in the case of ZTA and an edge radius of 4.9±0.3μm at an Sa value of 0.125μm in the case of ATZ can be achieved. The results are promising for the application of laser ablation towards the manufacturing of cutting edges in oxide ceramics such as ATZ and ZTA.

Optimization of Edge Quality in the Slot‐Die Coating Process of High‐Capacity Lithium‐Ion Battery Electrodes

Understanding and reducing edge elevations at the lateral edges are crucial aspects to reduce reject rates during electrode production for lithium‐ion batteries (LIB). Herein, different process conditions to reduce edge elevations at the lateral edges of water‐based, shear‐thinning coatings in the production of LIB electrodes are presented. The reduction of edge elevations is transferred from state‐of‐the‐art electrodes to high‐capacity electrodes. The developed process configuration greatly reduces reject caused by cutting off the edge areas in the industrial roll‐to‐roll process for electrode production. Compared with state‐of‐the art electrodes, the reject rate for high‐capacity electrode production is significantly higher because the edge geometry in crossweb direction of the electrodes is wider. An optimization can be achieved by a combined adjustment of the coating gap and the slot‐die angle to the substrate (angle of attack) to affect the pressure field in the coating bead. Therefore, a systematic investigation and optimization of these process parameters are presented. In addition, the investigation of the process stability of the coating is required. Based on this optimization, a reduction of edge elevations for high‐capacity electrode coatings (5 mAh cm−2) of 69% and ultrathick high‐capacity electrode coatings (7 mAh cm−2) of 48% is possible.

Investigation of Water Films Shed From an Airfoil in a High-Speed Flow

Abstract The breakup of liquid films in high-speed flows is found in many applications. These include prefilming air blast atomization found in fuel injectors and shedding of droplet off of airfoils. In this work, a test rig has been developed and applied to study the breakup of water films from the trailing edge of an NACA 0012 airfoil placed in a high-speed air flow. The results provided reflect a new detailed dataset focused on air velocities above 75 m/s. Computational fluid dynamic (CFD) simulations were used to guide the development of the rig and the associated boundary and inlet conditions. In this work, air velocities up to 175 m/s were used with water films between 0.4 cm2/s and 3.6 cm2/s. The water film was introduced onto one surface through a series of 0.5 mm holes separated by 1 mm at a location 35 mm downstream of the leading edge of the vane. High speed video was used to document the sheet breakup behavior from the edge of the airfoil. Image analysis was used to identify the breakup length of ligaments formed. Laser diffraction was used 50 mm downstream of the trailing edge of the vane to determine the droplet size distribution and associated representative average diameters generated. A series of test conditions were run between 50 m/s and 175 m/s using multilevel factorial designed experiments. The results obtained were subjected to analysis of variance to generate correlations for breakup length and droplet representative diameters as a function of the conditions studied. The analysis was conducted on dimensionless versions of the variables studied to help connect the results to the physics of the situation. For example, rather than using air velocity to correlate the behavior, the Weber number (based on gas phase density and velocity) was used owing to its historical ability to describe liquid breakup processes. The results obtained are compared with other studies in the literature, and good agreement was found for the conditions at which a comparison could be made. It is observed that, for the conditions studied, liquid film thickness has little effect on the resulting droplet sizes—especially for the higher air velocity cases studied. The results also illustrate the sensitivity to choice of the characteristic length, which is generally consisted of trailing edge geometry or boundary layer thickness. In contrast, liquid film does influence the ligament breakup length, although the time to break up is less affected. Overall, the correlations developed provide engineering tools to help estimate ligament and drop size behavior for water films shed from airfoils in a high-speed flow.