Flank Wear Research Articles

Machinability of high strength cast iron alloys in dry-cut face milling operations

The advancement of cast iron alloy properties has enabled increased efficiency in automotive vehicles. Nevertheless, this progress is accompanied by a growing demand for more durable tools with higher resistance to successfully execute cutting operations. This work conducts an investigation of the machinability of different high-strength cast iron alloys. The parameter used was the machining time determined by the maximum flank wear of 0.4 mm. The machining process used was face milling with no cutting fluid, of which the cut depth and the penetration were kept constant at 1 and 60 mm, respectively. The input variables were the tool feed of 0.1 and 0.2 mm/tooth and the cutting speed of 230 and 350 m/min. The results showed that FV450 was the material that presented the highest wear values, followed by FC300(Mo+RG) and FC300(Mo). On the other hand, the FC250 demonstrated the longest machining time, resulting in an extended lifespan.

Tool life and wear mechanisms of CVD coated and uncoated SiAlON ceramic milling inserts when machining aged Inconel 718

In this study, an investigation has been conducted to fully characterise for the first time the tribological benefits of adding two different types of chemical vapour deposition (CVD) coatings to silicon aluminium oxynitride milling inserts with a chemical composition of (Si3N4 + Al2O3 + Y2O3), known by the trade abbreviation ‘SiAlON’, typically used to cut difficult to machine materials such as Inconel 718. The experimental tests compared the tool life, material removed and wear resistance of the two different CVD coated inserts against that of uncoated SiAlON ceramic milling inserts. Coating A was a multilayer CVD coating and had a composition of (TiN + TiCN + Al2O3), Coating B was a bilayer CVD coating and had a composition of (Al2O3 + TiN). It was determined that at 900 m/min the uncoated SiAlON ceramic milling inserts exhibited the least amount of wear and variation in cutting force when milling precipitation hardened Inconel 718 samples. Coating A demonstrated significantly lower adhesion to the SiAlON substrate but had higher tool life and material removal rates, Coating B demonstrated excellent adhesion to the SiAlON substrate. The interfacial bonding of Coating B allowed for much higher adhesion to the substrate, but it suffered from much lower tool life and higher rates of rake and flank face wear. The flank wear measurements concluded a cutting speed of 900 m/min to be the optimum cutting speed for machining Inconel 718 with uncoated SiAlON ceramic milling inserts.

Performance investigation of cryogenic treated-double tempered cutting inserts in dry turning of Ti–6Al–4V alloy

Dry machining of Titanium alloy Grade 5 (Ti–6Al–4V) with cryogenic treated, double-tempered KC5010 cutting inserts was examined. The impact of cryogenic treatment followed by tempering of the carbide inserts was investigated using microstructure analyses. The effects of constant depth of cut, cutting speed, and feed rate on machining variables (torque, force, surface roughness, temperature, and tool wear) were investigated. According to the experimental results, the cutting speed is the most important parameter that has a direct influence on the machining characteristics. Increased cutting speed and feed rate generate larger tangential pressures, allowing for a reduction in chip contact length; a shorter contact length results in reduced surface roughness and flank wear rate, respectively. The effects of cutting speed and feed rate on chip thickness were studied. Image analysis of the segmented chip was used to investigate the form and size of the saw-tooth profile of serrated chips. It was discovered that raising the cutting speed from 73 m/min to 160 m/min enhanced the free surface lamella of the chips and improved the visibility of the saw tooth segment. As cutting speed increases, all response parameters (torque, temperature, force, tool wear, and surface roughness) increase at the same time, by nearly 300%. Deep cryogenic treatment enhanced micro-hardness, resistance to wear, and toughness. As a result, there was reduced flank wear with tiny abrasion lines. Lower cutting speeds and feed rates resulted in less rake surface wear. Finally, the current study's convergence with earlier research was presented, indicating strong agreement between the two examinations.

Turning insert with lubricating passage along the normal plane for minimization of friction, cutting force and tool wear

This article proposed a strategy of generating lubricating passage on the turning insert to minimize the friction and cutting force. The lubricating passage comprised of a micro groove on the insert along the normal plane. The passage enabled favourable flow of lubricant towards the rake surface and flushed away the chips from the insert. Therefore, a better lubricating interface has been generated at the chip-tool contact zone with ameliorated penetration of the cutting fluid. Consequently, the friction and cutting force has been reduced. Maximum 55% reduction of cutting force has been achieved using these inserts in combination with MQL supply. Additionally, the flank wear and average surface roughness have been reduced significantly. Moreover, these inserts have participated as chip breaker as well.

Effect of tool flank wear on formation and prediction of tool flank rolling angle using finite element method

The formation and determination of the tool flank rolling angle are discussed in this study. First, the relationship between the tool flank rolling angle and the distribution of the tool wear rate on the tool-flank worn zone is developed by combining the finite element (FE) method and a turning experiment, and the determination method of the tool flank rolling angle using the FE simulation is revealed. Then, the evolution of the tool flank rolling angle with the tool flank wear progress is analyzed, and the evolution of the tool flank rolling angle is also considered in the determination of constants in the Usui model for tool flank wear. Finally, the empirical model of the tool flank rolling angle based on the tool flank wear width VB is proposed based on the FE method. The empirical model results are found to be in good agreement with the experimental results. The evolution of the tool flank rolling angle is considered in tool wear prediction. Compared with the method with a constant tool flank rolling angle, the tool wear prediction accuracy of our model is improved.

Wear prediction of BTA drill based on finite element method for drilling laminated Inconel 625 deposited metal and FeCr alloy material

This study investigated the wear prediction of BTA drills for laminated Inconel 625 deposited metal and FeCr alloy materials using 3D finite element modelling. High interface temperature owing to increased cutting speed enhances the abrasive wear mechanism of Inconel 625, while FeCr alloy exhibits a predominantly adhesive wear mechanism. The interface temperature and normal pressure required as inputs for tool-wear prediction were obtained using response surface methodology (RSM), which was developed by combining the central composite design (CCD) with finite element method simulation. This approach significantly improved the computational efficiency and provides accurate predictions with the calibrated friction model. A modified Usui wear model was established considering the sensitivity of temperature to wear rate for Inconel 625. A significant improvement in prediction accuracy was observed compared with the original Usui equation. The proposed tool-wear prediction model was validated through experimental tests. The maximum predicted flank wear width deviations for the outer and intermediate edges of BTA drill were 2% and 7%, respectively. The results demonstrate the effectiveness of the proposed BTA drill wear-prediction approach for laminated materials with different wear characteristics, providing theoretical guidance for cutting-parameter optimisation and tool-replacement strategies.

Optimization of Dry Turning of Inconel 601 Alloy Based on Surface Roughness, Tool Wear, and Material Removal Rate

In this work, the dry turning of Inconel 601 alloy in a dry environment with PVD-coated cutting inserts was studied. Turning was performed at various cutting speeds, feeds, insert shapes, corner radii, rake angles, and approach angles. After machining, arithmetic mean surface roughness (Ra) and flank wear (VB) were measured, and the material removal rate was also calculated (MRR). An analysis of variance (ANOVA) was performed to determine the effects of the turning input parameters. For the measured values, the turning process was modeled using an artificial neural network (ANN). Based on the obtained model, the process parameters were optimized using a genetic algorithm (GA). The objective function was to simultaneously minimize Ra and VB and maximize MRR. The accuracy of the model and the optimal values were further validated by confirmation experiments. The maximum percentage errors, which are less than 2%, indicate the possibility of practical implementation of the hybrid approach for modeling and optimization of dry turning of Inconel 601 alloy.

Machinability appraisal of nitronic-50 under dry environment using uncoated carbide inserts

ABSTRACT Nitrogen strengthened austenitic stainless steels are uneasy to machine. 22-13-5 stainless steel better known as Nitronic-50 is also not an exception. The current study deals with such an investigation where Nitronic-50 has been machined under varied cutting speeds, feeds and depths of cut and its machinability has been tried to be adjudged on the basis of cutting forces, apparent coefficient of friction, tool-tip temperature, chip reduction coefficient, flank wear width, chip morphology and surface roughness. It is seen that while using higher cutting speed-lower feed-higher depth of cut combination, tangential cutting forces were 18.83% and 29.57%, apparent coefficient of friction was 9.48% and 12.90%, tool-tip temperature was 11.02% and 22.31%, flank wear was 41.25% and 29.91%, and surface roughness was 22.91% and 24.27% lesser as compared to the higher values obtained with higher cutting speed-higher feed-higher depth of cut and intermediate cutting speed-higher feed-higher depth of cut combinations, respectively.

Measurement of flank wear in turning of Monel K500 material based on novel image processing technique

In this article, a novel method for calculating the amount of flank wear that occurs during the turning of the nickel-based superalloy Monel K500 is presented. In order to determine how much flank wear the worn-out insert has sustained, a technique known as the Modified MSER (Maximally Stable Extremal Regions) was applied to it. In this particular piece of research, the algorithm known as the Modified MSER is referred to as the Flank Net. When the data generated by Flank-Net and the flank wear analysed by a tool maker's microscope were compared, an average percentage error of 4.038 percent was found to have been created by Flank-Net. As a result of the strong work-hardening tendency of the Monel K500 and the poor heat conductivity of the material, rapid tool wear has been observed. This has an influence on the dimensional and geometrical precision of the machined products. As a result, research was conducted to investigate the effect that the machining parameters have on tool wear. The experimental trials were navigated with the assistance of the L9 orthogonal array.

Dry machining characteristics of coated inserts and multi response optimization through DEAR‐Taguchi method

AbstractThe primary intent of the proposed research work is to investigate the effectiveness of the titanium aluminium nitride/tungsten carbide‐carbide coated insert during dry turning structural stainless steel. The aim of the study is to simultaneously optimise machining variables like spindle speed, depth of cut and feed for several responses like flank wear, material removal rate and surface roughness. Titanium aluminium nitride/tungsten carbide‐carbide is coated on the surface of carbide tool by cathodic arc evaporation method. The characterization studies have been conducted to ensure the existence of coating material. Micro hardness of coated and pure inserts was tested, which confirms that titanium aluminium nitride/tungsten carbide‐carbide coated insert possesses 17.43 % augmented hardness over pure inserts. The machining was performed by adopting Taguchi experimental design. A multi‐response optimization approach was applied in this study that included ranking methodology based on data development analysis and Taguchi's design. The performance index for multiple responses was measured and mathematically analysed for their effect on processing parameters. The combination of parameter such as spindle speed: 2000 min−1; cutting depth: 0.45 mm and feed rate: 0.16 mm rev−1 was experimental as optimal machining parameters.

Experimental investigation of oxygen as carrier gas in minimum quantity lubrication milling of H11 die steel

Minimum quantity lubrication (MQL) is one of the promising green manufacturing technologies to meet the challenges in the dry machining of hardened die steels. The present work aims to show the effects of various machining environments like dry, MQL with compressed air and MQL with oxygen in the milling of H11 die steel. A biodegradable ester LRT 30 (24cSt at 40 °C) was used as a cutting fluid. The results showed that the MQL with an oxygen-enriched environment provided better results in terms of reduction in cutting force, surface roughness and tool wear. It was also found that the MQL with oxygen was more effective when the cutting velocity ranges between 125 and 150 m/min, as compared with conventional MQL with compressed air. The oxygen enriched MQL helps in retaining the tool's sharpness for a longer period due to the formation of hard oxide layer formation on the tool. The cutting tool under MQL with an oxygen environment removes 40% more material when compared to the conventional MQL with air for the same average flank wear width of 0.3 mm.

Sustainable Dry Machining of Stainless Steel with Microwave-Treated Tungsten Carbide Cutting Tools.

This paper presents a research investigation conducted on the turning of stainless steel 316 material under a dry environment using microwave-treated cutting tool inserts. Plain tungsten carbide WC tool inserts were exposed to microwave treatment for enhancement of their performance characteristics. It was found that a 20-min microwave treatment resulted in the best tool hardness and metallurgical characteristics. These tool inserts have been used to machine SS 316 material following the Taguchi L9 design of experimental techniques. A total of eighteen experiments have been conducted by varying three main machining parameters, i.e., cutting speed, feed rate, and depth of cut, at three levels per parameter. It has been found that tool flank wear increased with all three parameters and surface roughness decreased. At the longest dept of cut, surface roughness increased. An abrasion wear mechanism was found on the tool flank face at a high machining speed and adhesion at low speed. Chips with a helical shape and low serrations have been investigated. Turning SS 316 at optimum machining parameters of 170 m/min cutting speed, 0.2 mm/rev feed rate, and 1 mm depth of cut, as obtained by the multiperformance optimization technique grey relational analysis, resulted in the best values of all machinability indicators: 242.21 µm tool flank wear, 3.81 µm mean roughness depth, and 34,000 mm3/min material removal rate, at a single parameter setting. In terms of research achievements, the percentage reduction in surface roughness is approximately 30% and represents an almost ten-fold improvement in the material removal rate. The combination of machining parameters of 70 m/min cutting speed, 0.1 mm/rev feed rate, and 0.5 mm depth of cut is optimum for the lowest value of tool flank wear when considered for single parameter optimization.

Performance assessment of different cooling conditions in improving the machining and tribological characteristics of additively manufactured AlSi10Mg alloy

Owing to the poor surface characteristics, the AM parts require additional processing, such as machining, polishing, etc. Hence, the present work highlighted the new observations of tool wear and surface integrity aspects in the milling of Laser powder bed fusion produced AlSi10mg alloy under different cooling conditions such as dry, flood, minimum quantity lubrication (MQL) and cryogenic cooling conditions. It was determined that adhesion wear is the primary failure mode observed under milling of AM AlSi10Mg alloy. Flank wear was reduced by 59–63%, 42–45%, and 24–26% under dry, flood, and CO2 conditions, respectively over MQL, which in turn has the effect on surface quality. In addition, it has been noticed that the microstructure has a great effect on the quality of the machined parts and the cryogenic cooling outperformed the MQL cutting method.

Finite element simulation and experimental analysis of B4C‐TiB2‐SiC ceramic cutting tools

AbstractHere, cutting properties and wear mechanism of the home‐made B4C‐TiB2‐SiC ceramic cutting tools in turning of AISI 4340 steel workpieces were studied through a combination of finite element simulation using Deform‐3D software and turning experiments. Simulation results show that cutting parameters have significant effects on the main cutting force and tool temperature of the B4C‐TiB2‐SiC cutting tool. The optimal cutting parameters for the ceramic cutting tool are cutting speed of 300 m/min, depth of cut of .3 mm, and feed rate of .1 mm/r. Experimental results show the cutting length of the B4C‐TiB2‐SiC cutting tool is about 101 m, which is 21.0% and 32.9% larger than that of the home‐made B4C‐TiB2 ceramic cutting tool and commercially available tungsten carbide tool, indicating that the B4C‐TiB2‐SiC cutting tool has a desired service life. The surface roughness of the workpieces processed by the B4C‐TiB2‐SiC cutting tool is 2.43 µm, which is 29.4% lower than that of the workpieces processed by the B4C‐TiB2 cutting tool, indicating that the B4C‐TiB2‐SiC cutting tool has a satisfying machining accuracy. Wear forms of the B4C‐TiB2‐SiC ceramic cutting tool involve craters, chipping, and flank wear, and the main wear mechanisms are abrasive, adhesive, oxidative, and diffusion wear.

Performance evaluation of process parameters using MCDM methods for Titanium Alloy (Ti6al4v) in turning operation

ABSTRACT Titanium alloys are challenging to manufacture because the thin chips create a small surface area between the cutting tool and the workpiece. High cutting temperatures are a result of titanium alloys’ inadequate heat conductivity and excessive stress created by the narrow contact area. This study focuses on the optimisation of the impact on tool life, surface roughness, crater wear, and flank wear. The process variables for turning Ti-6Al-4 V alloy take tool life, surface roughness, crater wear, and flank wear into consideration. Results were analysed using Taguchi-based SAW, VIKOR, TOPSIS, and Electre techniques. The outcomes of the experiment demonstrate that Ti-6Al4V alloy has been successfully turned using CIMCOOL 360 coolant with a 15% concentration. By selecting the best alternative at a cutting speed = 80 rpm, feed rate = 0.18 mm/rev, depth of cut = 0.12 mm, and a rake angle = 14 degrees, where the surface roughness and tool life are, respectively, 0.716 m and 48.3998 min, the research work shows the importance of the suitability of TOPSIS in solving the Multiple Criteria Decision-Making (MCDM). From the ANOVA results, for surface finish, it is noticed that the process parameter rake angle is having Rank 01 for all levels. Thus, the rake angle is the major influencing parameter to achieve a better quality of surface roughness. While in the case of flank wear it is crystal clear that the process parameter DOC is having Rank 01 for all levels. Thus, DOC is the most influencing parameter to achieve lesser flank wear and better quality of tool life.

On the Influence of Binder Material in PCBN Cutting Tools for Turning Operations of Inconel 718

Inconel 718 is a highly valued material in the aerospace and nuclear industries due to the fact of its exceptional properties. However, the processing of this material is quite difficult, especially through machining processes. Machining this material results in rapid tool wear, even when low material removal rates are considered. In this study, instrumented turning experiments were employed to evaluate the machinability of Inconel 718 alloy using PCBN tools while assessing the usage of two distinct binder phases, TiN and TiC, for those cutting tools. It was found that the tool life was highly sensitive to the cutting speeds but also affected by the workpiece mechanical properties. At lower cutting speeds, notch wear significantly impacted the tool integrity, whereas at higher cutting speeds, flank wear was the primary failure mode of the tool. The flank wear of the tools with TiN-based binder outperformed TiC by almost 30%, presenting a more consistent behavior when machining.

An adaptive method of measuring the rake face wear of end mills based on image feature point set registration

An acceptable tool wear evaluation and acquisition approach is critical for developing an accurate, rapid, and practical online tool wear prediction system. The one-dimensional crater wear depth is difficult to quantify, and relying solely on flank wear width is very simplistic. External conditions such as vibration and illumination have a large impact on two-dimensional wear area and three-dimensional volume. In practice, these are difficult to successfully characterize tool wear. This work proposes a two-dimensional rake face edge loss area as an additional indicator to assess milling cutter wear. An adaptive measurement approach based on 2D image feature point set matching is presented to suppress the area calculation error caused by image position offset and chips or built-up edges. 201 images were collected in two groups of cutting experiments for comparison with the proposed method and the other two methods, manual registration and non-registration. The results show that the proposed method's measurement values are closer to the actual values and have a higher measurement efficiency. Furthermore, the proposed indicator is sensitive to micro-scale changes to the blade edge, especially at the tip, and can be used as a supplement one to monitor tool wear more comprehensively.

A fundamental approach to determine the impact of aramid and carbon fibers on durability and tribological performance of different polymer composites demonstrated in gear transmission process

Abstract When selecting a polymer or a reinforced polymer material for a specific drive technology, it is crucial to have a comprehensive understanding of the component’s operating characteristics, including the mechanics of tribological contact and the fatigue life of the materials used in gears. The choice of material plays a pivotal role in the gear running process, as it induces heat generation in the meshing zone and triggers flank wear progression along the high points of the teeth, which directly impacts the gear’s lifetime. This paper presents the results of durability testing conducted on steel/polymer gear pairs. The tested polymer materials were based on polyacetal and polyamide 66 chemical bases, reinforced with aramid, carbon fibers, and internally lubricated with polytetrafluoroethylene. The aim of the study was to evaluate the durability and thermal response of the materials and determine their correlation with flank wear rate progression. The results indicate that gears produced from polyacetal, and carbon-reinforced polyamide 66 materials exhibit the longest durability. Notably, the generated meshing temperatures are closely connected with flank wear propagation. The lowest wear coefficients were observed in gears produced from polyacetal and polyamide 66 materials reinforced with carbon fibers.

Towards understanding the wear mechanisms of turning with FreeTurn

For many years, tool wear has been a critical issue with respect to productivity, cost, and part quality, particularly for superalloy machining. The underlying wear mechanisms of a new turning tool, FreeTurn, is revealed in this paper towards its potential for a more sustainable way of metal cutting. It is a specially designed turning tool that is held by the tool spindle and has a working plane perpendicular to the centreline of the tool spindle, making it rotatable on its working plane. Owing to the unique feature of FreeTurn compared with conventional turning tools, the focus of this study is on the effect of dynamic tool–workpiece engagement on tool wear. The tool path strategy is first set to achieve a cylindrical surface in longitudinal turning with a rotatable FreeTurn tool. Series of experiments with different tool path strategies are performed on a turn–milling machine, using Inconel 718 as an example of workpiece material. The results indicate that the coupling effect between notch and flank wear is the decisive factor of tool wear in free turning with respect to its rotation and feeding directions. While the tool wear can be significantly reduced if the tool feeds with increasing cutting edge angle, the tool will soon be worn out if it feeds with decreasing cutting edge angle. Tool rotation in free turning plays a key role in reducing adhesion on the cutting tool and increasing the tool rotation speed can further improve this effect. Additionally, a more sustainable solution that uses both sides of the cutting edge becomes possible with FreeTurn as well, improving the tool utilisation. The results demonstrate considerable guiding significance for exploring the potential of this new turning tool towards a longer tool life.

Cutting performance and surface quality of Ti-6Al-4V by longitudinal ultrasonic vibration-assisted high-speed dry milling with coated carbide tools

Longitudinal ultrasonic vibration-assisted high-speed dry milling (LUVAHSDM) is adopted to improve the cutting performance and surface quality of Ti-6Al-4V (TC4). Multifaceted comparisons are presented in terms of milling force, milling temperature, tool wear, 3D surface roughness, and residual stress, utilizing AlCrN, AlCrSiN, AlTiN, and AlTiSiN-coated tools. The results show that the maximum milling forces in the feed and longitudinal directions both decreased at first and then increased with the increasing of Al element contents, during which the single edge and average flank wear increased. Therefore, the surface roughness of TC4 becomes more uniform using AlTiN-coated tools, and the residual stress is significantly reduced to 98.57 MPa. Combining the results of milling force, milling temperature, tool wear, 3D surface roughness and residual stress data, it is found that AITiN-coated tools achieve excellent cutting performance and surface quality. The excellent machining performance of coated carbide tools demonstrates the feasibility and effectiveness of applying LUVAHSDM methods.