Types Of Tool Wear Research Articles

Prediction model for single-point diamond tool-tip wear during machining of optical grade silicon

In this study, the influence of various machining parameters on the diamond tool-tip wear during single-point diamond turning (SPDT) of optical grade silicon was examined. The results from ten face turning experiments conducted with identical diamond inserts are presented. The tool-tip wear was recorded in each trial as a dependent variable of the three varying independent variables, which are cutting speed, feed rate, and depth of cut. The findings indicate that the tool wear was sensitive to a combination of the cutting parameter of low speeds and high feeds. The effect of cutting depth was found to be the least influential. It was further established that the rate of diamond tool-tip wear in face turning of optical grade silicon decreases with decreasing tool-workpiece engagement time per revolution. Experimentally, a combination of high cutting speed and moderate feed rate generated a good surface finish with minimal tool wear. At this combination, diamond turning is conducted with reduced machining time, high rate of production, and a significant reduction in machining cost. Overall, the predominant type of tool wear observed was flank wear with flank wear land characterized by notches, micro-grooves, and micro-chippings. The results further suggest the possibility of prolonging the ductile cutting process by proper selection and control of cutting parameters.

Fabrication of microchannels using rotary tool micro-USM: An experimental investigation on tool wear reduction and form accuracy improvement

Tool wear is an inevitable phenomenon and hence a prime challenge in micro-ultrasonic machining (micro-USM) process. Therefore, quantification and reduction of tool wear is essential to enhance the quality characteristics of machined microchannels. The present investigation establishes the quantitative relationships among the tool wear, form accuracy and material removal rate (MRR). This relationship is reported for the first time for rotary tool micro-USM (RTMUSM) process. An attempt has been made to understand the different types of tool wear in RTMUSM process. Later, a 2D geometrical model for the quantification of tool wear in RTMUSM process was developed. Further, the contribution of the different types of tool wear on the dimensional as well as form accuracies were evaluated. The experimental results revealed that the RTMUSM process is affected mainly by two types of tool wear (i.e. longitudinal wear and edge rounding wear). The lateral wear was revealed as negligible. It is suggested that the desired depth of channel (DOC) with best possible form accuracy of microchannels can be achieved by providing longitudinal wear compensation to the tool. The effect of process parameters such as tool rotation speed, work feed rate, power rating, slurry concentration and abrasive particle mesh size on total volumetric wear (TVW) of tool, MRR, dimensional and form accuracy of microchannels were also investigated. Additionally, the desirability approach was applied for optimization the RTMUSM process parameters for maximum MRR, DOC, form accuracy and minimum TVW and width of channel.

Taguchi S/N based optimization of machining parameters for surface roughness, tool wear and material removal rate in hard turning under MQL cutting condition

Minimum quantity lubrication (MQL) is adorned with improved machining performance and environmental sustainability. In this context, this paper presents the study of roughness parameters (Ra, Rq, Rz), tool wear parameters (VB, VS) and material removal rate (MRR) in MQL-assisted hard turning by using coated cemented carbide tool. As methodology, the Taguchi orthogonal array-based design of experiment and signal-to-noise ratio-based optimization have been utilized. Prior to this, the collected machining data have been tested to check the normal probability distribution. Furthermore, the analysis of variance determined the influences of cutting speed, feed rate and depth of cut on the aforementioned responses. In addition, different types of tool wear, prevailed in principal and auxiliary flank faces, have been identified. The quantitative analysis revealed that the cutting speed impacted the surface roughness; the depth of cut influenced the tool wear; the feed rate afflicted the material removal rate predominantly. Based on the imagery evidence the adhesion, abrasion, and built-up-edge were found as the governing wear mechanism.

Wear mechanisms of coated tools in high-speed hard turning of high strength steel

The high-speed hard turning experiments were carried out with coated tools. The chip features, tool life, and tool wear types were investigated to exploring the causes of tool wear. The experimental results indicated that the plastic deformation of the serrated shape chips was observed significantly. At the same cutting conditions, the cutting length of the carbide coating tool was longer than that of the cermet coating tool, while the cutting length of PVD TiAlN/TiN coating tool was longer than that of FF-TiCN/FF-Al2O3 coating tool. The rake and flank wear were the major wear types of the coated tools. The wear mechanisms involved abrasive wear, adhesive wear, micro-crake, coating spalling, chipping, diffusion wear, and oxidation wear.

Types of Tool Wear of AlTiN Coated Cutting Insert after Machining of Weld Overlay

Authors of the paper present different types of tool wear after machining of weld overlay with AlTiN cutting insert. Welded layer was created on roller made from S355J0 steel by Open Arc (OA) method also referred as Metal One Gas (MOG). Various forms of tool wear were documented by optical microscope. Microchipping of cutting edge, built up edge (BUE) and flank wear were identified on examined round insert in rough turning of hard cladding.

Monitoring and Evaluating Cutting Tool Wear using a IFM G4 Microscope

Evaluation of cutting tool wear is the technique generally used when monitoring cutting tool life. Different tool wear types increase depending on the cutting conditions and machined material on the cutting edge surface. The evaluated parameters depend on the tool wear type and where the tool wear is created. All these parameters are described by ISO 3685 standards. When a standard optical microscope is used, it is very difficult to determine the volumetric parameters and, in many cases, the actual (real) area of the tool wear. A standard optical microscope works on the basis of 2D screening. The new microscope works on the basis of 3D scanning, so the user has full information about the surface. This article is focused on the evaluation of the volumetric parameters on the cutting edge, on the size of the built up edge (BUE), and on the formation of the crater. Different coating types on the cutting inserts were used for the testing, and a IFM G4 microscope was used for monitoring and evaluating the tool wear.

Wearing Evaluation in Nickel Super-Alloys Turning for the Development of a Predictive Model for CAM Optimization

Nickel super-alloys are characterized by: high temperatures resistance, high hardness and low thermal conductivity. For this reason they are widely used in critical operating conditions. However, due to their excellent properties, nickel super-alloys are hard to machine. Tool wear is a major problem in nickel super-alloy machining; the high temperature at the tool rake face is a principal wear factor. Flank wear is the most common type of tool wear; it offers predictable and stable tool life evaluation. In this work, the authors present a flank wear evaluation in Inconel 718 turning, in order to develop a predictive model for CAM optimization. An appropriate database has been developed thanks to an experimental activity (VB as a function of: the cutting time T, cutting speed S and feed rate F). The objective of the optimization procedure is to maximize the Material Removal Rate (MRR) under the constraint represented by the flank wear limit. The developed procedure operates directly on the part program code, using the original one as starting point for the application of the knowledge about the wear behaviour. After the optimization phase the given output is represented by a new part program code obtained in accordance with: the maximum MRR within the respect of the wear limit. s and tables etc.

Principles of selection of cutting technological mediums for metal cutting

The article considers the principles of selection of cutting technological mediums for metal cutting. Rational use of effective cutting fluid is an important factor in improving of productivity and quality of metal working. Effect of cutting fluid depends on the rational choice of the specific conditions of the cutting, the predominant type of tool wear and tool and base material. In PJSC RPA “CNIITMASH” a complex of works on testing of a wide range of cutting fluids was carried out and recommendations for their use were developed

Milling Tool Wear Identification Using Information Fusion

Milling tool wear identification literature study, some information characteristics was generated by a number of possible milling tool wear. In theory, the characteristics of each of the information under the milling tool wear has a certain probability of occurring. DS evidence theory, belief functions used to express the size of the probability. the milling tool wear objects was identified through multi-sensor testing, then, measured the information features of each sensor belong to belief functions was obtained, then use the DS combination rule for information fusion, information fusion can be milling tool wear characteristics belong to the reliability function, the final determination based on certain criteria for determining status of milling tool wear type and size of tool wear.

Microstructural analysis of wear micromechanisms of WC–6Co cutting tools during high speed dry machining

This original study investigates the damages of WC–6Co uncoated carbide tools during dry turning of AISI 1045 steel at mean and high speeds. The different wear micromechanisms are explained on the basis of different microstructural observations and analyses made by different techniques: (i) optical microscopy (OM) at macro-scale, (ii) scanning electron microscopy (SEM), with back-scattered electron imaging (BSE) at micro-scale, (iii) energy dispersive spectroscopy (EDS), X ray mapping with wavelength dispersive spectroscopy (WDS) for the chemical analyses and (iv) temperature evolution during machining. We noted that at conventional cutting speed Vc≤250m/min, normal cutting tool wear types (adhesion, abrasion and built up edge) are clearly observed. However, for cutting speed Vc>250m/min a severe wear is observed because the behavior of the WC–6Co grade completely changes due to a severe thermomechanical loading. Through all SEM micrographs, it is observed that this severe wear consists of several steps as: excessive deformation of WC–6Co bulk material and binder phase (Co), deformation and intragranular microcracking of WC, WC grain fragmentation and production of WC fragments in the tool/chip contact. Thus, the WC fragments accumulated at the tool/chip interface cause abrasion phenomena and pullout WC from tool surface. WC fragments contribute also to the microcutting and microploughing of chips, which lead to form a transferred layer at the tool rake face. Finally, based on the observations of the different wear micromechanisms, a scenario of WC–6Co damages is proposed through to a phenomenological model.

Study of sudden tool failure in micro electro discharge milling

Micro electro discharge milling (MED milling) is a spark erosion method capable of micromachining prismatic and complex shapes using simple non-profiled tool. Tool wear poses major hurdle in the development of MED milling. This paper discusses the types of tool wear in MED milling and analyses factors causing exfoliation and sudden failure of micro tool. Process simulation of MED milling suggests using less viscous dielectric fluid, lower tool rotational speed and higher discharge gap to reduce the chances of unpredictable tool failure in MED milling.

Modeling and Simulation of Tool Wear During the Cutting Process

Experimental and analytic methods are still the main ways to investigate different cutting tool wear types. Numerous developments of numerical methods and simulations, associated to the existence of more and more powerful computer make possible tool wear studies using FEM. The main purpose of this work is to present a new approach to predict tool wear progression during cutting operation. In particular, an energy approach, linking the tool wear volume with the energy dissipated by friction is used. In addition, the interaction between residual stresses induced by cutting and the variation of tool geometry due to wear's mechanisms is investigated.In order to carry out this study, it is presented the experimental measurements of the wear of the tool, in particular the lost volume during the cut. Numerical simulation of orthogonal cutting operation using the commercial FEM code ABAQUS/Explicit is employed.

Analysis of the evolution of the Built-Up Edge and Built-Up Layer formation mechanisms in the dry turning of aeronautical aluminium alloys

Tool wear is one of the main parameters employed for evaluating tool life, due to its influence in the loss of quality of the manufactured parts. So, minimising tool wear is possible to maximise tool life and to optimise the manufacturing performance. Different mechanisms can cause the tool wear in a specific machining process. Adhesion wear is one of the tool wear mechanisms that can be present in a wider range of cutting temperatures. This type of tool wear can be produced by two different ways. On the one hand, direct adhesion wear is caused by the incorporation of tool particles to the chips. On the other hand, secondary adhesion wear is caused by the incorporation of fragment of the workpiece material to the tool. This affects to the tool wear in two ways. First, tool geometry changes by the material incorporation. In a second place, when these fragments are removed, they can drag out tool particles causing tool wear. Indirect adhesion can be located in the tool edge, giving rise to the Built-Up Edge (BUE) and/or in the tool rake face giving rise to the Built-Up Layer (BUL). BUL and BUE formation and their evolutions affects to the workpiece quality. In this paper a study of the BUL and BUE formation mechanisms, their evolution and their influence on the dry turned aeronautical workpieces surface quality has been achieved. In particular, this study has been developed using aerospace aluminium alloys such as UNS A92024 (Al–Cu) and UNS A97050 (Al–Zn). Results have shown that BUE is formed by mechanical adhesion mechanism. On the other hand, BUL is initially formed by thermo-mechanical causes. However, a secondary BUL has been detected as a consequence of the extrusion process of the BUE. Changes in BUL and BUE have been related with the changes observed in the roughness profile of the machined pieces and evaluated through the average surface roughness, Ra. So, a first relationship between the adhesion effects and the surface finish of the worked samples has been found. Obtained results have confirmed that BUE changes the tool position angle giving rise to a reduction of Ra.

Application of grey relational analysis in high-speed machining of hardened AISI D6 steel

This study reports an optimization of finish turning of hardened AISI D6 (60 HRC) cold work tool steel with ceramic and cubic boron nitride cutting tools using grey relational analysis. Optimization of the process parameters was performed using quality characteristics, i.e. tool wear, surface roughness, machining force and specific cutting force. Analysis of variance was used for observing the most influencing machining parameters on the quality characteristics. Evaluation of tool wear type and wear mechanism was done by tool makers’ microscope and scanning electron microscope analysis. The optimal process parameters were calculated using grey relation grade and confirmation test was performed. Based on analysis of variance results, the feed rate is the most significant controllable machining factor for the finish hard turning of AISI D6 according to the quality characteristics. Flank and crater wears were the prominent wear types on the ceramic and cubic boron nitride inserts. Grey relational analysis was successfully applied on optimization of high-speed finish hard turning of hardened AISI D6 using multi-performance characteristics.

The Mechanisms of PCBN Tools in Turning GH4169

This paper researched experiment results and analysis of PCBN insert turning nickel-based HSTR GH 4169. According to the curves and pictures, discuss the relationship of cutting parameters (cutting speed, feed and cutting depth) and some indexes (cutting force, cutting temperature and surface roughness). In addition, observed chip burr patterns, tool wear types and white layer statuses, and quantitatively analyzed their factors from the perspectives of cutting force and temperature, and put forward corresponding measures. The studies above were based on future research of quantification.

Modeling the effect of compacted graphite iron microstructure on cutting forces and tool wear

The characteristic mechanical (and physical) properties of compacted graphite iron (CGI) are contingent upon its unique microstructure. To model and simulate compacted graphite iron (CGI) in machining meaningfully, the metal's microstructure should not be overlooked throughout the process.In this work, modeling the microstructure of CGI in machining is implemented using a commercial general-purpose finite element package; ABAQUS/EXPLICIT (v 6.8). Segmental chip is modeled by the introduction of a new chip formation modeling technique. The cohesive zone elements are used to model the graphite–matrix interface. The methodology pursued to implement the finite element model is based upon an iterative interaction between comprehensive metallurgical investigations and finite element formulation of the problem in hand. Metallurgical examination of fractured and machined chips is not solely performed as a tool of validation, but rather as a tool of modeling.Vital model inputs are based upon metallurgical investigations of fractured CGI samples and machined chips. Subsequent comparisons between (1) simulated chips and (2) cutting forces trends, to experimental findings are used to validate the finite element model. The effects of cutting forces and temperature are comprehensively investigated to elaborate on their effects on tool wear. The effect of cutting speed (and feed rate) on cutting forces and cutting temperature determine the type of tool wear in CGI machining. Variation of the cutting speed triggers the deviation from mechanical to thermal tool wear mechanisms. This behavior is captured through the investigation of the cutting forces and simulated temperature trends in the finite element model. Other important findings are documented to serve as an optimization technique for tool material selection and machining conditions of compacted graphite iron (CGI) for which automotive and locomotive industries are of significant need to date.

Characterisation and online monitoring of wear behaviour of on-machine fabricated PCD micro-tool while vertical micro-grinding of BK7 glass

This paper deals with the wear behaviour of polycrystalline diamond tool of 0.5 μm grain size during micro-grinding of BK7 glass. It was found that tool wear caused both diameter and length reduction and G ratio was found to be 940. Observation of tool surface gave clear indication of edge chipping and abrasion type of tool wear where grain was pulled out and micro-cracks and built up edge mechanism are responsible for wear mode. Tool wear progress can be divided into three stages. In the initial stage, tool suffers insignificant wear, then intermediate wear, and finally, severe worn out tool. Huge pitting on bottom surface, chipped side wall, longer centre line and double side wall lining are the major phenomena of severe tool wear. Moreover, the increasing tendency of normal cutting force is found to support the evidence of tool blunting but cannot clearly indicate the severity of wear. Monitoring of root mean square acoustic emission signal is found to give an indication of tool topographic condition, i.e., sharpness and bluntness of cutting edge. Moreover, this signal can also envisage minor and major tool chipping condition. Hence, monitoring the AE signal can be a plausible way of monitoring PCD tool condition.

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.

The wear of single flute gun drill and tool life tests

In the machining industry, the demand for higher productivity can be gained with higher cutting parameters and also by developing new tools and work materials. Drill condition monitoring assists in choosing suitable cutting parameters for specific applications, e.g. for new work material. In addition, tool wear can be measured quite eas-ily in laboratory conditions.The object of this study was to ascertain the wear-ing of the gun drill and the measured wear types that the best indicate the tool condition. In the present study, dif-ferent tool wear types were found in the gun drill. To test these wear types, gundrilling tests were carried out by us-ing two different kinds of drill geometries. The best wear types for predicting the condition of a gun drill seem to be flank wear in the drill tip (CT), the average flank wear (VB) and the mean and maximum flank wear (VB, V´B) on the outside edge.

Wear patterns and mechanisms of cutting tools in high-speed face milling

High-speed machining has received important interest because it leads to an increase of productivity and a better workpiece surface quality. However, at high cutting speeds, the tool wear increases dramatically due to the high temperature at the tool–workpiece interface. Tool wear impairs the surface finish and hence the tool life is reduced. That is why an important objective of metal cutting research has been the assessment of tool wear patterns and mechanisms. In this paper, the wear performances of PCBN tool, ceramic tool, coated carbide tool and fine-grained carbide tool in high-speed face milling are presented when cutting cast iron, 45# tempered carbon steel and 45# hardened carbon steel. The tool wear patterns were examined through a toolmaker’s microscope. The research results show that the tool wear types differed in various matching of materials between the cutting tool and the workpiece. The dominant wear patterns observed were rake face wear, flank wear, chipping, fracture and breakage. The main wear mechanisms were mechanical friction, adhesion, diffusion and chemical wear promoted by cutting forces and high cutting temperature. Hence, the important considerations of high-speed cutting tool materials are high heat-resistance and wear-resistance, and chemical stability as well as resistance to the failure of coatings. The research results will be of great benefit in the design and the selection of tool materials and in the control of tool wear in high-speed machining processes.