Tool Wear Characteristics Research Articles

Wear characteristics of nano TiAlN-coated carbide tools in ultra-high speed machining of AerMet100

In this paper cutting experiments of AerMet100 (52 HRC) using nano TiAlN-coated carbide tools with cutting speed from 250m/min to 7000m/min are carried out. The cutting tool wear characteristics under ultra-high cutting speeds are examined and the corresponding mechanisms are analyzed. The focus is put on the tool wear characteristics and mechanisms at cutting speed above 500m/min. The influences of cutting temperature and workpiece dynamic mechanical properties on tool wear are discussed. The results show that the tool wear mechanism is highly influenced by cutting temperature and workpiece mechanical properties. At cutting speed of 500m/min the dominate wear mechanism is micro chipping and fracture due to the cutting force vibration and cold welding of contacting materials between cutting tool and workpiece. At higher cutting speed from 1000m/min to 7000m/min the predominant tool wear mechanisms are abrasion, adhesion, and fracture due oxidation, and thermal softening, and grooving by hard grains. The roughness of tool flank at this cutting stage decreases with the increase of cutting speed due to the high thermal softening. The increase of workpiece material brittleness with the increase of cutting speed lowers the elastic rebound of machined surface and reduces the tool wear rate.

Machining Performance Study on Metal Matrix Composites-A Response Surface Methodology Approach

Problem statement: Metal Matrix Composites (MMC) have become a leading material among composite materials and in particular, particle reinforced aluminum MMCs have received considerable attention due to their excellent engineering properties. These materials are known as the difficult-to-machine materials because of the hardness and abrasive nature of reinforcement element-like Alumina (Al2O3). Approach: In this study, an attempt has been made to model the machinability evaluation through the response surface methodology in machining of homogenized 10% micron Al2O3 LM25 Al MMC manufactured through stir casting method. Results: The combined effects of three machining parameters including cutting speed (s), feed rate (f) and depth of cut (d) on the basis of three performance characteristics of tool wear (VB), surface Roughness (Ra) and cutting Force (Fz) were investigated. The contour plots were generated to study the effect of process parameters as well as their interactions. Conclusion: The process parameters are optimized using desirability-based approach response surface methodology.

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.

Effect of Run-Out on Tool Wear Characteristics and Cutting Forces in Micro Ball End Mill

Effect of Run-Out on Tool Wear Characteristics and Cutting Forces in Micro Ball End Mill

Magnetic abrasive finishing of cutting tools for machining of titanium alloys

Uncoated carbide tool surfaces are conditioned using magnetic abrasive finishing (MAF) to improve the tool wear characteristics by reducing friction between the tool and chip. The configuration of the magnetic particle chains that drive the abrasives plays an important role in surface finishing with minimal damage to the tool cutting edges. Roughnesses of less than 25nm Ra on the flank and nose and less than 50nm Ra on the rake can be achieved. In turning of Ti–6Al–4V alloy rods (at 100m/min cutting speed), MAF-processed tools exhibited tool lives of up to twice as long as unprocessed tools.

902 Ni基耐熱合金のニアドライ切削における工具摩耗特性

902 Ni基耐熱合金のニアドライ切削における工具摩耗特性

Wear Characteristics of Various Diamond Tools in Cutting of Tungsten Carbide

Face cutting of tungsten carbide was conducted using two monocrystalline diamond tools and three polycrystalline diamond tools to investigate the wear characteristics in terms of the crystal structure and composition of the diamond. It was found that the wear of the monocrystalline diamond tool depends on the crystal planes that form the rake face and flank face of the cutting tool, and a cleavage fracture occurs when the cutting force acts as a shear force on the (111) crystal plane. The binderless nano-polycrystalline diamond tool exhibits excellent wear resistance beyond those of the sintered polycrystalline diamond tool and chemical vapour deposition polycrystalline diamond tool, as well as better wear resistance than the monocrystalline diamond tool.

On-Machine Inspection Method for Superduty Lathe Based on Improved Laser Triangulation

In the development and application of superduty lathe process, the size measurement of a large workpiece is a key issue of quality control because the cutting process of large workpiece is high linear speed and time-consuming . A novel surface position information acquisition method for rotational object is proposed. The method uses high speed linear CCD to acquire image sequences, adopts image restoration technique to resolve clear images of laser spot from the image sequences, identifies sub-pixel center point of laser spot with correlation information among the clear frame-to-frame images, then resolves surface position information of rotational object with triangulation principle. Therefore, defects of existing laser triangulation for high-speed rotational object measurement are overcome. According to the resolved surface position information of rotational workpiece, the stability of accuracy, tool wear and vibration characteristics of superduty lathe can be evaluated.

Study on tool wear characteristics in diamond turning of reaction-bonded silicon carbide

Tool wear is one of the most critical problems in machining hard, brittle materials. In the present work, diamond turning experiments were performed on reaction-bonded silicon carbide, and the tool wear characteristics were investigated. A special kind of wear pattern, namely periodical groove wear, was identified on the flank face of the tool, where the periodicity of the microgrooves was the same as the tool feed. Geometrical analysis showed that the periodical groove wear was caused by the tool feed marks on the machined surface. Laser micro-Raman spectroscopy indicated that the high-pressure abrasive wear at the tool–workpiece interface dominates the wear behavior, rather than the diamond–graphite transformation. By swinging the tool around its curvature center during the cutting process, the periodical groove wear pattern was suppressed, and the tool wear was reduced significantly.

Multi-Objective Inversion Design of Cutting Head by Hard Rock Boring Machine Based on Fuzzy Theory and Genetic Algorithms

Along with the shearer's developed in the mining process, especially the rock tunnel boring roadway driving has become a major factor restricting the efficiency of coal, development of a suitable rock tunnel boring machine is very important, this paper use of rock excavation and after the release of stress concentration broken rock rolling theory, inverse problem approach using indirect parameters of the cutting head of, on the cutting head of the energy efficiency and the lowest maximum, minimum tool wear characteristics of multi-objective, were normalized, transformed into single objective problem, a genetic algorithm. The results showed that: the inversion of multi-objective design method is feasible to design a new type of driving hard rock cutting efficiency of institutions to provide 9%, compared with 20% reduction in energy consumption, lower tool wear 55.2% for the rock tunnel excavation needs.

Wear characteristics of various diamond tools in cutting of tungsten carbide

Wear characteristics of various diamond tools in cutting of tungsten carbide

Orthogonal Experiment Research on Tool Wear Characteristics in Diamond Cutting of Glass Soda-Lime

For the technology of diamond cutting of optical glass, the high tool wear rate is a main reason for hindering the practical application of this technology. In this work, orthogonal experiment of diamond cutting was carried out on soda-lime glass, and the result of tool wear test was detected by utilizing confocal microscope. Extremum difference analysis was employed to research the influence of different cutting condition on tool wear. The characteristics and mechanisms of tool wear in diamond cutting of glass were revealed and interpreted.

Corrosion Behavior of Different Thermal Spray Coatings and Hard Chromium Electroplating on A286 Super Alloy

Electrodeposited hard chromium (EHC) coatings have been widely used for improving wear characteristics of engineering tools and components. In the electrodeposition processes, in general solutions containing hexavalent chromium have been used. Hexavalent chromium is classified as a carcinogen compound, which causes health risks if used in production, and environmental problems due to the toxic character of the wastes [1]. In the present study plasma sprayed coatings (aluminum oxide, Co-28Mo-8Cr-2Si, tungsten carbide, chrome carbide) and electrolytic hard chrome coatings corrosion resistances have been compared through electrochemical polarization tests and immersion test in 0.1 N HCl aqueous solution.

Tool wear estimation using an analytic fuzzy classifier and support vector machines

A new type of continuous hybrid tool wear estimator is proposed in this paper. It is structured in the form of two modules for classification and estimation. The classification module is designed by using an analytic fuzzy logic concept without a rule base. Thereby, it is possible to utilize fuzzy logic decision-making without any constraints in the number of tool wear features in order to enhance the module robustness and accuracy. The final estimated tool wear parameter value is obtained from the estimation module. It is structured by using a support vector machine nonlinear regression algorithm. The proposed estimator implies the usage of a larger number and various types of features, which is in line with the concept of a closer integration between machine tools and different types of sensors for tool condition monitoring.

Fabricating micro-structured surface by using single-crystalline diamond endmill

A ball endmill made of single-crystalline diamond was used for cutting micro-structures on two kinds of mold materials, oxygen-free copper, and reaction-bonded silicon carbide (RB-SiC). The cutting performance of the ball endmill was investigated by examining surface roughness and form accuracy of the machined workpiece as well as tool wear characteristics. Micro-dimple arrays, micro-grooves, and micro-pyramid arrays with extremely smooth surface and high-accuracy profile could be obtained on oxygen-free copper without remarkable tool wear. When machining RB-SiC, however, tool flank wear takes place, leading to a rough surface finish. After the tool has worn off, the cutting performance of the endmill significantly depended on the tool feed direction. The optimum tool feed direction for micro-grooving was experimentally investigated.

Study on the Cutting Properties about Magnesium Alloy when Dry Turning with Kentanium Cutting Tools

In recent years, the machinability of magnesium alloy is concerned more and more by the public. In this paper, a study on the cutting properties of magnesium alloy AZ91D when dry turning with kentanium cutting tools is presented. It shows the cutting force measured by a data acquisition system which is made up of Kistler9257B piezoelectric crystal sensor dynamometer, Kistler5070A10100 charge amplifier and computer. The effect of cutting parameters on cutting force was studied, and the experimental formula was built. The tool wear and chip characteristics were observed with KYKY-EM3200 electron scanning microscope and EDAX PV9900 alpha ray spectrometer, while the surface roughness of the workpiece was measured with 2205 profilometer. Results showed that the cutting depth was the main influence factor on cutting force, followed by feed rate and cutting speed . The main form of tool wear showed to be diffusive wear and adhesive wear. The feed rate had the main influence on chip form and the workpiece surface roughness, cutting speed was less effective, the cutting depth was the least.

Neural network modelling of process parameters influence on tool wear for ball-nose end mills

Ball-nose end mills are used extensively in the manufacture of dies and moulds, aerospace components and medical devices. The machining process optimisation of these types of operations are challenging due to the large amount of parameters involved, such as axial path of cut, radial depth of cut, variable cutting speed along the cutting edge, variable chip thickness along the cutting edge, among others. This paper focuses on the main process parameters that affect tool wear during ball-nose milling operations. The parameters analysed are cutting speed, tilt angle and tool wear. Tool wear experiments were conducted with an indexable ball-nose end mill, machining blocks of P-20 mould steel at 30 HRC, under conditions similar to those used to produce sculptured surfaces in dies and moulds. Under the abrasive wear mode, a relationship was established between the undeformed chip geometry and the tool wear behaviour. The relation between process parameters and tool wear characteristics has been modelled with linear regression approach and artificial neural networks. The results have been compared with experimental work, indicating that proposed models are suitable to model this type of tool wear.

Tool wear characteristics of oil palm empty fruit bunch (OPEFB) particleboard

A series of machining experiments on the oil-palm empty fruit bunch (OPEFB) particleboard were carried out using a CNC router, to evaluate the tool wearing properties of the composite in comparison with a standard wood-material particleboard. A single-fluted tungsten-carbide router bit (12 mm dia., 18 000 rpm), with a rake angle of 15° was used in this experiment, in which the depth of cut was 1.5 mm and feed speed was 4.5 m/min. The router bit machined the edge of the board, moving along the full length before returning to repeat the cycle. The tool was examined for the extent of wear after complete failure had occurred. The result found that the wear pattern was similar in the oil-palm based particleboard and the wood-based particleboard, but the former is twice more abrasive compared to the latter. Microscopic examination of the cutter edge reveal a greater incidence of micro-fracture when cutting the oil-palm based particleboard, indicating the presence of hard impurities in the composite. From an economic perspective, the tooling cost for machining oil-palm based particleboard is estimated to be twice of the cost for machining wood-based particleboard. This study shows that the machining properties of oil-palm based particleboard will be a primary concern, if it is to find widespread application as a potential substitute for wood-based particleboard.

The Wear Characteristics of Cemented Tungsten Carbide Tools in Machining Oil Palm Empty Fruit Bunch Particleboard

A series of machining experiments on the Oil Palm Empty-Fruit Bunch (OPEFB) particle board were carried out using tungsten carbide tools, to ascertain the predominant mechanism of tool wear when machining this material. The experiments were carried out using a high speed lathe, which machined a rotating disc of the OPEFB particle board. It was found that mechanical abrasion and micro-fracture was the primary mode of tool failure when machining OPEFB particle board. The low cutting temperature recorded during the machining experiments provides compelling evidence to eliminate any significant effect of electrochemical and oxidation mechanisms on the wear of tungsten carbide tools. Therefore, the wear of cemented tungsten carbide tools when machining OPEFB particle board was predominantly by mechanical wear mechanisms. The results of this study implies that the high tool wear experienced during the machining of OPEFB particle board, may limit its use in the manufacture of value-added products, unless the boards are priced competitively in the market.

Frictional wear evaluation of WC–Co alloy tool in friction stir spot welding of low carbon steel plates

Abstract Tool wear is a key issue for the friction stir spot welding (FSSW) of steel plates, especially in the automobile industry. In this study, steel plates were welded 500× using FSSW with WC–Co alloy tools of two different compositions. The effect of the weld number on the joint strength and the tool wear characteristics were analyzed by using a non-contact, 3D measurement system, scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), and X-ray diffraction (XRD). The experimental results indicated that the tool suffered extreme wear and that the joint strength was affected by the worn tool shape after welding. This tool wear was attributed to the formation of a ternary W–Fe–O compound, oxidative wear of WC and fatigue of the Co binder.