Cutting Edge Preparation Research Articles

Effects of cutting angle, edge preparation, and nano-structured coating on milling performance of a gamma titanium aluminide

Gamma titanium aluminides are intermetallic alloys. Recently, they have been evaluated as important contenders for structural applications in the automotive and aerospace sectors. This is due to their excellent high-temperature performances and their significantly lower density compared to nickel-based superalloys. In this paper, an analysis of machinability of a gamma TiAl obtained via an electron beam melting (EBM) process is presented. The effects of tool geometry modifications, in terms of cutting tool angles and cutting edge preparation, were investigated. The reduction of radial rake angle and the drag finishing process for cutting edge preparation resulted in an increase of the tool life of the carbide end mills. Nanogradient tool coatings were also observed to affect tool wear during milling tests, and the results highlight that AlSiTiN coating performs better compared to CrAlSiN coating. A post-coating polishing treatment was also taken into account, and it allowed a further reduction of tool wear. The overall results indicate that the machinability of this difficult-to-cut material can be significantly improved by an adjustment of the cutting edge geometry, and by using an AlSiTiN coating system.

Effects of geometric structure of twist drill bits and cutting condition on tool life in drilling 42CrMo ultrahigh-strength steel

To investigate the influence of the geometric structure of coated cemented carbide twist drills on the drill tool life, drilling experiments of 42CrMo steel were carried out at various cutting parameters. The geometric structure parameters of the specially manufactured drill bits were designed by the multifactor orthogonal experiment method. The effects of cutting edge preparation, drill point geometry, and flute geometry on the tool wear were investigated by the range analysis and variance analysis. And their effects on chip pattern were also studied. Then the influence of cutting parameters on the tool life was investigated. Based on these investigations and extending the tool life, the optimized geometric structure was the honed cutting edge with a radius of 0.06 mm and conventional conical flank, and the corresponding cutting parameters were 80 m/min and 0.18 mm/rev. At last, the tool wear characteristics were discussed and the main wear mechanisms were abrasive wear, adhesive wear, coating exfoliation, and tipping.

On the honed cutting edge and its side effects during orthogonal turning operations of AISI1045 with coated WC-Co inserts

The design of the cutting tool microgeometry influences the thermo-mechanical load profile on the wedge. Applying the appropriate hone design stabilizes the cutting edge, leads to improved wear behavior and higher tool life. Higher process forces and temperature, induced by larger hone, can be described as a side effect of cutting edge preparation, which should also be observed. This paper presents the quality oriented cutting edge preparation via abrasive brushing. The influence of the hone design on process forces, wear behavior and tool life of coated inserts will be analyzed within a wide range of cutting edge microgeometries and process parameters.

Burr Suppression Using Sharpened Pcd Cutting Edge by Ultraviolet-Ray Irradiation Assisted Polishing

Optimized microscopic cutting edge designs could bring a significant improvement to high performance cutting. This article presents the application of newly developed cutting edge preparation technology to sharpen cutting edges of poly-crystalline diamond (PCD) tools with sub-micro meter radii. This new polishing method is called ultraviolet-rays irradiation assisted polishing. Materials would be removed by a mechano-chemical removal process combined with the photochemical reaction of ultravioletrays. After preparation of the sharp edge, the cutting edge radius became smaller than diamond grain size. Several cutting tests showed burr reduction in the cutting of non-ferrous metals and carbon fiber reinforced plastics (CFRP) owing to the decrease of normal cutting force by using the sharpened PCD cutting tool.

Cutting Edge Preparation to Enhance the Performance of Single Lip Deep Hole Drills

An improvement in the efficiency of the cutting process requires high tool performance. For the tool performance the microscopic cutting edge shape is very important. By preparing the cutting edge the tool performance can be improved due to the reduction of the cutting edge chipping and the creation of a defined stable edge rounding. In this study, the influence of a cutting edge preparation on the deep hole drilling process is investigated. The aim is to increase the feed rate by a specific cutting edge design.

TRANSNATIONAL JOURNALISM EDUCATION

Journalism educators in Europe are gradually implementing training aimed at breaching borders between national newsroom cultures. At the same time, a “European” journalism culture has yet to materialize on a significant scale in the continent's newsrooms. This article examines this disconnect via a case study of a new transnational journalism education program. Graduates of the Master's in French–German journalism program face challenges in locating jobs that utilize their abilities, in large part because the media world still seems locked into national ways of thinking about journalism. As a result, these future journalists often find themselves in a sort of limbo, armed with a cutting-edge preparation but stymied by a profession still waiting to advance to a pan-European mindset.

Cutting Edge Preparation by Means of Abrasive Brushing

The need for new cutting tool technologies is driven by the constantly increasing performance of machine tools and the rising market competition. Current research results show that an improved combination of the cutting edge macro- and microgeometry, together with an appropriate substrate and coating, leads to a significant enhancement of cutting tool performance. Furthermore, inappropriate cutting edge microgeometries cause, in addition to the higher production costs, a reduction of the tool life. Hence, it is essential to produce tailored cutting edge microgeometries with high precision and process reliability. This paper presents the influence of brushing process parameters on the size and the form of produced cutting edges of indexable inserts. This leads to a better understanding and higher quality of the cutting edge preparation process by means of abrasive brushes. Furthermore, the process reliability of 5-axes brushing is analyzed. An example of a tool life map presents the significantly enhanced tool performance through cutting edge preparation and its sensitivity towards varying the cutting edge microgeometry.

FEM of Saw Tooth Chip Formation under Different Cutting Edge

The generation procedure of saw tooth chip when PCBN tools orthogonal cutting hard steel GCr15 is emulated by FEM software ABAQUS in this study. The model effectively overcomes serious element distortions and cell singularity in high strain domain caused by large material deformation. The effects of cutting edge preparation on cutting force, cutting temperature and residual stress are analyzed. Results of FEM show that cutting edge preparation has a great impact on cutting procedure. Under the same cutting condition, cutting force, temperature and residual stress of sharp edge, honed edge and chamfered edge increases in turn, and three kinds of cutting edge have the same change rule in residual stress. Chamfered edge has a good temperature distributing, and it is the best edge preparation in hard cutting.

The Effect of Tool Geometry on the Machinability of Polyamide During Precision Turning

The cutting tool geometry plays a significant role on the performance of conventional machining operations, irrespectively of the work material. For instance, alterations in the cutting edge preparation will result in changes in tool wear rate, cutting forces, temperature, and machined surface finish. This article compares the performance of uncoated carbide tools with standard cutting geometry and tools with modified edge preparation during precision turning of polyamide with and without 30% glass fiber reinforcing. The results indicated that, in general, the turning force components are reduced with the tool nose radius and the specific cutting force (Ks ) decreased as feed rate is elevated, presenting values comparable to metallic alloys. In addition to that, the polyamide without reinforcing presented a three-fold increase in specific cutting force (Ks) compared with the reinforced composite. Finally, the surface roughness increased as feed rate is elevated and tool nose radius is reduced.

Cutting Edge Preparation for Cemented Carbide Milling Tools

After the grinding process, the cutting edges of cemented carbide milling tools tend to chipping. Chipping has a strong influence on the tool performance. For this reason, the cutting edges are further prepared. Additionally, a cutting edge rounding has an impact on the wear behavior and the process stability. For the cutting edge preparation of milling tools, magnetic finishing is a promising process. This paper describes the process of magnetic finishing. The influencing parameters, i.e. the process time and the distance between the cutting tool and the magnetic disks, are investigated. Furthermore, the effect of magnetic finishing on the tool life is demonstrated using the example of a milling process with titanium.

Development of a new rapid characterization method of hob's wear resistance in gear manufacturing—Application to the evaluation of various cutting edge preparations in high speed dry gear hobbing

Gear hobbing remains a cutting technology mainly dedicated to large-scale productions of gears for the automotive industry. The improvements in hobbing tool design are problematic due to the very long duration of wear tests and due to the application of special machine tools only available in production plants. In order to overcome these limitations and to accelerate the efficiency of the investigations, a new rapid testing method called “flute hobbing” has been developed on a standard five-axes milling machine widely present in research laboratories. This testing method has been associated with a software providing the geometry of each chip in hobbing. The correlation of the chip geometry with the wear of each tooth enables to discriminate the critical teeth of a hob in order to focus the development in this area of the cutting zone. This new methodology has been used to investigate the influence of the cutting edge preparation on the wear resistance of gear hobs made of PM-HSS in the context of dry high speed manufacturing. The application of the AFM technology to generate defined edge preparation has shown its efficiency to improve the tool wear resistance and has confirmed previous results.

Statistical Research on the Effects of Cutting Edge Preparation on Face Milling of Austenitic Stainless Steel Using FEM

Austenitic stainless steels are extensively used in the areas with high corrosion. The high heat resistance and strength make them difficult-to-cut materials. The tool life in machining austenitic stainless steels is restricted by the high cutting force and temperature which induce the tool wear and edge chipped. To achieve tool edge strength and reduce the edge-related problems, tool edge preparation is applied by introducing the chamfered and honed edges. In the current paper, the effects of the cutting edge preparation in face milling of austenitic stainless steels were studied using statistical method. The output cutting parameters as cutting force, temperature were obtained by finite element analysis. The purpose for this research is to give guidance to the tool edge preparation for machining stainless steels.

Five-Axis brushing for cutting edge preparation

The efficiency of cutting tools can be increased significantly by preparing the cutting edges. This article presents a brushing method for cutting edge preparation developed at the Leibniz University Hannover and shows the performance of tools prepared in this way using the example of an AISI1045 turning process.

Statistical Research on the Effects of Cutting Edge Preparation on Face Milling of Austenitic Stainless Steel Using FEM

Statistical Research on the Effects of Cutting Edge Preparation on Face Milling of Austenitic Stainless Steel Using FEM

Cutting edge preparation using magnetic polishing and its influence on the performance of high-speed steel drills

The purpose of this paper is to investigate the effects of cutting edge preparation on tool life and tool wear of HSS drills. The experiment first utilized an unconventional but cost-effective method of magnetic polishing for cutting edge preparation on HSS drills. Observations from SEM and profilometer showed that magnetic polishing can generate different sizes of cutting edge radii for HSS drills. Its polishing effectiveness depends on the shot media, the severity of mechanical impacts and polishing time. The polished edge-radiused drills demonstrate a remarkable improvement in tool life compared to unpolished sharp drills. For the drilling conditions investigated, edge radius ranged between 24 and 27 μm has the highest tool life performance. The performance of different drills was also assessed by the measurement of thrust and torque, hole diameter, surface roughness and drill wear. Results show that large edge-radiused drills are prone to produce undersized holes. However, for the same amount of flank wear, all edge-radiused drills initiate lower thrust force and torque increment than the unpolished sharp drill therefore they can tolerate larger flank wear and lengthen the tool life.

Cutting edge preparation to improve drilling tools for HPC processes

High material removal rate, high cutting parameters and, hence, high resultant forces are characteristics of high performance cutting. Due to these greater requirements on cutting tool material with respect to its strength and wear resistance, as well as the applied coating, the cutting edge design also gains in importance. By cutting edge preparation, the process reliability can be enhanced through a reduced chipping and a defined rounding along the cutting edge. In this research, the abrasive water jet blasting process was used to prepare different cutting edge designs of carbide twist drills prior to coating. Based on the results of drilling tests using high performance cutting conditions, it was determined that the high performance process can be effectively optimized with respect to workpiece quality and tool life by selectively varying the microscopic cutting edge form.

Finite Element Analysis of Precision Hard Cutting Using Different Cutting Edge Preparation

Machining hardened steels has become an important manufacturing process, particularly in the automotive and bearing industries. Hardened steel GCr15 with its harness between HRC50 and HRC65 is one kind of more difficult machining material. Abrasive processes such as grinding have typically been required to machine hardened steels, but advances in machine tools and a new cutting material of polycrystalline cubic boron nitride (PCBN) have allowed hard turning on modern lathes to seems to gain an ever increasing industrial acceptance as an economically and environmentally friendly alternative to many grinding applications. In this paper, based on large deformation theory and updated Lagrangian procedure, a coupled thermo-mechanical plane strain orthogonal precision cutting model with general finite element analysis software is developed to the influence of cutting edge preparation on the cutting of GCr15 with PCBN tool, such as cutting forces, shear angle, and cutting temperature. The three major designs of cutting edge preparation are used on most commercial cutting inserts: a) sharp edge, b) honed edge, and c) chamfer edge. The friction between the tool and the chip is assumed to follow a shear model and the local adaptive remeshing technique is used for the formation of chip. The calculated principle cutting forces are compared with published data and found to be in good agreement. The simulation results can be used as a practical tool both by researchers and toolmakers to design new tools with rational tool edge and to optimize the cutting process.

Cutting Force Experiment and Simulation by Hard Turning GCr15 Bearing Steel with High Speed Considering Cutting Edge Preparation

In this study, hard turning GCr15 bearing steel with high cutting speed is experimental investigated the influence of the CB7015WH insert with chamfer edge and Safe-Lock and the CB7015 insert with a combination of hone radius and a chamfer edge on cutting forces and surface roughness of machined surface. Experimental results show that the cutting forces of the chamfer edge and Safe-Lock is smaller than that of the combination of hone radius and a chamfer edge. Moreover, surface roughness of machined surface with the CB7015WH insert is better. A coupled thermo-mechanical 2D finite element model with general finite element analysis software Deform 2D.8.1 is developed for the influence of two kinds of inserts on cutting forces and effective stress. The simulation results are compared with experimental data and found to be in good agreement.

Influence of cutting edge preparation on the wear resistance in high speed dry gear hobbing

Gear hobbing remains a cutting technology where high speed steels continue to find wide applications in modern manufacturing practice. The improvements in hobbing tool design are problematic due to the very long duration of wear tests. The application of an analogy process called ‘fly hobbing’ has been developed on a five-axes milling machine so as to improve the productivity of the investigations. This process has been used to investigate the influence of the cutting edge preparation on the wear resistance of gear hobs made of PM-HSS in the context of dry high-speed manufacturing. An original edge preparation procedure, based on the abrasive flow machining technology, has revealed a great improvement of the tool life.

Investigation of cutting conditions and cutting edge preparations for enhanced compressive subsurface residual stress in the hard turning of bearing steel

Residual stresses in the machined surface and the subsurface are affected by cutting tool, workpiece, tool/workpiece interface, and cutting parameters, such as feed rate, depth of cut and cutting speed. The prediction of residual stress profile in the machined surface is difficult due to the lack of proper material model to depict the material behavior and the complex interaction among the dominant factors. In this paper, the effects of workpiece hardness, tool geometry as well as cutting conditions on the residual stress distribution in the hard machined surface are investigated using a newly proposed hardness-based flow stress model employed in an elastic-viscoplastic FEM formulation. Special attention is paid to the effect of cutting edge preparation on the beneficial as well as the penetration depth of the residual stress in the machined surface. Simulation using different cutting edge preparations, namely sharp edge, small hone, large hone, chamfer and different combinations of hone plus chamfer, are conducted to obtain residual stress profile on the machined surface. Numerical results show an optimal combination of large hone edge + chamfer and aggressive feed rate help to increase compressive residual stress in both axial and circumferential directions.