Edge Preparation Research Articles

Surface integrity after hard turning using specially ground cemented carbides

In order to explore the effects of the tool geometry on the machining process, the aim of this project is to study the surface integrity generated in the 4142 alloy steel after straight turning with customized tungsten carbides cutting tools prepared with customized geometries, verifying their influence on residual stress and roughness behavior. Square cutting inserts were prepared from K10 hardmetal with PVD TiAlN coating varying edge preparation (or form factor) and nose radius. Taguchi methodology was applied for the design of experiments also varying feed rate. Results showed the major influence of feed rate and nose radius, over surface roughness, with the form factor parameter interfering at the components of cutting forces, which could also affect residual stresses and tool-lifetime due to wear.

Experimental Study on Chemical-Mechanical Synergistic Preparation for Cemented Carbide Insert Cutting Edge.

Typical edge defects in the edge region of a new cemented carbide insert without edge preparation include burrs, poor surface quality, micro-breakages, and irregularities along the edge. To address the problems in new cemented carbide inserts without edge preparations, a chemical-mechanical synergistic preparation (CMSP) method for the cemented carbide insert cutting edge was proposed. Firstly, the CMSP device for the insert cutting edge was constructed. Then, the polishing slurry of the CMSP for the insert cutting edge was optimized using the Taguchi method combined with a grey relation analysis and fuzzy inference. Finally, orthogonal experiments, the Taguchi method, and analysis of variance (ANOVA) were used to investigate the effect of the polishing plate's rotational speed, swing angle, and input frequency of the controller on the edge preparation process, and the parameters were optimized. The results showed that the best parameter combination for the polishing slurry for the cemented carbide inserts was the mass concentration of the abrasive particle of 10 wt%, the mass concentration of the oxidant of 10 wt%, the mass concentration of the dispersant of 2 wt%, and the pH of 8. The CMSP process parameter combination for the linear edge had the polishing plate's rotational speed of 90 rpm, the swing angle of 6°, and the input frequency of the controller of 5000 Hz. The optimum CMSP process parameter combination for the circular edge had the polishing plate's rotational speed of 90 rpm, the swing angle of 6°, and the input frequency of the controller of 7000 Hz. The polishing plate's rotational speed had the most significant impact on the edge preparation process, followed by the swing angle, and the effect of the input frequency of the controller was the smallest. This study demonstrated that CMSP is a potential way to treat the cemented carbide insert cutting edge in a tool enterprise.

High-Speed Laser Beam Welding of Magnesium Alloy AZ31 for Enhancing the Mechanical Properties

Laser beam welding is still the focus of research all over the world since new laser sources with more brilliance, higher power, or higher efficiency are being developed. High brilliance leads to thinner fibers when solid-state lasers are used. For welding applications, a thin beam, respective a small focus spot is recommended for low heat input resulting in less deformation. The edge preparation of the welding pieces must be as accurate as possible, and a zero gap is recommended. In earlier research, it was shown, that the gap bridging capacity could be enhanced by the wobbling of small focus spots, as well as refining the grain size in the weld zone by decreasing the focus diameter. Inventions in the optics, like the beam splitting into a core and a ring part, avoid the use of a scanner and can lead to better gap bridging. Nevertheless, the use of a brilliant beam, resulting in a small focus in combination with high power can result in very high welding velocities, just limited by the used machinery. In the present study, a disk laser with 4 kW maximum power and 100 μm focus spot was used to weld 2 mm thick magnesium AZ31 sheets at speeds up to 20 m/min. As expected, the seam width becomes smaller with raising velocity, and some underfill and access material occurred on the surface and the root of the welded sheets. Surprisingly, the texture of the weld seam changed from random at low velocity to a more pronounced texture at high speed with respect to the basal texture of the plate base material. This influences the mechanical behavior, namely the strain to fracture, of the welded joints positively. The high-speed weldments are compared to state-of-the-art weldments of magnesium AZ31, in terms of mechanical strength and elongation to fracture, based on the texture analysis.

Research on an epoxy resin magnetoelastic abrasive: Application in tool edge preparation

Magnetoelastic abrasive grains have low elastic modulus and magnetism, which can create magnetic brushes in magnetic fields. When magnetoelastic abrasive particles come into contact with a workpiece, they can cause deformation, which increases the effective contact surface area and improves machining quality and efficiency. A method for preparing epoxy resin magnetoelastic abrasives was proposed first. The magnetic particle micromorphology was detected through scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Secondly, based on the theory of particle-filled composite materials and mechanics, the representative volume element (RVE) model was developed using the finite element software ABAQUS. The size ratio of iron and silicon carbide filler particles, particle shape, and arrangement of stress and strain were found to further improve the magnetoelastic abrasive preparation process. To investigate the effect of time, abrasive size, tool speed, disc speed, and disc spacing on the flank face value, rake face value, and shape factor, double disc magnetic preparation was subjected to magnetoelastic abrasive. Compared to traditional drag finishing methods, the magnetoelastic abrasive demonstrated high efficiency and quality. Exploring the application of magnetoelastic abrasives, new technology and methods of edge preparation, and promoting progress in magnetic efficient processing and magnetic optical finishing technology is of great theoretical and practical value.

Effect of central hole edge preparation, coefficient of friction and spring-back on hole expansion ratio of automotive steels

The influence of the central hole-edge condition on the hole expansion ratio (HER) of four automotive-grade steel sheets is experimentally investigated in this work. The punched hole shows inferior HER for all selected automotive-grade steel sheets than the wire-electrical discharge machined (WEDM) hole. The finite element simulation approach is used to determine the influence of the coefficient of friction and spring-back on HER. With an increased coefficient of friction, the punch force increases. Material near the inner edge of the central hole comes out in the direction of the sliding punch in the presence of friction. Spring-back has a small effect on HER, and its importance increases for lesser HER materials.

Lower limb ulcers in people experiencing homelessness

The homelessness crisis in Poland poses a serious challenge to the state, with the number of homeless individuals exceeding 30,000 in 2019. In this paper we highlight one of the most common surgical issue of people experiencing homelessness – venous leg ulcers – and present current treatment guidelines. Homeless individuals, particularly exposed to inadequate living conditions, poor hygiene, and circulatory disorders, are at high risk of developing them. Venous ulcers are chronic wounds with prolonged and complex healing processes.They arise due to venous hypertension associated with chronic venous insufficiency and thrombosis. Often, specialized treatment is necessary, which is a challenge for homeless individuals due to difficulties in accessing regular care.The treatment of venous leg ulcers involves a multi-stage process. The gold standard for managing venous leg ulcers is compression therapy, which reduces edema and venous reflux. The TIME strategy outlines the approach to chronic wound management, emphasizing the importance of initial wound cleansing (surgically, enzymatically, or larvotherapy), infection prevention, maintaining proper moisture and wound edge preparation. This requires the use of suitable antiseptics, dressings, and wound hygiene.People experiencing homelessness face specific issues that necessitate a holistic approach, which includes health education, nutrition, and rehabilitation.

Research on Defects Control of Niobium Tungsten Alloy by Laser Welding

The laser welding experiment of Nb521 niobium-tungsten alloy with 1.0mm thickness was carried out, and the effects of different welding edge preparation states, including fast wire cutting + milling and slow wire cutting + no milling, on the weld formation were analyzed. The results show that the laser weldability of the niobium-tungsten alloy is very good. The welding parameters are in a wide range, and good weld formation can be obtained easily. The effect of the welding edge preparation states on weld formation is very small, and all of the welded joints are broken in the base metal zone far away from the weld beam. Based on laser welding, the forming analysis of argon arc repair welding was carried out. The defects such as cracks and oxidation could be controlled effectively by optimizing the welding process. When the ratio of argon arc repair welding is in the range of 30% to 50%, the welded joints still have good tensile properties. The average tensile strength reaches 98.9% of the base metal and the average elongation after fracture reaches 83.8% of the base metal.

Effect of pre-strain on edge formability of high strength steels for chassis applications

There is a high level of uncertainty in the prediction of edge cracking during the design and manufacturing of high strength sheet metal products. Edge ductility is a complex parameter to measure since it is not an intrinsic property of the material, but it also depends on the trimming strategy/parameters that have been applied to the edge (edge preparation method, cutting/punching clearance, etc.). Furthermore, most forming processes involve more than one operation where the material can be deformed in a first stage, then trimmed or punched and further deformed in a final forming step to obtain the desired shape. Therefore, in order to design a robust and safe forming process able to predict the risk of edge cracking, it is crucial to understand the influence of pre-strain on the residual formability of trimmed edges. This paper analyses the effect of different pre-strain levels and paths (uniaxial tension, plane strain and equi-biaxial stretching) on the sheared edge ductility of a Complex Phase (CP) steel and a high strength low alloy (HSLA) steel used for automobile chassis applications. To this purpose, rectangular specimens are cut out from pre-strained samples and punched. Hole Tension Tests (HTTs) in combination with Digital Image Correlation (DIC) are carried out to determine the edge fracture strain of undeformed and pre-strained samples. The results are discussed in terms of major strains obtained from DIC. The proposed methodology allows describing the edge cracking sensitivity of high-strength steel sheets as a function of the pre-deformation state and can be useful to predict the risk of edge cracking more accurately in forming simulations.

State-of-the-art and perspectives of cutting edge preparation and its effect on the cutting performance of titanium alloy

Titanium alloys are commonly used in industrial applications due to their exceptional mechanical and chemical properties. However, their low thermal conductivity and high chemical reactivity pose significant challenges in machining, leading to increased cutting forces, rapid tool wear, and poor surface quality. To overcome these issues, advanced cutting edge preparation techniques have been developed to enhance the machining performance of titanium alloys. This paper provides an overview of state-of-the-art cutting edge preparation techniques for titanium alloy machining and examines their effects on machining performance. It first presents a characterization method for cutting edge geometry and explores how it affects machining performance, demonstrating that strategic cutting edge preparation can significantly enhance performance by reducing cutting forces and improving surface finish. The paper also emphasizes the underlying mechanisms of cutting edge preparation and its impact on machining performance and subsequent cutting edge erosion. Finally, it concludes by discussing future research directions in this field, highlighting the need to develop new cutting edge preparation techniques and optimize existing ones. Overall, this paper serves as a valuable resource for researchers and engineers seeking to improve the cutting performance of titanium alloys in various applications.

Vertical tooth preparation technique in aesthetic zone: Report of two patients

Abutments can be prepared in fixed dental prosthesis using horizontal and vertical preparation techniques. In vertical preparation abutments are prepared without a finish line by introducing a diamond rotary instrument into the sulcus to eliminate the cementoenamel junction and creating a new prosthetic cementoenamel junction. Vertical preparation technique in fixed dental prosthesis allows us to retrieve biologically compromised situations. With vertical preparations and over contoured provisional crowns, one can control zenith positions and thicken gingival biotypes. This in time gives us long lasting, stable tissue aesthetics around definitive restorations. This article describes 2 patients whose dental abutments were prepared using vertical preparation technique and 12 months follow up for restoration of teeth in aesthetic zone. Vertical preparation technique provides feather edge preparation and with interaction between preparation, restoration and gingiva aid in gingival thickening and adaptation to new prosthetic cementoenamel junction (CEJ) achieving soft tissue stability over long term.

Controllable preparation of non-uniform tool edges by magnetorheological finishing

Controllable preparation of non-uniform tool edges by magnetorheological finishing

Experimental Study on Flexible Fiber Assisted Shear Thickening Polishing for Cutting Edge Preparation of Core Drill

To improve the cutting performance of the core drill, the flexible fiber assisted shear-thickening polishing (FF-STP) for cutting edge preparation was proposed to eliminate the microscopic defect and obtain proper radius of the cutting edge of the core drill. The flexible fiber was introduced into the shear-thickening polishing process to break the thickened agglomerates and improve the efficiency of cutting edge preparation. The influence of the polishing speed, abrasive concentration and the flexible fiber contact length with the core drill on the cutting edge radius r and surface morphology of the core drill edge was analyzed, and the drilling experiments were carried out after preparation, the cutting heat and drilled holes’ roughness were employed as evaluation indexes to evaluate the performance of the core drill. The results show that the cutting edge radius increases with the increase of polishing speed, abrasive concentration and contact length. However, too high a polishing speed and contact length reduce the abrasive particles involved in the polishing process, and then lead to a decline in preparation efficiency. Under the selected processing conditions, the cutting edge radius increases from the initial 5 μm to 14 μm and 27 μm with 4 min of treatment and 6 min of treatment preparation, respectively. The sharp cutting edge becomes rounded, the burrs and chipping on the cutting edge are eliminated, and the average roughness (Ra) of the flank face decreases from 110.4 ± 10 nm to 8.0 ± 3 nm. Nine holes were drilled consecutively by core drills after cutting edge preparation, and the cutting temperature and drilled holes’ roughness were recorded. The maximum cutting temperature (122.4 °C) in the process with the prepared core drill (radius r = 14 μm) is about 20 °C lower than that with untreated one, and the roughness of the drilled hole (Ra 510.5 nm) about 189.9 nm lower. The results indicates that FF-STP is a promising method for high consistency preparation of the core drill cutting edge.

Effect of edge radius on forces, tool wear and surface integrity under edge radius dominated tool-chip contact conditions

Cutting-edge micro-geometry is a crucial factor influencing chip formation and tool performance. This paper investigates the effects of varying cutting edge radius (36–70 µm) on machinability and chip morphology during finish turning Ti6Al4V. An increase in edge radius decreases the cutting to thrust force ratio and produces lower chip thickness due to the increase in plowing zone depth. The machining temperature for the 48 and 52 µm edge radius tools is lower compared to all other tools. At the initial stage, the edge prepared tools exhibit larger flank wear, whereas subsequent flank wears progression is slower for the prepared tools as compared to the sharp tool. BUE and premature chipping is reduced for larger edge radius tool due to better edge stability provided by cutting edge preparation. Beyond the 59 µm edge radius, the process force, machining temperature, tool wear, and surface roughness increased steeply due to the increase in the size of the plowing zone. In addition to cutting force and machining temperature data, surface roughness, tool wear measurements and XRD analysis show that a radius range of 50–55 µm results in optimum performance for finish turning Ti6Al4V.

Determination of Maximal Gap for Laser Welding

Nowadays laser welding is widely used in industrial applications. Often, steel sheets are welded without welding material by using this process. The research aims to determine the maximal gap size and the related welding parameters for the laser welding of a 3 mm thick steel sheet of S235J2 steel grade. During welding, a joint gap may occur due to inadequate edge preparation, which must be considered during the design of the technology. The result of the experiments is that using the Trumpf TLF 5000 turbo-type carbon dioxide laser of 4.5 kW power, 3000 mm/min welding speed, with a focus the maximal gap size is 0.10 mm, while at 2000 (mm/min) welding speed, with 5 mm above focus the maximal gap size is 0.27 mm which can be welded with acceptable seam quality.

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

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

Preparation of Cemented Carbide Insert Cutting Edge by Flexible Fiber-Assisted Shear Thickening Polishing Method.

Reasonable cutting edge preparation can eliminate microscopic defects and improve the performance of a cutting tool. The flexible fiber-assisted shear thickening polishing method was used for the preparation of cemented carbide insert cutting edge. The influences of the polishing angle and polishing speed on the cutting edge preparation process were investigated, and the cutting edge radius and K-factor were employed as evaluation indexes to evaluate the edge shape. A prediction model of the cutting edge radius was also established using the mathematical regression method. The results show that the polishing angle has a more significant effect on the cutting edge radius. The cutting edge preparation efficiency is the highest under the polishing angle of 10°, and the cutting edge radius increased from the 15 ± 2 μm to 110 ± 5 μm in 5 min. The cutting edge shape can be controlled by adjusting the polishing angle, and the K-factor varies from 0.14 ± 0.03 to 0.56 ± 0.05 under the polishing angle (from −20° to 20°). The polishing speed has a less effect on the cutting edge radius and shape, but increasing the polishing speed within a certain range can improve the efficiency of cutting edge preparation. The flank face roughness decreased from the initial Ra 163.1 ± 10 nm to Ra 5.2 ± 2 nm at the polishing angle of −20°, which is the best polishing angle for the flank face surface roughness. The ANOVA method was employed to evaluate the effective weight of the polishing angle and polishing speed on preparation efficiency. The polishing angle (86.79%) has the more significant influence than polishing speed (13.21%) on the cutting edge preparation efficiency. The mathematical regression method was used to establish the model of the prediction of the cutting edge radius with polishing angle and speed, and the models were proved rationally. The results indicate that the FF-STP is an effective method for the high consistency preparation of cemented carbide insert cutting edge.

The Precision Analysis of Cutting Edge Preparation on CBN Cutting Inserts Using Rotary Ultrasonic Machining.

This paper is focused on the issue of preparing the cutting edge microgeometry of cutting inserts made of cubic boron nitride (CBN). The aim of this research was to investigate the possibilities of rotary ultrasonic machining (RUM) for preparing asymmetric cutting edge microgeometries of various shapes (chamfers, circular, and elliptical rounding and their combinations) on a CBN cutting tool. In this article, a new type of advanced cutting edge preparation method is presented. CBN is relatively resistant to the most often used (abrasive) methods of cutting-edge preparation, due to its very high hardness (which is a prerequisite property for machining difficult-to-cut materials). Such hard materials could be processed using advanced manufacturing methods, and rotary ultrasonic machining (RUM) is one such method. Experiments have shown that RUM can be used for machining CBN. However, high hardness is not the only challenge here. For cutting edge preparation, it is necessary to achieve an adequate accuracy of size and dimensions. The presented paper analyzes the suitability of the RUM process for processing CBN inserts. The results of the experiment showed that this method can be used for preparing asymmetric cutting edge microgeometries with various shapes.

Cutting edge preparation with elastic bonded diamond grinding wheels: Influence of the interaction of metalworking fluid and grinding wheel on the grinding wheel properties and preparation result

The cutting edge preparation with elastic bonded superabrasive grinding wheels enables the accurate manufacture of customized cutting edges. This process necessitates highest accuracies of the machine and the kinematics. Up to now, no systematic investigations on the interaction of the metalworking fluid and the grinding wheel were done; those could alter the properties of the grinding wheel, and as a consequence the result of cutting edge preparation. The influence of this interaction on cutting edge preparation is investigated in this study using two different experimental setups. One setup where the grinding wheels interacted with the metalworking fluid in an aging chamber to speed up the aging process and one setup directly in a tool grinding machine, in which the grinding wheels were also applied for cutting edge preparation at different stages of aging. In the aging chamber, the interaction takes place under elevated metalworking fluid temperatures to accelerate possible interaction effects. The results revealed an increase in the diameter, width and weight of the grinding wheels and a reduction in hardness. These changes were more pronounced under the elevated temperatures in the aging chamber. This in turn resulted in a significant alteration in the geometry of the prepared cutting edges, which was not observed when the grinding wheels interacted with the metalworking fluid in the tool grinding machine. As a general result, to keep the properties of the grinding wheels approximately constant, continuous dressing cycles should be carried out. In addition, the grinding wheels should be stored in dry conditions when not using them. In this way, specific cutting edge geometries can be manufactured reproducibly.

Vertical Biologically Oriented Preparation Technique (BOPT)

The abutment tooth preparations for fixed prosthesis can be tried by a variety of methods, with the most common being the specified margin preparation and the vertical preparation or feather edge preparation. The second one was first utilised for prosthesis on abutment teeth that had periodontal disease and had been treated with resective surgery. In vertical preparation, we can alter gingival tissues to our desired contours using a rigorous, phased approach that includes preparation, provisionalization, and final prosthesis. The technique of vertical preparation in which finish line is absent, is a method in which the abutments are prepared by using a diamond rotary instrument into the sulcus to remove the existing cement-enamel junction and to make a new prosthetic cement-enamel junction controlled by the margin of the prosthesis.

Estimation of Drag Finishing Abrasive Effect for Cutting Edge Preparation in Broaching Tool.

In recent years, cutting edge preparation became a topic of high interest in the manufacturing industry because of the important role it plays in the performance of the cutting tool. This paper describes the use of the drag finishing DF cutting edge preparation process on the cutting tool for the broaching process. The main process parameters were manipulated and analyzed, as well as their influence on the cutting edge rounding, material remove rate MRR, and surface quality/roughness (Ra, Rz). In parallel, a repeatability and reproducibility R&R analysis and cutting edge radius re prediction were performed using machine learning by an artificial neural network ANN. The results achieved indicate that the influencing factors on re, MRR, and roughness, in order of importance, are drag depth, drag time, mixing percentage, and grain size, respectively. The reproducibility accuracy of re is reliable compared to traditional processes, such as brushing and blasting. The prediction accuracy of the re of preparation with ANN is observed in the low training and prediction errors 1.22% and 0.77%, respectively, evidencing the effectiveness of the algorithm. Finally, it is demonstrated that the DF has reliable feasibility in the application of edge preparation on broaching tools under controlled conditions.