Improve Tool Life Research Articles

Tool life improvement for stamping dies in the coining process

ABSTRACT High temperature and high-speed pressing in minting operations lead to the failure of coin-stamping dies. As a result, new coining tools were required more frequently leading to lower operational productivity and higher production costs. This research has examined the effects of materials and surface coating selections on the tool life of the stamping dies in the coining process. The aim of this research was to explore the possibility of extending the tool life of stamping dies. The three kinds of materials under study were alloy tool steel, cold working tool steel, and hot working tool steel. Additionally, Titanium Nitride (TiN) and Chromium Nitride (CrN) surface coating materials using the Physical Vapour Deposition (PVD) process were investigated. The experiment results revealed that the hot working steel yielded the highest tool life of up to 1,300,000 coins, followed by cold working steel at 900,000 coins, and alloy tool steel at 600,000 coins. The CrN PVD coating provided up to more than 400,000 coins compared to TiN PVD coating on hot working tool steel.

Machinability Performance of Single Coated and Multicoated Carbide Tools During Turning Ti6Al4V Alloy

AbstractThis paper presents the machinability performance of uncoated, single-coated, and multicoated carbide tools during turning of Grade 5 (Ti6Al4V) Titanium alloy, which is challenging to machine due to its distinctive material properties. Coated tools with single-coated Titanium Aluminium Nitride (TiAlN) and multi-coated layer of Titanium Aluminium Nitride with Aluminium Chromium Nitride (TiAlN + AlCrN) coated inserts were utilized to assess surface roughness (Ra), tool wear rate (R), and chip morphologies under various cutting conditions using dry machining. Analysis of the used tools revealed that coated tools exhibited improved tool life and surface quality compared to uncoated tools across all cutting conditions. Multi-coated tools of TiAlN + AlCrN demonstrated a tool life increase of up to 15% compared to uncoated and single-coated tools, with surface roughness improvements ranging from 30 to 45% depending on cutting speed. Chip morphology analysis indicated an increase in the chip reduction coefficient with higher cutting speeds for all tool types. Coated tools exhibited the lowest chip-reduction coefficient due to the presence of TiAlN and AlCrN coatings, which control the tool chip contact length. Conversely, uncoated chip morphology resulted in larger chip thickness values compared to coated tools, particularly at cutting speeds above 100 m/min, attributed to poor heat dissipation and chemical reactions at the tool chip interface. Energy dispersive X-ray scanning electron microscopy (SEM/EDXS) analysis of worn uncoated inserts revealed a higher tendency towards Titanium adhesion compared to coated tools. The proposed multi-layer coatings of (TiAlN + AlCrN) used for dry machining proved highly beneficial for achieving economic machining objectives and may reduce the need for lubrication when processing Ti6Al4V alloys.

Effect of Deposition Parameters on Micromechanical Properties and Machining Performance of CrN Coating for Wet Finish Turning of Ti6Al4V Alloy.

This study aims to optimize the performance of CrN coatings deposited on WC cutting tools for machining Ti6Al4V alloy, where the formation of built-up edge (BUE) is a prevalent and critical issue. In-house CrN coatings were developed using the PVD (Physical Vapor Deposition) process, with variations in deposition parameters including nitrogen gas pressure, bias voltage, and coating thickness. A comprehensive experimental approach encompassing deposition, characterization, and machining performance evaluation was employed to identify the optimal deposition conditions. The results indicated that CrN coatings deposited at a nitrogen gas pressure of 4 Pa, a bias voltage of -50 V, and a thickness of 1.81 µm exhibited superior performance, significantly reducing BUE formation and tool wear. These optimized coatings demonstrated enhanced properties, such as a higher elastic modulus and a lower coefficient of friction, which contributed to improved tool life and machining performance. Comparative studies with commercial CrN coatings revealed that the in-house developed coatings outperformed the commercial variants by approximately 65% in tool life, owing to their superior mechanical properties and reduced friction. This research highlights the potential of tailored CrN coatings for advanced machining applications and emphasizes the importance of optimizing deposition parameters to achieve high-performance tool coatings.

The Impact of the Radius of the Cutting Blade during the Processing of C 60 ± 2 HRC (DIN) Steel

This study investigates the thermal dynamics of the turning process for C60 steel, focusing on the influence of various machining parameters on temperature rise. Integrating experimental methods and statistical analysis, the research examines the effects of cutting speed (v), feed rate (f), depth of cut (a), and cutting insert tip radius (r) on the average temperature in the cutting zone. Experiments were conducted on heat-treated C60 steel rings, using a custom fixture and a modified Kennametal insert holder to ensure precise temperature measurements, collected via a natural thermocouple method. The findings reveal that cutting speed is the most significant factor influencing temperature rise, followed by feed rate, while depth of cut has a minor impact. Notably, the radius of the cutting insert tip is inversely proportional to the temperature, with an increase in the tip radius resulting in a decrease in average temperature. This inverse relationship underscores the potential for optimizing tool design to enhance heat dissipation and reduce thermal stress on the cutting tool. A fourth-degree polynomial model was developed through regression analysis to correlate thermovoltage (V) with temperature (T), providing a quantitative framework for predicting thermal behavior. The model highlights that cutting speed has the greatest effect on temperature rise, with the highest recorded temperature being 795.09°C. Conversely, larger radius of the cutting insert tip corresponds to lower average temperatures, stabilizing around 757.22°C. These insights offer actionable strategies for optimizing machining processes. By strategically adjusting cutting parameters, particularly cutting speed and feed rate, manufacturers can achieve significant improvements in tool life and product quality. The developed mathematical model serves as a predictive tool for fine-tuning machining conditions, ensuring a balance between productivity and tool longevity. This research contributes substantially to the understanding of thermal dynamics in machining processes. It provides a comprehensive analysis and robust modeling of the effects of cutting parameters on temperature rise, supported by rigorous experimental data and statistical validation. The study underscores the importance of considering thermal effects in machining to optimize efficiency, tool life, and product quality, offering valuable insights for both academic research and practical applications in the field of machining and process optimization.

Research on the Application of Superhard Coating Technology for Cutting Tools in Mechanical Processing

The superhard coating technology for cutting tools has important applications in the field of mechanical processing. This article introduces the development of superhard coating materials for cutting tools, including low-pressure gas-phase synthesis of diamond, cubic boron nitride, and physical vapor deposition (PVD) coating technology. The superhard coating of cutting tools is widely used in turning, milling, tapping, key component machining, high-speed steel drill bits and taps. Research has shown that coatings can reduce cutting forces and improve tool life, but attention should be paid to residual compressive stress. The future development direction includes researching new superhard material cutting tools and developing coating methods that are more wear-resistant and have high temperature hardness.

Investigation of different abrasive jet machining methods applied to milling tool coatings for post-treatment

Post-processing of tool coatings is an essential way to remove defects, enhance coating properties, and improve tool performance, where abrasive jet machining plays an important role. This paper introduces a novel application of self-developed elastic abrasives to the post-treatment of coated tools, with a comparison against hard abrasive (Al2O3) jet machining (HAJM). The results demonstrate that EAJM significantly reduces the surface roughness of the coating and enhances the wear resistance of milling tools across a wide range of jetting parameters without damaging the coating. Conversely, HAJM yields more pronounced improvements in physical properties such as coating hardness, elastic modulus, and residual stress, and also significantly enhances tool performance, albeit with a need for precise process parameters. Overly aggressive HAJM parameters can lead to diminished coating performance and reduced tool life. Additionally, the study reveals that the improvement in tool life is closely linked to the physical properties of the coating, which contributes to the enhanced performance observed with HAJM-treated tools. To further investigate this, a mathematical model was established to analyze the coupling effect of jet pressure and time on tool life. The proposed model identifies the optimal ranges of the jetting coefficient for HAJM and EAJM as 326–4870 kPa·s and 1061–17,780 kPa·s, respectively, offering a novel approach to optimizing tool performance and life.

Machinability improvement by in-operando Tool Protection Layers through designed steel alloying: The case of manganese steel

Improvements in machinability by alloying of the workpiece often adversely impact the end user properties of a material. For example, the common use of non-metallic inclusions can lead to improved tool life during turning or milling, but often adversely affects weldability, corrosion, and wear resistance. A cutting tool material meets kilometers of workpiece material during a machining operation. Hence elements in small quantities in the workpiece may insignificantly affect the end user properties but may have large effects on tool wear. One such effect is the formation of refractory and wear resistant reaction products between the workpiece and tool. Such reaction products forming on tool surfaces may lead to improved machinability. This paper proposes the use of small amounts of alloying to induce such a Tool Protection Layer. Additionally, the paper develops a computational framework for designed alloying which balances formation of Tool Protection Layers, its in-process retention, and the functional properties of the alloy. The method has been validated for a case of manganese steel. The calculations were validated first by a wide range of diffusion experiments. Then by industrial turning of cast alloys, by comparing one reference and two newly designed alloys based on the alloying concept. The alloy with 0.003 mol fractions of Al resulted in more than 3 times increase in tool life, due to in-operando formation of Al2O3 Tool Protection Layer. The designed manganese steel maintained its functional properties with respect to abrasive wear resistance and retained its ability to work harden.

Experimental investigation into machining performance of magnesium alloy AZ91D under dry, minimum quantity lubrication, and nano minimum quantity lubrication environments

Abstract Due to its low density, magnesium is recognized as a lighter metal and it is favorable for frequent use in industries. It is used in aerospace, biomedical, automotive, and other industrial applications. Magnesium is a promising element that is vital for reducing emissions, improving efficiency, protecting the environment, and enhancing the machine economy. This study analyzes the influence of various cutting environments and parameters on the turning operation of magnesium base alloy (AZ91D). Aluminum 9% and Zinc 1% is the main constituent of AZ91D. The machining process was accomplished using dry, minimum quantity lubrication (MQL), and nano minimum quantity lubrication (NMQL) environments based on their influence on surface roughness (SR) and temperature. Under certain circumstances, it was observed that SR decreases with the increase in the cutting velocity (V c), feed rate, and depth of cut. During cutting of AZ91D in dry conditions, it is preferred to use a moderate speed. Higher temperature was recorded during dry conditions which can significantly reduce the life span of the tool. MQL and NMQL have reduced the cutting temperature by a margin of 25–40% compared to dry machining, thus improving tool life. NMQL has shown decent cooling results compared to other cooling systems.

Experimental and numerical studies on the flank wear during the thread milling; Effect of infeed strategies in different cutting speeds

Thread milling is an alternative to tapping in which tool wear is one of the main limitations. Infeed strategies significantly affect tool wear, which has not been studied in previous investigations. Hence, current research studies the effect of infeed strategies (radial, modified flank, and incremental) on flank wear during thread milling considering different cutting speeds. According to FEM simulations, the incremental method led to the minimum tool temperature and the highest cutting length (tool life). According to experimental results, incremental and modified flank infeed methods improved tool life up to 340 % and 80 %, respectively compared to the radial infeed method in cutting speed of 48 m/min. Also, the incremental infeed method was superior in higher cutting speeds.

Machinability improvement in micro milling AlN after laser chemical milling

Processing microchannels inside laminated aluminum nitride high-temperature co-fired ceramics (AlN HTCC) packaging, a typical difficult-to-cut ceramic, can effectively solve the heat-dissipation problem of integrated chips used in smart skin. In order to improve the processing efficiency and quality of AlN, the machinability of AlN after laser chemical milling (LCM) was studied through the milling force, machined surface quality, surface defects, formation mechanism, and tool wear. This study established a milling force model that can predict the milling forces of AlN and analyses the reasons for the improvements in the milling force based on experimental data and predicted data. The results from the model and experiments demonstrated that the milling force of the laser chemical milling assisted micro milling (LCAMM) decreased by 85%–90% and 85%–95%, respectively, due to the amount of removal of a single edge was more uniform and the actual inclination angle increased during the cutting process in LCAMM. Moreover, the machined surface quality improved by 65%–76% after LCM because of less tool wear, fewer downward-propagating cracks generated during each feed, and the surface removal mode transformed from intergranular fracture to transgranular fracture, which effectively reducing tool wear and improving tool life. Finally, when feed per tooth and depth of cut were 0.4 μm/z and 5 μm, the optimal machined surface quality was obtained, with a roughness of 64.6 nm Therefore, milling after LCM can improve the machinability of AlN and providing a feasibility for the high-quality and efficient machining of microchannels.

Research on drilling performance and tool life improvement methods of titanium alloy ultra-high-speed drilling bits

Research on drilling performance and tool life improvement methods of titanium alloy ultra-high-speed drilling bits

Machining of Ni-based superalloys using CAPVD coated carbide tools

The ever-increasing demand for cost-effective machining of Ni (Nickel) based superalloys has made it necessary to explore nanocomposite coatings as a potential surface engineering solution. The present study aims to investigate the variation in machining performance of new-generation hard wear-resistant coatings in milling of IN 718 (Inconel 718), IN 625 (Inconel 625), and IN 617 (Inconel 617). TiAlSiN and CrAlSiN coatings were grown in-house over tungsten carbide (WC) milling inserts through the cathodic-arc PVD route. The TiAlSiN coating improved the tool life by 80 % and 60 % in the case of IN 718 and IN 625, respectively. However, in the case of IN 617, the TiAlSiN-coated tool could not even reach the uncoated tool life. The CrAlSiN coating, on the other hand, improved the tool life by more than 200 % in the milling of IN 617. Tool-chipping was the dominant failure mode among all observed, which included flank wear and workpiece adhesion. The repeated adhesion and removal of the workpiece layer from the tool surface was a major cause of tool failure. The coating layer delayed the initiation of the chipping and prolonged the flank-wear-dominated machining time, resulting in improved tool life. The wear resistance of coatings in machining different workpiece materials was greatly influenced by the relative affinity of constituting elements of workpieces for employed coatings. The machining chips exhibited shear bands and saw-tooth (serrated/segmented) morphology in almost all cases. The degree of segmentation showed a direct correlation with tool life. The present work helps identify the optimum coating and machining conditions for three different grades of Ni-based superalloys. Additionally, the underlying mechanisms were analyzed and discussed with scientific observations.

Iron ion detection and life cycle assessment of cutting fluid based on photoluminescent nitrogen-doped carbon quantum dots

Cutting fluid (CF) ensures machining accuracy and improves tool life in machining, which is of great significance for its impurity content detection and life cycle evaluation. In this paper, citric acid and arginine were used as carbon and nitrogen sources, photoluminescent (PL) nitrogen-doped carbon quantum dots (N-CDs) with a particle size ranging from 8 to 14 nm and well dispersion in water-based CF were synthesized by a one-pot hydrothermal reaction method. The N-CDs have the best signal under 360 nm ultraviolet light excitation, which well avoids the autofluorescence of the CF. The N-CDs dispersion have good selectivity and linearity in the Fe3+ concentration range of 2 to 80 μM, and the detection limit is 1.2 μM. The N-CDs were used to detect the concentration of Fe3+ in CF with different working hours, and the results were consistent with the results of coupled plasma emission spectroscopy. This study provides an intelligent sensing platform for the highly sensitive and selective detection of Fe3+ in the CF environment, and provides a promising strategy for the evaluation of the CF lifetime.

Influence of bond thermal and mechanical properties on the additively manufactured grinding wheels performance: Mechanical, wear, surface integrity, and topography analysis

It is always a great challenge to fabricate customized grinding wheels using diverse bonding materials to determine their impacts on the cutting ability and grinding performance. Additive Manufacturing methods offer tremendous advantages for customized and prototype production to reduce the cost as well as increase speed to market. This work aims to extend the grinding operation knowledge by examining acrylate base resin bonds with different mechanical and thermal characteristics to print the grinding wheels. Extensive experiments are conducted to investigate their performance in metal grinding, with hardness ranging from soft to super hard. A remarkable improvement in grinding performance has been established by using high-temperature resistance bond material, which was more prominent in the case of aluminium and hardened steel. It was discovered that utilizing the bond material with a higher mechanical and thermal characteristic could provide high grain retention under elevated temperatures, which participated in less grinding force (up to 58 % and 18 % in the case of soft and hard metals, respectively). Employing bond material with improved mechanical and thermal properties to fabricate grinding wheels significantly prolonged the tool life, for example, by up to 80 % for hardened steel at maximum, along with promoting dimensional accuracy. Nevertheless, however, using high-temperature resistance resin brought slight improvement in tool life for the hard metals grinding due to the intensely aggressive grinding condition, which could not be largely compensated by using modified resin. The surface roughness of the ground part represented considerable improvements through using high-temperature resistance resin by representing 33 % and 30 % roughness values reduction for Al and hard metal, respectively, compared to those ground with lower temperature resistance resin. Moreover, the ground surface's microhardness examination indicated meaningful surface microstructure change by applying different grinding parameters and bond material types. Furthermore, the microtopography of the grinding wheels before and after the grinding operation revealed that employing the higher temperature resistance resin could bring about notably less chip loading and grain loss.

Assessment of cutting tool wear using a numerical FEM simulation model

The advancement of computational modeling techniques, such as FEM, has allowed to simulate complex machining processes with improved accuracy. Wear prediction is a crucial aspect in understanding and optimizing machining processes, as it directly impacts tool life, surface quality and overall machining efficiency. This work focuses on the FEM simulation, specially utilizing the DEFORM software, in conjunction with the Usui wear model, for wear prediction in machining operations. The Usui wear model, a well-established and widely used wear prediction approach, accounts for multiple wear mechanisms that include adhesion, abrasion, and diffusion. By incorporating the Usui wear model into the FEM simulation framework within the DEFORM software, it is possible to understand wear phenomena in machining processes. The integration of Usui wear model algorithms into DEFORM enables the simulation to accurately predict wear rates, distribution patterns, and progression of tool deterioration. This predictive capability facilitates the identification of critical wear zones and guides proactive measures to improve tool life, reduce production costs, and optimize machining productivity. This work presents research focused on wear prediction in cutting processes, utilizing FEM simulation with DEFORM software and incorporating the Usui wear model. Through a comprehensive analysis of wear phenomena, this research aims to optimize cutting parameters, improve tool life, and contribute to the advancement of machining and manufacturing technologies.

ANALYSIS OF CUTTING FLUID ON MASS LOSS OF CARBIDE INSERT IN THE MILLING PROCESS

The Machining process is manufacturing in the world industry that is widely used. The coolant in the machining process functions to lower the temperature and lubricate and clean the gram in the cutting process. The application of coolant in the cutting process is to maintain the quality of the workpiece during the cutting process and also serves to improve tool life so that the tool does not wear out easily. This study aims to determine the effect of a chemical-based coolant based on dromus oil and vegetable CPO on tool wear in the face milling process and to determine whether or not the liquid is effective in reducing and slowing down tool wear. In this research, the face milling process used a grey cast iron specimen as the workpiece specimen used and also used a carbide insert chisel cutting tool with the TPKN 22 VC2 type. The research was carried out by varying the engine speed and also the coolant variation, the engine speed variations used were 80, 360 and 720 Rpm. In the process of administering coolant using the method, it is sprayed directly onto the workpiece area which is cut continuously, in the milling process with a response variable that can be in the form of data or tool wear values that have been observed and tested using a microscope test tool, using the weight (mass) method to see the wear value. This research aims to see how effective the use of vegetable- based coolant (CPO) during experiments as a coolant in the machining process aims to ensure that the final value of tool insert wear must be smaller with (CPO) compared to chemical coolant (dromus).

Impact of cryogenic treatment on the performance of coated tungsten carbide inserts during machining of EN24 grade alloy steel

AbstractToday's industries need to be more productive, especially those that shape and machine materials. As a result, engineers and scientists are seeking for cutting tool materials and technologies that have high hot hardness, chemical stability, wear resistance, and toughness while also improving tool life or contact time. Cryogenic treatment of cutting tools has been proven to be a good way for increasing the contact time of any cutting tool material. This study presents the results of turning alloy steel (EN24 grade) using P20 grade carbide inserts under various conditions under continuous machining. Cutting speeds varied from 100 to 500 m/min (in increments of 100 m/min), with feed rates ranging from 0.1 to 0.4 mm/rev in stages of 0.1 mm/rev and a constant radial depth of cut of 1.5 mm were considered under dry machining conditions. Cryogenic treated/coated inserts are better than other inserts in terms of tool life for optimized parameters such as cutting speed 100 m/min, feed rate 0.1 mm/rev, and depth of cut 1.5 mm, according to the study's findings. Under similar conditions of cutting speed, feed rate, and depth of cut, coated/cryotreated inserts had a tool life increase of about 97.5% over uncoated/untreated inserts, a 50.58% increase over uncoated/crytreated inserts, and a 23.89% increase over coated and untreated inserts, respectively.

Wear mechanisms in Ti(C,N)-Al2O3 coated carbide during sustainable machining CGI

By replacing conventional gray cast iron (GI) with compacted graphite iron (CGI), automotive industry could keep up with stricter regulations on emissions and demands on higher engine performance. CGI has improved properties as to GI but is more difficult to machine. This study evaluates sustainable machining performance during finish face milling when using minimum quantity lubrication applied vegetable oil, resulting in 8% or 17–23% improved tool life respectively as to dry conditions. The main part of the study investigates the wear mechanisms in commercial Ti(C,N)-Al2O3 CVD-coated cemented carbide. The coating degrades by mechanically induced cracking and fractures, oxidation of adhered CGI inside cracks, diffusional dissolution of Ti(C,N) layer. Formation of softer (Mg,Fe,Mn)Al2O4 spinel is not observed but could be an expected reaction product. Other oxide inclusions, when deposited on cemented carbide surfaces, prevents adhesion of CGI material, and can reduce the wear rate where they are present. CGI adhering to cemented carbide induces diffusional loss of cobalt and carbon that eventually forms (Fex,Co1-x)3C iron carbide at the tool-workpiece interface which can reduce the diffusion rate. Novel findings also relates to the formation of 15 μm deep cracks in the cemented carbide due to inward diffusion of Fe accompanied by its oxidation that speeds up the oxygen ingress and further oxidation of W and Co. Oxidation was found to provide a positive effect when the adhered CGI completely oxidized to form Fe2SiO4 oxide ceramic Tool Protection Layer which slowed down tool material degradation.

Effect of noble gases ion implantation on the life time of WC-Co tools usedin wood-based material machining

Effect of noble gases ion implantation on the life time of WC-Co tools used in wood-based materialmachining. The results of the investigations on the tool life of WC-Co tools, implanted with three noble gas ions,i.e. helium, neon and argon, are presented in the comparison with the virgin tools and tools implanted withnitrogen ions. The surface modification of the tools was preceded by the modelling of the depth profiles of theimplanted elements. The implantation of the ions of noble gases resulted in an improvement in tool tool life, inthe range from 5 to 49%.

Identification of tool wear and surface morphology measurements in sustainable milling of Al 6082 hybrid metal matrix composite

Aluminium hybrid metal matrix composites have significantly increased in many advanced applications owing to their unique properties. However, these hybrid composites are difficult to machine because of hard reinforcements in the matrix. After identifying the optimum cutting conditions, it's crucial to identify the tool wear mechanisms to keep surface roughness within the desired range, especially with hybrid composites. Hence, the present work mainly focuses on identifying the wear mechanism of PVD-coated TiAlN cutting tool inserts during the end milling of Al 6082 hybrid metal matrix composites. MQL, CO2, and a combination of MQL + CO2 cooling conditions were employed over the cutting zone to decrease tool wear. In the context of 300 mm of cutting length, employing CO2, MQL, and MQL + CO2 conditions led to a significant reduction in tool wear by 34.5 %, 50.1 %, and 74.7 %, respectively, compared to dry cutting. The results showed that the MQL + CO2 condition produced better results than the other cooling conditions, improving tool life and surface quality.