Tool Wear Mechanisms Research Articles

Evolution of tool wear and machining quality during dry milling of AlCoCrFeNi2.1 eutectic high entropy alloy

AlCoCrFeNi2.1, a new class of eutectic high entropy alloy (EHEA) has drawn significant interest owing to the lamellar structure of alternating face-centered cubic (FCC) and B2 phases. Properties such as high strength and high plasticity render the machining of this alloy challenging. Addressing this issue, the milling experiments were conducted under dry conditions to investigate the machining quality of AlCoCrFeNi2.1 EHEA as well as the tool wear. The cutting temperature and cutting force were measured to explain the changes in tool wear and machining quality. The tool wear mechanisms and evolution modes were clarified. Finally, the change of surface roughness and surface morphology under different parameters were analyzed and the characterization method of plastic flow marked by B2 phase was proposed. Results showed that both the cutting temperature and cutting force increase as the milling parameters become larger. The width of flank wear increases with the increase of the cutting speed and the feed rate when the volume of material removal volume is constant. The tool wear modes evolved differently with different cutting parameters, for instance, abrasive wear dominated while the cutting speed was less than 80 m/min, but for higher speeds up to 110 m/min, adhesive wear and coating peeling occurred. As the cutting speed increases further, crater wear on the rake face starts to arise in addition to the flank wear. Abrasive wear and adhesive wear with increasing feed rate were dominant until a certain threshold (0.10 mm/tooth) beyond which the coating peels off the tool. Furthermore, chipping occurred for a higher feed rate of 0.14 mm/tooth. In particular, the formation of tool adhesive wear is mainly caused by the FCC phase adheres. In terms of machining quality, larger cutting parameters will worsen the surface roughness and morphology as well as lead to deeper subsurface plastic flow. The research will be conducive to promoting the applications of AlCoCrFeNi2.1 HEA.

Influence of Tool Wear and Workpiece Diameter on Surface Quality and Prediction of Surface Roughness in Turning

In turning, tool wear and cutting vibration are inevitable, which have great influence on surface quality. Analyzing the influence mechanism of tool wear and cutting vibration on surface quality is important to achieve the accurate prediction of surface roughness before machining and improve machining quality. In this paper, a turning vibration experiment is conducted to reveal that the diameter of shafts is an important factor affecting the vibration amplitude and frequency. In addition, based on machining parameters, tool wear and workpiece diameter, this empirical model, the response surface method and a support vector machine are used to model and predict surface roughness. The fitting accuracy, prediction accuracy and generalization performance of the proposed methods are compared in detail. The results show that the response surface modeling method has the highest fitting accuracy, but the exponential empirical modeling method has the highest prediction accuracy and best generalization performance. Additionally, the prediction results indicate that the surface roughness increases with the increase in tool wear and decreases with the increase in workpiece diameter.

Comparative study of tool wear mechanisms in drilling ZrO2 ceramics using various tool types

Comparative study of tool wear mechanisms in drilling ZrO2 ceramics using various tool types

Investigation on the performance of spark plasma sintered ultrafine WC-Co cemented carbide end mills during high-speed precision milling of Ti-6Al-4V alloy

In this study, ultrafine WC-Co and WC-(Ti,W)C-Co cemented carbide end mills were fabricated via spark plasma sintering. The performance of those tools in the high-speed precision machining of Ti-6Al-4V alloy was investigated, focusing on the analysis of tool wear mechanisms, cutting performance, and machined surface roughness. The results reveal that adhesive wear emerges as the predominant wear mechanism influencing the performance of both tools. The addition of (Ti,W) C leads to high workpiece element enrichment on the flank face of the tool, increasing subsequently severe adhesive wear. WC-(Ti,W)C-Co displays a greater propensity for crack propagation and material chipping, culminating in premature tool failure with the formation of significant wear craters and cutting edge breakage. Conversely, WC-Co exhibits comparatively milder wear patterns and a reduced incidence of cutting edge chipping due to its inherent resistance to adhesive wear. Additionally, the comparison of the developed ultrafine cemented carbide tools with similar commercial tools demonstrates that WC-Co has superior cutting performance in terms of tool life, 1.5–1.8 times longer than the commercial tools. These findings provide guidance for optimizing machining strategies and developing advanced tool materials for high-speed milling titanium alloy.

Cutting performance and tool wear mechanism of corrugated helical PCD tool in milling Cf/SiC composites

Cutting performance and tool wear mechanism of corrugated helical PCD tool in milling Cf/SiC composites

Investigations on the machinability performance of Al2O3/TiCN CVD coated carbide tools in sustainable high-speed hard-turning of AISI 4340 alloy steel

Abstract This study investigates the effectiveness of CVD coated carbide inserts in turning hardened AISI 4340 steel at high-machining speed V=300,350m/min under sustainable dry cutting environment. Experiments were executed in accordance to Taguchi L4 orthogonal array and crucial machinability aspects tool life, tool wear progression and mechanism, cutting force, and surface roughness were evaluated in detail. The results of this study revealed that Al2O3/TiCN coating successfully inhibited the faster progression of tool wear at low cutting speed (300m/min), feed rate (0.05mm/rev) and depth of cut (0.1mm), thus delivering the highest tool life of 19.25 min and lowest cutting force of 76.8 N. However, better surface finish of 0.305µm was obtained at high cutting speed (350m/min), low feed rate (0.05mm/rev), and high depth of cut (0.1mm). Nevertheless, at high cutting speed (350 m/min) and feed rate (0.1 mm/rev), involvement of intense thermal-mechanical effects suppressed the effectiveness of coating and tool completed its useful life at 9.24 min. Severe flaking on the cutting edge was observed at high machining parameters. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis revealed that adhesion, oxidation, and small scale chipping and abrasion were the primary wear mechanisms attributing in competing the tool life criteria (Vb=300µm) in all cutting conditions. Furthermore, it was established that the cutting force and surface roughness increased with increasing tool flank wear due to coating delamination, material adhesion and tool chipping. This research emphasizes the significant potential of adopting Al2O3/TiCN coated carbide inserts for high-speed industrial hard-turning of AISI 4340 steel.

Physical Simulations of the Tool Degradation in Friction Stir Welding

Abstract The present investigation is part of a comprehensive failure study of friction stir welding (FSW) tools, where experimental non-destructive and destructive evaluations are combined with analytical- and physical- simulations of tool wear mechanisms. This paper focuses on the research methodology and the primary results of Gleeble simulations of thermal- and mechanical-cycle effects on an H13 steel material widely used for FSW tools for welding aluminum and magnesium alloys.

Cutting performance and wear mechanism of submicron and ultrafine Ti(C, N)-based cermets

The complex thermal-mechanical coupling among Ti(C, N)-based cermet tool, workpiece and chip affects immensely the tool life, machining quality and costs during high-speed cutting, which makes the investigation on wear mechanisms of tools quite important. In this work, submicron and ultrafine Ti(C, N)-based cermet tools were prepared by vacuum sintering technology, and the cutting performance of the tools was evaluated by continuous dry cutting. The aim of this work is to unravel the wear mechanisms of submicron and ultrafine Ti(C, N)-based cermet tools based on the cutting performance and wear characteristics of both the cutting tools and chips generated during high-speed cutting. The Vickers hardness, flexural strength and tool lifespan of ultrafine Ti(C, N)-based cermets are significantly superior to those of submicron Ti(C, N)-based cermets because of grain refinement strengthening and the improved distribution of metal phases. Tool wear depends to a large extent upon the contact states and heat transfer ability at different locations of the tool edge, which are characterized by simultaneous action and mutual transition from abrasive, adhesion, surface fatigue and oxidative wear. Overall, ultrafine Ti(C, N)-based cermet tools with excellent comprehensive properties exhibit a distinctly reduced tool wear at different wear regions.

Analysis of Chip Morphology in Heavy Milling of 508III Steel Considering Different Tool Wear Conditions.

During the process of chip formation, the chip is subjected to extrusion pressure, friction, heat, and a strong chemical reaction. The chip's macro and micro morphology, to a certain extent, reflect the condition of the tool during the cutting procedure. Therefore, researching the macroscopic and microscopic morphology of the chip's surface in response to different tool wear conditions is of great significance to reproducing the cutting condition and analyzing the tool wear mechanism. This paper focuses on the chips formed by milling the difficult-to-machine material 508III high-strength steel. Firstly, the 508III steel milling experiment is carried out at the actual machining site to collect chip data under different tool wear conditions. Next, the free surface morphology of chips and the bottom surface morphology of chips are analyzed. Further, the chip edges are investigated, and their causes are analyzed. Finally, heavy milling 508III steel chip curl morphology analysis is performed. The research results play important roles in revealing the mechanism of tool wear and the relationship between chip morphology and tool wear. This information can be used to provide theoretical and technical support for monitoring the tool wear status based on chip morphology.

A meta-learning method for smart manufacturing: Tool wear prediction using hybrid information under various operating conditions

Accurate tool wear prediction during machining is crucial to manufacturing since it will significantly influence tool life, machining efficiency, and workpiece quality. Although existing data-driven methods can achieve competitive performance in tool wear prediction, their main emphasis is on fixed operating conditions with sufficient training samples, which is impractical in engineering practice. This implies that predicting tool wear values under variable working conditions with insufficient data is still a challenge owing to the difference in data distributions in complex tool wear mechanisms. Besides, having no access to samples in new conditions is another challenge for tool wear prediction in engineering practice. To address these issues, we develop a hybrid information model-agnostic domain generalization (H-MADG) method to provide appropriate initial model parameters that can be fast adaptative to the new conditions after fine-tuning. Additionally, we construct hybrid information as model input by fusing process information with temporal properties derived by neural networks, and the hybrid information can offer more useful prior knowledge about the machining process. Experimental results on NASA milling data show that compared with contrastive techniques, the RMSE of the proposed H-MADG method is reduced by an average of 36.81 %, which can achieve a low average RMSE value of 0.0904 with 15 cases under five different network architectures. We also investigate several crucial impact factors of the H-MADG method and summarize corresponding analysis and suggestions.

A dual-stage wear rate model based on wear mechanisms analysis during cutting Inconel 718 with TiAlN coated tools

Inconel 718 is recognized as the difficult-to-cut material. TiAlN coated tool is frequently applied in machining of such material, due to its excellent hot hardness and oxidation resistance. However, research on the wear rate model during the cutting of Inconel 718 with TiAlN coated tools is limited. Therefore, this paper proposes a novel dual-stage wear rate model to predict wear of TiAlN coated tools when cutting Inconel 718 using finite element (FE) simulation. The dual-stage model integrates impacts from adhesive wear, diffusion wear and abrasive wear, and includes two wear rate models for the initial wear stage and steady wear stage, respectively. Subsequently, an in-depth analysis of tool wear mechanisms is conducted through Energy Dispersive Spectrometer (EDS) and Scanning Electron Microscope (SEM) techniques. The analysis results reveal that the adhesive wear dominates in the initial wear stage, while the steady wear stage witnesses the concurrent involvement of abrasive wear, diffusion wear and adhesive wear. Moreover, extensive cutting experiments validate that the model can predict wear of the TiAlN coated tools with an error margin of less than 8.5 %.

Understanding tool cutting-edge microstructure and deformation mechanism induced by adhesive wear in the turning of nickel-based superalloys

Nickel-based superalloy has great potential in the aerospace industry as key components. However, difficult-to-machine characteristics have further limited its application. Thermal-barrier coatings of the titanium-based family on carbide tools offer exceptional performance in cutting superalloys, combining high-temperature stability and remarkable toughness. This work primarily concentrates on understanding cutting-edge microstructure and deformation induced by tool adhesive wear in the turning of nickel-based superalloys with experiment and modelling. The dominant tool wear mechanisms are revealed to be adhesive wear and abrasive wear by SEM/EDS. The microstructure of the cutting-edge interface is qualitatively and quantitatively investigated by SEM/EDS and EBSD. The adhesive layer thickness at cutting edge is about 10–30 μm. The GND density of WC grains at cutting edge is 15-20 × 1014/m. The nanomechanics properties of the tool wear interface were quantitatively evaluated by nanoindentation. The average hardness of WC and Ni-superalloy at cutting-edge interface is evaluated to be 15–19 GPa and 6.2–6.5 GPa, respectively. Further, the underlying deformation mechanisms induced by tool wear behaviours are revealed through the transient heat conduction model and cutting-edge stress distribution model. This research offers a framework and mechanism for the cutting tool wear surface/interface characteristics targeted to the difficult-to-cut superalloy materials.

Effects of longitudinal ultrasonic vibration on tool wear behaviors in side milling of GH4169D superalloy

The GH4169D superalloy, a novel Nickel-based material widely acknowledged for its exceptional high temperature strength and fatigue resistance properties, plays a pivotal role in the production of critical components of contemporary aero-engines. The material, however, falls under the category of a typical difficult-to-cut metallic material due to the substantial cutting forces and significant tool wear experienced during the machining process. In this paper, a method of longitudinal ultrasonic vibration assisted side milling (LUVM) was developed to extend tool life. The investigation primarily involved an analysis of tool wear behaviors, including milling force, tool life, morphologies of tool wear, and various underlying wear mechanisms in LUVM and conventional milling (CM) of GH4169D superalloy. The results demonstrate that LUVM exhibits the advantage of reducing milling forces and prolonging tool life in comparison to CM. Throughout the entire milling process, the maximum milling force of LUVM is consistently smaller than that of CM, displaying a comparatively slower growth trend. At the conclusion of machining, while CM reaches a maximum milling force of 360.3 N, the maximum milling force of LUVM (195.9 N) is significantly lower. The tool life of LUVM is 28.2 min, representing a 33 % increase compared to CM (21.2 min). Material adhesion, coating delamination, and built-up edge (BUE) phenomena can be observed on both the tool rake face and flank face in CM. LUVM contributes to mitigation of bonding phenomena, prevention of BUE formation, and avoidance of abrasive wear in comparison to CM. However, it is prone to lead to tool tip chipping. For CM, the tool wear mechanisms include adhesive wear, oxidation wear, abrasive wear and diffusion wear; whereas for LUVM, the tool wear mechanisms comprise of adhesive wear, oxidation wear and diffusion wear.

Tool wear induced multimode vibration and multiscale patterns in precision turning NAK80

Cubic boron nitride (CBN), with a hardness second only to diamond and an excellent chemical stability, is used to replace the role of diamond and machine precision/ultra-precision components in ferrous materials. However, the wear mechanisms of CBN tools and their wear-induced effects on machining system vibration seriously affect the machined surface quality. Therefore, this research focus on the wear characteristics of CBN tools in machining of NAK80. Based on the wear characteristics, the change in surface morphology and finish of the machined surface with tool wear was investigated. Meanwhile, the transformation of chip morphology at different wear stages was observed. Also, the effect of tool wear on the machining system vibration is analyzed by Butterworth filtering and Fourier transforming the cutting force signal. Research results show that the wear mechanisms of CBN cutting NAK80 are abrasive wear, oxidative wear and diffusive wear. Further, when the width of the flank wear of the CBN tool reaches 53 μm it causes multimodal vibration of the machining system, resulting in chattering patterns on the machined surface. As the width of the flank wear increased from 56.64 μm to 70.80 μm, the vibration frequency increased by 13.3 %. However, by reducing the feed rate from 5 μm/rev to 2 μm/rev, the vibration frequency can be reduced by 66.8 %. This study provides theoretical help in the research of wear of CBN cutting NAK80.

Understanding the effects of cutting conditions on vibrations, surface integrity, machining temperature and tool wear mechanisms in end milling of AISI D2 Steel

The study explores vibrations, and thermal and tool wear (TW) mechanisms during dry end milling of AISI D2 steel employing two-, four-, and six- flute designs of TiAlN-PVD coated carbide end mill cutting tools. Because of multi-physics interactions in machining zone, supervised machine learning is used to understand TW, machining vibrations (MV), surface roughness (Ra) and the temperature of machining zone (TMZ), and to correlate the surface characteristics. A dedicated full factorial design of experiments campaign involving flutes (Fn), feed rate (Fr), and depth of cut (Doc) as variables is carried out to learn tool-workpiece interfacial characteristics. Results revealed that MV, Ra, TMZ and TW improved 57.82 %, 87.11 %, 79.22 % and 79.40 %, respectively at Fn = 6, Fr = 300 mm/min and Doc = 0.5 mm. Supervised machine learning (neural networks) and non-dominated sorting genetic algorithm (NSGA-II) based results showed reduction in vibrations by 89.84 %, Ra 97.39 %, tool-workpiece interaction temperature by 56.86 % and TW by 57.07 % by understanding mechanistic correlations of machining parameters with performance metrics.

Effect of forward and reverse cutting on tool wear behavior in ultrasonic vibration-assisted milling of 3D needle-punched C/SiC composites

C/SiC composites have excellent mechanical properties such as high specific strength and high temperature resistance, and are widely used in aerospace fields. However, due to its special structure and material properties, the tool wear is severe when machining with conventional methods, and the processing quality is poor. The purpose of this paper is to reveal the progressive wear behavior, wear mechanism of the tool, and its effect on machining performance in conventional milling (CM) and ultrasonic vibration-assisted milling (UVM) of C/SiC composites under forward fiber cutting (FC) and reverse fiber cutting (RC). The material removal and heat transfer models were established, and the stress distribution characteristics of cutting -edge were analyzed by finite element method (FEM). Combined with the wear morphology, cutting heat, and cutting force, the tool wear behavior and mechanism in UVM and CM under FC and RC were studied, and their effects on machining quality were analyzed. The results show that there are great differences in heat transfer and removal process between FC and RC. In UVM, the introduction of ultrasonic vibration reduces the adhesion of fine chips, weakens the strong friction and scratching between the hard chips and the cutting -edge, and alleviates the tool wear. The flank wear VB and cutting -edge wear area WA in RC are larger than those in FC, the abrasive wear is intensified, the material even peeling under mechanical shock, and the adhesive wear is more serious. When the tool wear intensifies to a certain extent, the difference of the cutting process caused by mechanical anisotropy of C/SiC composites is weakened, and the surface micro-defects and surface roughness Sa change little under FC and RC. This research contributes to the realization of high-quality and low-cost processing of C/SiC composites.

Effects of chip breaker groove and tool nose radius on progressive tool wear and behavior when turning GH3536 nickel-based superalloys

Nickel-based superalloys are typically challenging to machine and often exhibit severe tool wear during the turning process, thus attracting substantial research attention. This study not only explores the tool wear mechanisms when turning GH3536 nickel-based superalloys but also introduces a focus on the role of tool geometry configuration. Tools with different chip breaker groove structures and nose radii were investigated, with results indicating the tool wear mechanisms were predominantly abrasive and adhesive. For the 04HA chip breaker, which has a 9° rake angle and a "V"-shaped bottom, there is a single point of impact with the chip during cutting, while the 04VP3 chip breaker, with a 15° rake angle and a flat bottom, has two points of impact with the chip during cutting, increasing chip deformation and favoring chip breaking, thereby suppressing the formation of built-up edge. Additionally, changes in the nose radius influenced the degree of work hardening and consequently influence the severity of notch wear, with the nose radius also impacting the chip flow angle. Based on this finding, a theoretical mathematical model describing the initial chip flow angle was established and validated. Additionally, an examination of the effects of varying operating parameters on tool life was conducted, revealing that cutting speed was the most significant factor affecting tool life, followed by feed rate and depth of cut.

A new approach for analyzing machining-induced damage in correlation with tool wear during dry drilling of CFRP/Ti stacks

The machining process of Carbon Fiber Reinforced Polymer/Titanium (CFRP/Ti) stacks presents significant challenges owing to the inherent inhomogeneity of CFRP and the low thermal conductivity of Ti. The drilled hole surface can experience machining-induced damage, such as delamination, fiber pull-out, and burr formation. The present study aimed to examine the influence of cutting parameters and coatings, as well as tool wear mechanisms, on the occurrence of machining-induced damage in CFRP/Ti stacks during dry drilling. Moreover, a new method called MATLAB-Assisted Image Processing (MAIP) is introduced to assess machining-induced damage, specifically delamination and burr formation, in the context of CFRP/Ti stack drilling. The use of advanced MATLAB-assisted image processing improves the precision of MAIP. The coefficient of repeatability is 0.001394. TiAlN-coated drills offer notable advantages, resulting in a 13% decrease in the maximum thrust force for CFRP and a 10% reduction for Ti. Furthermore, there is an 11% decrease in delamination compared to a tool that lacks a coating. The experimental findings revealed a significant correlation between machining-induced damage and the mechanisms of tool wear.

Investigating the Wear Mechanism of TiAlN/TiN PVD-Coated WC Inserts in End Milling of Incoloy 925 Under Synergy of Bio-Degradable Fatty Acids and Nano-Metallic Solid Lubricant

Abstract Rapid tool wear in machining difficult-to-cut material is a significant challenge since it is related to tool cost, surface integrity of machined components, and power consumption. The reduction in tool wear may be accomplished by cutting fluids, especially in modern biodegradable fatty acids. Because of its high lubricity, coconut oil is the best choice for lubricating fatty acids. However, this oil has poor heat transfer properties. Hence, to further improve its properties, copper (Cu) nanoparticles (NPs), which have a high thermal conductivity to cost ratio compared to other nanoparticles in addition to anti-frictional and anti-wear properties (due to self-repairing properties caused by their low shear strength and easy deposition on contacting surfaces), have been dispersed in coconut oil, thus creating a nano-lubricant (nanofluid). It is found that synthesized nano-lubricants perform better in thermo-physics and tribology than pure coconut oil. Further, research has been carried out on the combined effects of coconut oil and 0.3 vol% Cu-NPs on Incoloy 925's end milling performance and tool wear mechanism (viz., coating delamination, adhesion, abrasion, and oxidation). It is found that tool wear-rate is reduced, which in turn increases tool life, due to effective cooling and lubrication when nanofluid-based minimum quantity lubrication (NMQL)-assisted machining is performed rather than dry and pure oil-based minimum quantity lubrication (MQL) conditions. Consequently, energy consumption in machining and surface quality of machined components are improved.

Wear mechanisms of diamond segmenta in cutting of carbon fiber reinforced cement-based composite and optimizing in parameters

Carbon fiber reinforced cement-based composite material (CFRC) is a novel type of composite material that involves the incorporation of carbon fibers into ordinary concrete. This addition effectively enhances the tensile strength, deformation performance, and dynamic load resistance of reinforced concrete structures. Consequently, CFRC has found increasing applications in the construction industry. The objective of this research is to investigate the wear mechanisms of diamond tools during the sawing process of CFRC and offer guidance on cost reduction through the optimization of processing parameters. The wear analysis of diamond segments can be divided into two categories: matrix wear and diamond particle wear. The diamond particles can exist in different states, and the formation of voids resulting from the detachment of diamond particles is considered as a reference point. The analysis reveals that abrasive wear is the main mechanisms of matrix wear in CFRC sawing. The wear resistance is strongly influenced by the proportion of diamond particles in favorable states, which is determined by the applied loads and operating parameters. The proportion of diamond particles exhibits a clear variation with adjustments made to the feeding speed. Notably, an increase in feeding rate results in a significant decrease in the percentage of blunt particles, reducing it from 28% to 6%. To achieve a lower wear rate, a predictive model was established using Design Expert software based on the experimental results. The model demonstrated that a wear rate as low as 268.5 mm/m2 can be achieved with a flywheel speed of 78 r/min and a feeding speed of 90 mm/h. The optimization process, aimed at minimizing wear rate, was successfully carried out without compromising productivity.