TiAlN Coated Carbide Tool Research Articles

Research on Coated Tool Life and Wear in Ta-2.5W Alloy Turning.

Due to its inherent high hardness, strength, and plasticity, tantalum-tungsten (Ta-W) alloy poses a considerable challenge in machining, resulting in pronounced tool wear, diminished tool lifespan, and suboptimal surface quality. This study undertook experiments utilizing uncoated carbide tools, TiAlN-coated carbide tools, and AlTiN-coated carbide tools for machining Ta-2.5W alloy. The investigation delved into the intricacies of surface temperature, tool longevity, and the distinctive wear characteristics under varying coating materials and cutting parameters. Concurrently, a comprehensive exploration of the wear mechanisms affecting the tools was conducted. Among the observed wear modes, flank wear emerged as the predominant issue for turning tools. Across all three tool types, adhesive wear and diffusion wear were identified as the principal wear mechanisms, with the TiAlN-coated tools displaying a reduced level of wear compared to their AlTiN-coated counterparts. The experimental findings conclusively revealed that TiAlN-coated carbide tools exhibited an extended tool lifespan in comparison to uncoated carbide tools and AlTiN-coated carbide tools, signifying superior cutting performance.

Полуэмпирическое моделирование температуры резания и шероховатости поверхности при точении конструкционных материалов твердосплавным инструментом с покрытием TiAlN

Introduction. In manufacturing, obtaining a specified surface roughness of the machined components is of great importance to fulfill functional requirements. However, this is significantly affected by the heat generated during processing, potentially causing variations in dimensional accuracy. The surface roughness significantly affects the fatigue performance of the component, while the cutting tool's lifespan is dictated by the generation of cutting temperatures. The purpose of the study is to create semi-empirical models for predicting surface roughness and temperature of different work materials. Improved cutting performance is achieved by precisely determining the cutting temperature in the zone being machined. However, calculating the cutting temperature for each specific case is fraught with difficulties in terms of labor resources and financial investments. This paper presents a comprehensive empirical formula designed to predict both theoretical temperature and surface roughness. The methodology. The surface roughness and temperature values were evaluated for EN 8, Al 380, SS 316 and SAE 8620 materials using TiAlN coated carbide tool. The TiAlN coating was formed using Physical Vapor Deposition (PVD) Technique. The response surface methodology was used to prepare predictive models. Cutting speed (140 to 340 m/min), feed (0.08 to 0.24 mm/rev) and depth of cut (0.6 to 1.0 mm) was used as input parameters for measuring the performance of all material in terms of surface roughness and cutting temperature. The tool-work thermocouple principle was used to measure the temperature at the chip-tool interface. A Novel Calibration Setup was developed to establish a connection between the electromotive force (EMF) generated during machining and the cutting temperature. Results and Discussion. It is observed that the power required for machining was largely transformed into heat. The highest cutting temperature is recorded when machining of SS 316 followed by SAE 8620, EN 8. However, low temperature is reported during machining of Al 380 and it is mainly governed by the thermal conductivity of the material. The lowest surface roughness is observed in SAE 8620, EN 8 material followed by SS 316 and Al 380. Semi-empirical method and regression model equations show a good agreement with each other. Statistical analysis of nonlinear estimation reveals that the cutting speed, feed, and density of the material have a greater effect on surface roughness, whereas the depth of cut has a greater effect on temperature generation. The study will be very useful for predicting industrial productivity when machining of EN 8, Al 380, SS 316 and SAE 8620 materials with TiAlN-coated carbide tool.

Cutting Performance and Tool Wear of AlCrN- and TiAlN-Coated Carbide Tools during Milling of Tantalum–Tungsten Alloy

Tantalum–tungsten alloys have been widely used in different industrial sectors—for example, in chemical, medical, aerospace, and military equipment. However, they are usually difficult to cut because of the large cutting force, rapid tool wear, and poor surface finish during machining. This paper presents the machining performance and cutting tool wear of AlCrN/TiAlN-coated carbide tools during the milling process of Ta-2.5W. The effects of cutting parameters on the cutting forces and surface roughness of AlCrN/TiAlN-coated carbide tools were obtained and analyzed. The results show that the wear resistance of AlCrN-coated tools is better than that of TiAlN-coated tools, and that the main wear mechanisms of both cutting tools are crater wear, adhesive wear, and diffusion wear. Compared to TiAlN-coated tools, AlCrN-coated tools reduced the cutting forces by 1% to 15% and decreased the surface roughness by 6% to 20%. A cutting speed within the range of 80–120 m/min can ensure a low cutting force while maintaining good surface roughness, which is more conducive to machining Ta-2.5W.

Effect of milling parameters on machinability of SA508-3 steel in high-speed milling with uncoated and coated carbide tools

SA508-3 steel is popularly used to produce core unit of nuclear power reactors due to its outstanding ability of anti-neutron irradiation and good fracture toughness. Additive forging is a new technology for manufacturing SA508-3 steel forgings. However, the production efficiency and interface bonding quality of heavy forgings are respectively limited by the processing efficiency and surface quality of substrates in the additive forging process. High-speed milling technology is an effective method for improving machining efficiency and quality. Unfortunately, only a few studies on the milling of SA508-3 steel have been reported. In this study, we studied high-speed milling of SA508-3 steel and compared the cutting performances of uncoated, titanium aluminum nitride (TiAlN)-coated, and Al2O3-coated carbide tools. The tool life and cutting force were evaluated using various milling parameters under dry milling conditions. The wear modes and mechanisms were also investigated. The results show that adhesive wear occurs more frequently in the uncoated carbide tool, whereas coating flaking is predominant in the Al2O3- and TiAlN-coated carbide tools. Furthermore, the Al2O3-coated carbide tool showed better cutting performance than the TiAlN-coated and uncoated carbide tools considering the tool life and surface quality. The tool life of the Al2O3-coated carbide tool reached 200 min and the removed workpiece material was 182 × 103 mm3 under the blunt tool criteria. The study of tool life and wear behavior based on the practical cutting experiments contribute to the improvement of the milling quality and provides a theoretical basis for tool material selection and process optimization in milling SA508-3 steel.

A new approach of measurement and analysis of PVD - TiAlN coated carbide tools in machining of Monel 400 alloy under hybrid cooling conditions

This research work focuses on the efficacy of minimum quantity lubrication (MQL) and cryogenic carbon dioxide (CO2) cooling in high-speed machining of nickel-based alloy. CO2 and MQL supplied in the rake face were compared to CO2 and MQL in turning of Monel 400. Tool wear, temperature, surface roughness, and microstructural assessments were done to compute the cooling influence of distinct approaches. Energy dispersive spectrometry (EDS) mapping is employed to investigate the abrasion and adhesion mechanisms. The wear levels were reduced under the use of the hybrid approach; the decrease in flank wear value relative to the hybrid condition is 78%, 36%, and 27%, and in terms of crater wear, the reduction was 78%, 54%, and 48% over dry, MQL, and cryo CO2 conditions, respectively. Findings have portrayed that the lessening of temperature at the cutting area with the hybrid condition reduces the roughness by 58%, 44%, and 20% over dry, MQL, and cryo CO2 cutting strategies, respectively. Moreover, verdicts of the investigation confirm smaller grain size and high hardness under cryo cooling condition.

Comparison of Surface Morphology and Tool Wear in the Machining of Ti-6Al-4V Alloys with Uncoated and TiAlN Tools under Dry, Minimum Quantity Lubrication, Flood Cooling, and Low-Temperature Spray Jet Cooling Conditions.

TiAlN-coated carbide tools have been used to machine Ti-6Al-4V alloys in aviation workshops. However, the effect of TiAlN coating on surface morphology and tool wear in the processing of Ti-6Al-4V alloys under various cooling conditions has not been reported in the public published literature. In our current research, turning experiments of Ti-6Al-4V with uncoated and TiAlN tools under dry, MQL, flood cooling, and cryogenic spray jet cooling conditions were carried out. The machined surface roughness and tool life were selected as the two main quantitative indexes for estimating the effects of TiAlN coating on the cutting performance of Ti-6Al-4V under various cooling conditions. The results showed that TiAlN coating makes it hard to improve the machined surface roughness and tool wear of a cutting titanium alloy at a low speed of 75 m/min compared to that achieved by uncoated tools. The TiAlN tools presented excellent tool life in turning Ti-6Al-4V at a high speed of 150 m/min compared to that achieved by uncoated tools. From the perspective of obtaining finished surface roughness and superior tool life in high-speed turning Ti-6Al-4V, the selection of TiAlN tools is feasible and reasonable under the cryogenic spray jet cooling condition. The dedicative results and conclusions of this research could guide the optimized selection of cutting tools in machining Ti-6Al-4V for the aviation industry.

The effect of chip formation on the cutting force and tool wear in high-speed milling Inconel 718

Coated carbide tools are widely used in the processing of nickel-based superalloys due to their excellent wear resistance, high strength, and good hardness at high temperatures. In this paper, the high-speed milling experiments and finite element simulation of Inconel 718 are carried out by using PVD TiAlN-coated carbide tools. Simulations of tool temperature, cutting force, and chip morphology were performed to analyze the effect of cutting speed on the degree of sawtooth chip formation and the effect of sawtooth chip formation on the cutting force and tool wear. The results show that the cutting temperature mainly focuses on the rake face, and with the cutting speed increasing from 60 to 120 m/min, the maximum temperature of the rake face increases from 580 to 660 ℃. The maximum temperature region (MTR) on the rake face gradually approaches the tool nose with a decrease in the cutting speed. The generation of sawtooth chips leads to fluctuations in the cutting force component. As the cutting speed increases, the degree of chip sawing increases. The effect of the sawtooth chip on the fluctuation of the cutting force will also increase, thus increasing the degree of tool wear.

The friction mechanics model within chip-tool-workpiece dual interfaces for cutting nickel-based superalloy at the cooling and lubrication conditions of the three forms oil-on-water mist in wide temperature range

Nickel-Based superalloy has been extensively applied in the critical mechanical bearing components, such as aeroengine owing to its excellent performance at high temperature, but its machinability has always been dissatisfied. In order to improve processing efficiency, reduce cost, and decrease environmental pollution, in this paper, the friction mechanics model within chip-tool-workpiece dual interfaces was established in turning of S-type difficult-to-machine nickel-based superalloy Inconel 718 utilizing the PVD TiAlN coated carbide tool under the cooling and lubrication conditions of three forms oil-on-water mist in wide temperature range (− 30 ~ 150 ℃) (high temperature oil-on-water mist (150 ℃), normal temperature oil-on-water mist (20 ℃), and low temperature oil-on-water mist (− 30 ℃)). Meanwhile, the influence law and mechanism of the cutting speed, depth of cut, and feed on the three-way cutting forces, friction coefficient between chip-tool-workpiece dual interfaces, and normal stress and tangential stress in chip-tool interface have been studied. The results showed that the lowest and highest friction coefficient within chip-tool interface was obtained at the conditions of the high temperature oil-on-water mist (HTOoW) and the normal temperature oil-on-water mist (NTOoW), respectively. The most notable influence of the low temperature oil-on-water mist (LTOoW) on the strain hardening, strain rate hardening, and thermal softening of the materials occurred.

Machining of different superalloys under MQL using hBN nanofluids

ABSTRACT Nickel based alloys are found in industrial sectors of aerospace and gas turbines. The present study focused on the hBN nanofluid's impact on six different superalloys machinability aspects with TiAlN coated carbide tool. Further, the input-parameters optimization is through the CRITIC-WASPAS methodology. The experiments are performed by considering the workpiece, nanofluid weight concentration, speed, and feed rate based on an L18 mixed-level orthogonal design. The nickel-based samples are Nimonic 75, Inconel X-750, Nimonic C-263, Nimonic 90, Hastelloy X, and Inconel 625. The impact of nanofluids on various superalloys on the force, roughness, and residual stress are measured and analyzed. The results show that the lowest cutting force is for Inconel 625, the highest surface finish for Inconel X-750, and the lowest tensile residual stress for Nimonic 75 at the determined optimal levels of 1.00% wt. of hBN, 70m/min, and 0.14mm/rev. The highest tensile residual stress is found for Inconel 625 (779MPa) and the lowest for Nimonic 75 (673MPa). The highest roughness value is 1.294µm for Inconel X-750, while the lowest is 0.752µm and 0.780µm for both Inconel 625 and Nimonic 90. The highest cutting force of 368N is experienced for Nimonic C-263 and the least of 217N for Inconel 625.

PERFORMANCE OF COATED TUNGSTEN CARBIDE IN MILLING COMPOSITE BOARDS

The purpose of this research was to analyze the performance (wear resistance, surface roughness, chip formation, and noise level) of AlCrN, TiN, and TiAlN coated tungsten carbides in cutting composite boards. The composite boards of wood plastic composite, laminated veneer lumber, andorientedstrand board were cut by the coated tungsten carbide tools in a computer numerical control router. The results show that the differences in structure among the composite boards resulted in the difference in clearance wear, chip formation, surface roughness, and noise level phenomenon. The abrasive materials in wood plastic composite generated the highest clearance wear on the coated carbide tools tested. TiAlN coated carbide tool provided better wear resistance, smoother composite boards surfaces, and lower noise levels.

Experimental analysis on machining attributes in milling of nickel based super alloy Nimonic C-263

ABSTRACT Nimonic C263 is used to render parts of aircraft parts and it is difficult to cut owing to low thermal conductivity and high work hardening rate. Hence it results in high rapid tool wear and poor surface integrity during machining. The present work is carried out to find out the effects of the cutting speed, feed rate and depth of cut on surface roughness and flank wear in milling Nimonic C263 alloy with TiAlN coated carbide tool in dry environment. A predictive model was also developed to predict the surface roughness based on RSM (Response Surface Methodology). L9 orthogonal array was used to do experimental trails. An ANOVA analysis was performed to find the impact of the machining parameters on the surface roughness. The surface roughness was increased at lower level of cutting speed, higher level of feed rate and depth of cut. The percentage contribution of feed rate, spindle speed and depth of cut on the surface roughness are as follows 55.87%, 28.68% and 0.19% respectively. The quality of the machined surfaces and the worn-out tool were analyzed using SEM images. Abrasion wear was found at higher level of feed rate.

Tool wear mechanisms in laser-assisted milling of Nickel-based superalloys

Nickel-based superalloys are widely used in the manufacturing of aero-engine turbine disks, compressor disk, and other essential parts. The processing mechanisms result in low machinability due to the combined properties of high-temperature hardness, mechanical strength, and wear resistance. Laser-assisted machining (LAM) is a hybrid method to machine difficult-to-cut materials with the advantage of high machining efficiency, low tool wear, and high machining quality. In order to maintain the constant preheating temperature, the infrared temperature measurement point is set as a feedback value, and the laser energy is controlled by the system to ensure the milling zone preheating temperature maintaining a stable value. Laser-assisted milling (LAML) and conventional milling experiments are conducted on Inconel 718 using TiAlN coated carbide tools. Tool wear mechanisms are analyzed to investigate the influence of machining parameters on tool wear. The main results indicate that tool wear mechanisms in LAML are similar to the conventional milling, and adhesion wear is found to be the primary phenomenon leading to the milling tool wear. Tool life is longer in LAML due to the soften material and decreasing impact action on the milling tool. Besides, PVD and CVD coated carbide milling tools are used in LAML, and the experimental results show that CVD coated tool is better at the higher temperature, and it is more suitable for LAML of Inconel 718. At last, orthogonal experiments for the tool life are conducted using CVD coated tools, and the influence factors and estimation method of tool life are presented.

Machinability study of Ti-6Al-4V alloy using solid lubricant

Cutting tool suffers rapidly during machining titanium-based alloys due to low thermal conductivity. Thus most of the heat is concentrated on the tool rather than chip during machining. To overcome this problem, a suitable cutting parameter, tool geometry, and sustainable methods are necessary. This paper presents the effect of MoS2 solid lubricant (SL), cutting speed, and nose radius during turning of Ti-6Al-4V alloy using the TiAlN coated carbide tool. The experiments are performed at different cutting speeds, nose radius, and flow rates of solid lubricant to study tool wear, surface roughness, and chip morphology. The results show that the use of solid lubricant reduces the tool wear (37%), and the surface roughness (65%) compared to the dry cutting. Similarly, the effects of nose radius and cutting speed have also been studied for both conditions.

Influences of coating thickness on cutting temperature for dry hard turning Inconel 718 with PVD TiAlN coated carbide tools in initial tool wear stage

Abstract High cutting temperatures are induced in the dry cutting process of Inconel 718 for its high hardness 439 HBW and low thermal conductivity 13.4 W/(m K). Due to its thermal barrier effect and antifriction effect, the TiAlN coatings have been deposited on carbide tools with various coating thicknesses for dry turning Inconel 718. However, the influences of TiAlN coating thickness on cutting temperature of dry turning Inconel 718 were not investigated in details. In this research, PVD TiAlN tools with coating thickness 1 μm and 2 μm were fabricated and characterized. The cutting temperatures and cutting forces of dry turning Inconel 718 were measured within cutting speed ranges 30−120 m/min. Average friction coefficient at coated tool-chip interface was calculated to analyze the coating antifriction effect. Thicker coating induced large temperature increment of 19−30 °C compared with thinner coating within cutting speed ranges of 30−120 m/min in initial tool wear stage. The results showed that PVD TiAlN coated tool with coating thickness 1 μm was more suitable for dry turning Inconel 718 within cutting speed ranges 90−120 m/min by obtaining better coating antifriction effect and lower cutting temperature.

An Experimental Investigation of Cutting Tool Reliability and its Prediction Using Weibull and Gamma Models: A Comparative Assessment

This paper enlightens different methods that can be employed for assessment of cutting tool reliability. In this study the methods that are put to test are Weibull and Gamma distribution models. Test were carried out on AISI 4340 steel (35 HRC) using TiAlN coated carbide tool. Experimental results revealed that cutting tool reliability decreases with machining time. To ensure the feasibility and accuracy of the predicted results of cutting tool reliability using the Gamma model and Weibull model, multiple tool life experiments were conducted under different cutting conditions. The coeffiecient of correlation obtained for experimental values of cutting tool reliability and predicted results using Gamma model is close to one and marginally higher than the correlation coefficient for Weibull model, shows that the Gamma and Weibull models with their obtained values of characteristic parameters could be usedfor the estimation of cutting tool reliability during turning of workpiece-tool combination used in the present work.

Planetary motion cross bar friction test for application in machining process

This paper describes a new method to evaluate the friction coefficient at the tool-work interface in machining process where high stress and temperature are caused. In order to examine the feasibility of the proposed method, the present report introduces the method and the results obtained only at room temperature. Ti6Al4V, SUS304, AISI1045, FCD 700, FCD 450 and FC300 were used as work materials, while TiN coated carbide tool, TiAlN coated carbide tool and P15 were used as tool materials. The proposed method provided the friction coefficients of different coatings against different work materials, and demonstrated the variability of friction coefficient and the anisotropy of surface roughness.

Experimental investigation on surface roughness in CNC end milling process by uncoated and TiAlN coated carbide end mill under dry conditions

Abstract In this study, the effect of machining parameters on surface roughness is investigated during CNC end milling process of Al6061 – T6 Alloy by Taguchi’s method. The work material was machined with uncoated carbide tool and TiAlN coated carbide tool and comparative analysis have made between coated and uncoated tool for identifying the better surface finish. ANOVA analyses were carried out to identify the significant factors affecting surface roughness, and the optimal cutting combination was determined by seeking the best surface roughness and signal-to-noise ratio. Finally, confirmation tests verified that the Taguchi design was successful in optimizing milling parameters for surface roughness.

Material Ductile Failure-Based Finite Element Simulations of Chip Serration in Orthogonal Cutting of Titanium Alloy Ti-6Al-4V

Titanium alloy Ti-6Al-4V, an alpha-beta alloy, possesses ductile deformation behavior and offers advantageous properties, light weight but high strength, good resilience, and resistance to corrosion, becoming highly suitable for aerospace and biomedical applications. However, its machinability is still considered a limiting factor in improving productivity. This paper presents a finite element modeling methodology for orthogonal cutting titanium alloy Ti-6Al-4V by considering material constitutive modeling together with material ductile failure in combination with damage initiation and cumulative damage-based evolution to simulate not only ductile material separation from workpiece to form chips but also chip serration mechanism by applying an elastic–viscoplastic formulation. The finite element model is further verified with orthogonal cutting experiments (using both uncoated and TiAlN-coated carbide tools) by comparing simulated and acquired forces and simulated and captured chip images at high cutting speeds. The effects of cutting speed, feed, tool rake angle, and tool coating on the degree of chip serration are studied through the simulation results. The cutting temperature and strain distributions are obtained to study the chip serration mechanism under different cutting conditions. It is confirmed that the material failure, crack initiation, and damage evolution are of great significance in the chip serration in cutting titanium alloy Ti-6Al-4V.

Performance evaluation of PVD TIALN coated carbide tools vis-à-vis uncoated carbide tool in turning of titanium alloy (Ti-6Al-4V) by simultaneous minimization of cutting energy, dimensional deviation and tool wear

Titanium alloys are difficult-to-machine materials because of their poor machinability characteristics. Machining and machining performance evaluation for such materials is still a challenge. Individual machining performance indices like cutting forces, cutting energy and tool wear lead to ambiguous understanding. In this work, a Cumulative Performance Index (CPI) is defined which amalgamates non-dimensional forms of specific cutting energy, back force and average principal flank wear in turning. The CPI focuses upon simultaneous minimization of specific cutting energy, dimensional deviation and average principal flank wear. The defined index is then used to evaluate performance of five commercially available physical vapor deposited (PVD) TiAlN coated tungsten carbide/cobalt inserts vis-à-vis uncoated tungsten carbide/cobalt insert in turning of Ti-6Al-4V. Cutting forces were monitored during turning and tool wear was measured after turning experiments. The results showed that the performance of coated inserts was either comparable or poor than uncoated insert; and in no case, coated inserts performed better than uncoated insert. Although commercial recommendations are in place to use PVD coated inserts for enhanced machinability of titanium alloys, the use of coated inserts is not justified keeping in view the energy spent in coating and insignificant improvement in performance.

Investigating tool wear mechanisms in machining of Ti-6Al-4V in flood coolant, dry and MQL conditions

The objective of this study is to identify and explain tool wear mechanisms that dominate during machining of titanium alloy Ti-6Al-4V in dry, flood coolant, and minimum quantity lubrication (MQL) conditions. A series of experiments were conducted using end milling of Ti-6Al-4V by varying feed rate and depth of cut, while the cutting speed was kept constant at comparatively higher cutting speed. Both uncoated and titanium aluminum nitride (TiAlN)-coated carbide tools were used for machining Ti-6Al-4V at the same settings of parameters. It was observed that abrasion was the most dominant tool wear mechanism for all dry, flood coolant and MQL machining conditions. Edge chipping and tool nose wear were the next dominating tool wear mechanisms in conventional flood coolant machining, which may be associated with the thermal fatigue caused by the periodic cooling of tool tip from the high temperature generated during machining. On the other hand, adhesion was the second most dominant tool wear mechanism in the dry machining. Both the edge chipping and adhesion of chips to the cutting tools were reduced significantly in MQL machining. The delamination of coating film was observed when TiAlN-coated carbide tools were used for machining Ti-6Al-4V. The delamination was more significant in wet and MQL machining compared to dry machining, indicating the effectiveness of coated tools in dry machining condition compared to wet and MQL machining conditions. Among three conditions, MQL provided the least occurrences of tool wear, indicating suitability of MQL in productive machining of titanium alloys.