Carbide Inserts Research Articles

Optimisation and modelling of burr formation during face milling of rolled steel (AISI 1040) using Taguchi approach

ABSTRACT Burr formation on the edge of the machined part during face milling is a common phenomenon. Highly precise and accurate parts are required to be burr free. Generally, deburring (secondary operation) is performed to remove the burr, which leads to the cost of the part. The aim of this study is to obtain minimum exit burr by optimising the input parameters at primary stage of the face milling operation. Effect of machining parameters (cutting velocity, feed per tooth, axial depth of cut), and machining strategies (rolling direction, cutter offset, soaking time during heat treatment) are taken into consideration. Taguchi’s L27 matrix is selected for the design of experiments. Face milling of rolled steel (AISI 1040) is performed on vertical milling centre using titanium nitride coated carbide inserts. Exit burr is evaluated as a signal to noise ratio. The significance level and percentage contribution of parameters are calculated using analysis of variance. Cutter offset has shown maximum contribution followed by cutting velocity. Burr reduction of 58.4% is observed during a confirmation test. Finally, multi-variable linear regression is employed to generate second-order empirical model. Adequacy of model is checked by residual analysis.

EXPERIMENTAL STUDY ON THE SURFACE ROUGHNESS AND OPTIMIZATION OF CUTTING PARAMETERS IN THE HARD TURNING USING BIOCOMPATIBLE TiAlN-COATED AND UNCOATED CARBIDE INSERTS

Machining of difficult-to-cut materials has always been a focus of research. In terms of surface roughness, it is one of the most important machinability indicators used to evaluate the performance of machining processes. This research aims to investigate the effect of biocompatible TiAlN-coated and uncoated carbide inserts, as well as the effect of cutting parameters such as feed, rotational speed, and depth of cut on surface roughness in the hard turning of M2 tool steel at 64 HRC. The central composite design is used to create the experimental layout. Surface roughness values are measured using separate experiments for coated and uncoated inserts. A quadratic model is selected, and an analysis of variance (ANOVA) is performed to test the adequacy of the developed model. From the ANOVA, it is found that feed and rotational speed are the most significant parameter while hard turning with TiAlN-coated and uncoated inserts, respectively. Cutting parameters are ranked according to their importance using the Pareto chart. The composite desirability function is employed to determine the optimal setting of cutting parameters to minimize the surface roughness and a confirmation experiment is conducted to validate the optimization results. Confirmation results are very close to the predicted value and the error between experimental and predicted results are 7.93% and 9.36% with TiAlN-coated and uncoated carbide inserts, respectively. TiAlN-coated carbide insert gives better surface roughness compared to an uncoated carbide insert.

The oxidation behaviors of TiB1.73, Al0.59Ti0.41N, and TiB1.73/Al0.59Ti0.41N coatings deposited by high-power impulse magnetron sputtering method

Transition metal nitrides and diborides have high melting points, excellent chemical stability, and good thermal conductivity. However, these materials typically suffer from oxidation when served in high-temperature environment. In the present work, the single layer TiB1.73, Al0.59Ti0.41N, and bilayer TiB1.73/Al0.59Ti0.41N coatings with ~4–6 μm thickness have been deposited on cemented carbide inserts by high-power impulse magnetron sputtering (HiPIMS) method. The oxidation behavior and phase transition of these coatings at elevated temperatures (400–900 °C) are investigated by means of a hybrid approach of experiments and phase diagram calculations. TiB1.73 and Al0.59Ti0.41N coatings grow in columnar form. Anatase is the first generated product during TiB1.73 coating oxidation at 400°C for 1 h, then the amount of rutile phase gradually increases with the rise of oxidation temperature. Oxide layers for TiB1.73 coating are porous and show oxidation delamination phenomenon, which are related to the evaporation of B2O3 (g) and the transformation of anatase to rutile. Anatase is also firstly formed during the oxidation process at 700 °C for Al0.59Ti0.41N coating. Subsequently, a protective Al-rich oxide layer is generated and this layer is broken after oxidation at 900 °C. The initial oxidation behavior of bilayer TiB1.73/Al0.59Ti0.41N coating is similar to that of TiB1.73 coating, but aluminum oxides are observed after oxidation at 650 °C. The B element on TiB1.73/Al0.59Ti0.41N coating surface is gradually exhausted with the increase of oxidation temperature.

Study on wear morphology of uncoated and MT-CVD TiCN-Al2O3 coated carbide inserts during dry machining of Inconel 825 superalloy

The adoption of the High Speed Machining (HSM) approach by industries to enhance productivity is crucial in order to fulfill the growing demand of the global market. Understanding superalloys' machining behavior is also necessary since they play a significant role in a variety of industries, including the aerospace industry, marine engine parts, biomedical applications, chemical and petrochemical industries, and nuclear fuel processing plants. Hence, dry machining performance of ‘difficult-to-cut’ aerospace superalloy Inconel 825 is studied herein. With uncoated and MT-CVD TiCN-Al2O3 coated carbide inserts, machining experiments are performed at various cutting speeds. Detailed tool wear mechanisms are discussed for each of the cutting inserts with regard to different cutting speeds and hence the performance gain with coated carbide tools is understood as compared to its uncoated counterpart for dry machining of Inconel 825 superalloy.

Assessment of the surface integrity of AISI H13 tool steel after milling with carbide and cermet inserts

Assessment of the surface integrity of AISI H13 tool steel after milling with carbide and cermet inserts

Investigation on Surface Integrity in Hard Turning of AISI 4140 Steel with SPPP-AlTiSiN Coated Carbide Insert under Nano-MQL

The machined surface integrity in the turning of hardened steels is adversely influenced by heat generation and friction which requires pacification of the temperature by the effective cooling-lubrication approach and cutting tool performance. The present research analyzes the surface integrity of hardened AISI 4140 steel during turning with recently developed scalable pulsed power plasma SPPP-AlTiSiN coated carbide tool under nanofluid-assisted minimum quantity lubrication (MQL). Zinc oxide nanoparticles and environmentally friendly radiator coolant are mixed to prepare the nano cutting fluid. This analysis addresses the various aspects of surface integrity concerning surface morphology, machined surface hardness, residual stress and white layer development, and machined surface finish under varying cutting parameters (depth of cut, speed, feed, nose radius). Response surface methodology (RSM) is suggested to predict and to optimize the surface roughness in hard turning. Thereafter, the predictive modelling and optimization results are implemented for economic analysis. According to the findings of the experiments, with a contribution of 58.18%, the feed rate possesses a high impact on the surface finish, followed by the nose radius (12.32%) and speed (0.85%). Consequently, the machined surface quality improved with the increase of the nose radius because of the minimum tool wear and due to the increase of the effective length of the cutting edge. At optimum cutting conditions, the tool life of SPPP-AlTiSiN coated carbide insert is noted as 46 minutes under nanofluid-MQL and consequently, it estimated the overall machining cost per component as Rs.23.12 in Indian currency.

Optimization of process parameter in AI7075 turning using grey relational, desirability function and metaheuristics

ABSTRACT Even though metal may be effectively shaped by a variety of other manufacturing techniques, machining continues to play a significant role in industries. Turning is a conventional chip-forming operation that removes undesirable or surplus material from a cylindrical workpiece. The major objective of process optimization in turning operation research is focusing on the development of statistical modeling and optimization techniques for boosting production rate, lowering costs, and reducing product rejection. The current work aims to improve the CNC turning process of Al 7075 using coated carbide inserts. This investigation uses grey relational analysis, desirability function analysis, Multi-objective Genetic Algorithm (MOGA) and Multi-objective Genetic Particle Swarm Optimization (MOPSO) to optimize factors to minimize responses like surface roughness and cutting force. Comparative evaluation of results of optimum input parameter sets results in close agreement, both in traditional optimization and metaheuristic-based optimization. In particular, MOGA is found to be more efficient to solve this stated multi-criterion decision-making problem as compared to other methods.

Investigation on the effect of machining parameters on 42CrMo4 DPS steels

Machining 42CrMo4 martensite—ferrite dual phase steel is challenging due to its high hardness and it is essential to determine the favorable requirements for the optimum machining condition. The ability to alter the martensite quantity in dual phase structure of steel leading to variation in bulk hardness is the motivation for machinability investigation. In heavy duty machining, the determination of tool life and surface roughness at various conditions of machining plays an important role in the manufacturing industry. In the present work, machinability tests are carried out on 42CrMo4 martensite—ferrite dual phase steel to assess the tool life and surface roughness. Speed, feed, and depth of cut are varied in different levels. The tests are carried out as per the full factorial method. A microstructure study is performed to correlate the various mechanical properties with phase morphology. The main objective of this study is to obtain the optimized machining process parameters for the turning operation of 42CrMo4 martensite—ferrite dual phase steel. All cutting tests are carried out under dry conditions using a carbide insert. Microstructure and mechanical property analysis shows an increase in the martensite quantity with the increase in the dual phase processing temperature. From the ANOVA results, it is found that the depth of cut is the major contributing factor to the variation of tool life and surface roughness within the range of values considered for the study. Microstructure analysis revealed the distribution of ferrite and martensite phases evenly. The optimum combination of machining parameters is calculated for obtaining a superior combination of tool life and surface roughness. The 42CrMo4 DPS steel may be used for structural applications with wide variation in the property range.

Investigation on the Performance of Coated Carbide Tool during Dry Turning of AISI 4340 Alloy Steel.

The machinability of materials is highly affected by their hardness, and it affects power consumption, cutting tool life as well as surface quality while machining the component. This work deals with machining of annealed AISI 4340 alloy steel using a coated carbide tool under a dry environment. The microhardness of annealed and non-annealed workpieces was compared and a significant reduction was found in the microhardness of annealed samples. Microstructure examination of the annealed sample revealed the formation of coarse pearlite which indicated a reduction of hardness and improved ductility. A commercially CVD multilayer (TiN/TiCN/Al2O3/ZrCN) coated cemented carbide cutting tool was employed for turning quenched and tempered structural AISI 4340 alloy steel by varying machining speed, rate of feed, and depth of cut to evaluate the surface quality, machining forces, flank wear, and chip morphology. According to the findings of experiments, the feed rate possesses a high impact on surface finish, followed by cutting speed. The prominent shape of the serrated saw tooth chip was noticed at a higher cutting speed. Machined surface finish and cutting forces during turning is a function of the wear profile of the coated carbide insert. This study proves that annealing is a low-cost and economical process to enhance the machinability of alloy steel.

Схема формообразования задней поверхности пятигранных твердосплавных пластин на станках с ЧПУ

The methods of grinding the rear surfaces of multifaceted carbide inserts, as well as various schemes for shaping the back surfaces, are considered. The process of shaping the rear surface of a five-sided carbide insert is modeled. An algorithm for the implementation of the kinematic scheme for shaping the rear surface of pentahedral carbide plates using CAD tools has been developed. The processing of a multifaceted carbide inserts on a CNC grinding and grinding machine was carried out using the obtained mathematical dependence.

Performance evaluation of different carbide inserts in turning of newly developed Al‐12Si‐0.1Sr alloy

AbstractAn Al‐12Si‐0.1Sr alloy ingot was manufactured using a permanent mold casting technique. The microstructure and mechanical properties of this alloy were researched. Effects of different cutting conditions (cutting speed‐V: 200 m/min, 300 m/min, and 400 m/min and feed rate‐f: 0.05 mm/rev, 0.1 mm/rev, and 0.15 mm/rev) on the cutting force (F) and surface roughness (Ra) during machining using uncoated and physical vapor deposition‐ titanium aluminum nitride coated carbide inserts were also revealed. Microstructure of the alloys consists of α phase, intermetallic δ and Al4Sr phases, thin spherical eutectic, and irregular coarse‐shaped primary silicon particles. Cutting force and surface roughness decreased with the increased cutting speed during turning with uncoated, and titanium aluminum nitride coated inserts while they increased feed rate. A built‐up edge and built‐up layer were formed in both cutting inserts. The built‐up edge and built‐up layer decreased with increasing cutting speed and increased feed rate. The cutting force, surface roughness, built‐up edge, and built‐up layer were lower in uncoated inserts compared to the titanium aluminum nitride coated inserts.

On the mechanism of rock fracture with tools made of hard alloys and polycrystalline superhard materials

When studying the process of rock fracture with tools equipped with polycrystalline superhard materials (PSHM) and hard alloys, the main regularities of the fracture mechanism, despite the significant differences in physical and mechanical properties of the used tool materials, are assumed to be identical. This approach not only reduces the efficiency of using the created rock-destroying tools, but also limits the scope of application of polycrystalline superhard materials. Experimental studies using various methods of obtaining information shown significant differences in the mechanism of rock fracture by hard alloys and polycrystalline superhard materials. The study of the zone of the pre-destroyed surface showed that when cutting rocks with PSTM, the process of destruction is carried out not only by the entire polycrystalline plate, but also by ridged diamond formed on the cutting edge and rear surface of the tool. At the same time ridged diamonds, when embedded in the rock, create high contact stresses and an additional network of microcracks interacting with microcracks formed due to the embedding of the entire cutting edge of the plate. The impact of two independent indenters simultaneously increases the zone of the pre-destruction layer in the rock mass, which leads to a more significant decrease in its strength and, as a consequence, to the intensification of the process of rock destruction by the PSTM tool. In case of wrong choice of PSTM application area and operation modes, errors in tool design and insufficient cooling, ridges are not formed on the cutting edge and back surface of the polycrystal. As a result, the polycrystalline insert works as a carbide insert and the efficiency of the PSHM tool is sharply reduced. The use of knowledge obtained as a result of the conducted research makes it possible to create tools equipped with diamond-hard-alloyed inserts, the wear resistance of which is dozens of times higher than that of similar tools made of hard alloy. For example, effective tools equipped with diamond-hard-alloyed inserts have been created and widely introduced into practice for rotary drilling of boreholes, degassing wells, anchoring of mine workings, saw stone cutting, drilling of abrasive permafrost soils and others. Keywords: polycrystalline diamonds cutters (PDC), hard alloys, pre-destruction zone, rock breaking tools, rock destruction.

STUDY OF DURABILITY IN THE CONNECTION “CONE-TUNGSTEN CARBIDE INSERT” FOR TENSION DEPENDENCE

During and after the technological operation of pressing these factors significantly determine the residual stress states of tungsten carbide inserts, as well as in the areas near the holes of the cones’ crowns of the cone. The stressed state of the inserts and the magnitude of the stress concentration determine their fatigue strength of them and the durability of the inserted carbide rock-blasting equipment of the cones in the area where the inserts the cone. Dimensional analysis was done for the inserts and holes in the cones of bit and it was established that size errors of component links of dimensional chains are distributed according to laws that are similar to the normal law of distribution of random variables. The test was carried out according to the criteria of Pearson and Kolmogorov. The influence of various random and systematic factors results to the dispersion of dimensions on the dimensional processing of conjugated surfaces. The amount of tension is a function of the dimensions for mating surfaces during assembly operations. Dispersion of dimensions for the component links of the dimensional chain of a press connection causes the formation of a practical field of dispersion of the closing link. Accuracy control for the closing link in the dimensional chain is impossible if there are no direct measurements of the constituent links. A mathematical model of the process of assembling "cone-tungsten carbide insert" joints was created. For this, the methods of mathematical statistics were applied in the study. It was established that the tension values have a greater influence on the force of pressing inserts into the holes of drill steels 14 NiCrMo1, when its hardness value is HRC 59-60 compared to HRC 48-50. This dependence has a linear character within the limits of the studied tension values. The established relationships make it possible to reasonably and most accurately form selective groups of inserts and mark holes for them. This method significantly reduces losses in the production of drilling tools.

Tool Life of Uncoated and Coated Inserts during Turning of Ti6Al4V-ELI under Dry and Minimum Quantity Lubrication Environments

This paper mainly deals with the tool wear characteristics of uncoated cemented carbide insert and PVD AlTiN, PVD TiAlN coated carbide inserts during turning of Ti6Al4V-ELI (Extra Low Interstitial). To satisfy the sustainability conditions, the experiments have been conducted under dry and minimum quantity lubrication (MQL) environment. To enhance the effectiveness of MQL, palm oil has been used as the cutting fluid. The same machining parameters are employed for all the cutting tool inserts in dry and MQL environments to understand the machining characteristics better. It was found that cutting speed greatly influences average flank wear. Tool life of PVD TiAlN coated tool is more in both MQL, and dry environments as compared to uncoated cemented carbide insert and PVD AlTiN coated insert. Using palm oil under the MQL environment has produced better results while turning by PVD TiAlN insert. The characteristics like good cooling and lubrication provided significantly less average flank wear during machining of Ti6Al4V-ELI under the MQLenvironment.

Influence of coatings based on Zr and Ti on the wear resistance of cemented carbide tools when turning transport machines’ parts from structural steels

The influence of coatings based on titanium carbide and zirconium carbide, obtained by PVD method, on cutting tool wear resistance under conditions of the longitudinal turning of transport machines’ parts of steel 45 and stainless steel 12H18N10T by inserts of hard alloy grade T15K6 was investigated. It has been experimentally established that the presence and composition of the coating on the working surfaces of the tool in most cases contributes to a significant reduction in the intensity of wear of cemented carbide inserts. When turning stainless steel 12H18N10T, the best result was demonstrated by the coating ZrN + (Ti–Zr) N + TiN, which provided not only the minimum intensity of wear, but also the expansion of the range of optimal cutting speeds. When machining structural steel 45, the maximum reduction in the wear intensity of the cutting inserts was observed with the use of a single-layer TiN coating and a (Ti,Zr)N coating.

Investigations of tool wear of coated carbide tool while machining X-750 nickel alloy

Modern advanced structures and machinery rely heavily on advanced materials. Ni-based superalloys have applications in nuclear power plants, gas engines, airplane engines, turbines, etc. All these environments have high temperatures, thus; the material is selected such that it demonstrates sufficient strength at high temperatures. Ni-based superalloys present this characteristic due to their “high strength temperature resistant” (HSTR) nature. In the present work, an attempt has been made to machine X-750 nickel alloy on conventional machining considering rotational speed (TRS), feed (F) and depth of cut (DoC) as input machining variables. The coated carbide insert has been used at different machining cutting of input machining variables. The tool wear is assumed as an output parameter and the effect of input of parameters on the tool wear has been investigated. It has been observed that with the increase in rotational speed, feed and depth of cut the value of flank wear increases. The main mechanisms of tool wear exist in the present study are abrasion, adhesion and chipping, which are observed after the analysis of tool inserts by optical as well as scanning electron microscopy. The optimized setting for minimum TW (0.2716 mm) is TRS: 1362RPM; DoC: 01 mm and F: 0.07 mm/rev.

Experimental analysis for turning of Ti6Al4V alloy by tungsten carbide coated tool inserts

Due to their exceptional characteristics, titanium alloys are suitable for technical and medicinal applications. These alloys are difficult to machine due to their low heat conductivity and low elastic modulus, which produce high cutting forces and tool wear. This study used tungsten carbide inserts to dry-turn titanium alloy (Ti6Al4V). Cutting speed, feed rate, and depth of cut were chosen as the input process parameters for machining, while cutting force, and surface roughness were the output responses. The experimental design is based on three factors at a three-level partial factorial L9 orthogonal array, and it was created using Minitab® 17 statistical software. Analysis of variance and the Taguchi S/N ratio was utilized to analyze the data. The minimum cutting force (115 N) and average surface roughness of 1.6 μm were found at a cutting speed (450 rpm), feed rate (0.1 mm/rev), and depth of cut (0.5 mm). While machining, it was found that feed rate contributes less to cutting force than the depth of cut and cutting speed. Among the combinations tested, a cutting speed of 450 rpm, feed rate of 0.1 mm/rev, and depth of cut 0.5 mm provided the most remarkable overall machining performance.

Влияние мультиграфена на стойкость пластин из твердых сплавов

In the work, experiments were carried out on the production and testing of hard alloys from powders of the VK10KHOM and VRK15 grades coated with multigraphene obtained by the electrochemical method. Samples with multigraphene were sintered under standard conditions for grades VK10KHOM and VRK15. In the weight ratio, the amount of multigraphene was 0.1 wt. % for the VK10KHOM grade alloy and 0.1 wt. % and 0.5 wt. % for the VRK15 grade. Friction tests of VK10KhOM samples showed that the width of the wear areas of samples with multigraphene is 8 % less than in the original ones. At 0.1 wt. % graphene, the density of the VK10KHOM grade is 14.5 and VRK15 is 14.0, and the porosity is 0.02 % and 2 %, respectively. Comparative tests were carried out on cutting titanium grade VT-3. As a result of cutting, it was found that the coating of powders with multigraphene increases the resistance of carbide inserts of both grades. It is shown that for VRK15 the plate durability increased by 4 times, and for the VK10KHOM grade it was not possible to establish the plate failure time. The increase in wear resistance is presumably caused by a decrease in the coefficient of friction due to multigraphene, which, dissolving in the hard alloy, precipitates in the form of nanographite clusters.

Influence of milling parameters on Al-Li alloy surface characteristics

Lightweight alloys attract the aerospace industries due to their high specific strength. Al-Li alloy has been investigated in the present study to identify their functional performance in terms of surface characteristics namely surface roughness and hardness. Dry face milling was performed using uncoated carbide inserts for the experimental conditions obtained from Taguchi L27 design of experiments. The effect of milling parameters, such as feed rate, cutting speed and depth of cut on surface roughness and hardness have been investigated and presented. Further, the optimal milling conditions are identified using statistical techniques – Grey Relational Analysis (GRA) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The study showed that feed rate is the most influential parameter on both surface characteristics. Both GRA and TOPSIS showed similarity in identifying the same condition as optimal for milling Al-Li alloy under dry condition.

EFFECTS OF VARIOUS VEGETABLE OIL AND WATER MIXTURES USED AS CUTTING FLUIDS ON TOOL WEAR AND SURFACE ROUGHNESS

In the study, various vegetable oil and water mixtures were used as cutting fluid to be tested in machining. These fluids have been used as an alternative to cutting fluids made from synthetic and semi-synthetic oils, which have harmful effects on nature and humans, and their performance has been investigated. As vegetable oil, Soy, Sunflower and Canola oils were mixed with water each and separate cutting fluids were obtained. Vegetable oil and water were mixed at 7 % and 93 %, respectively, and turned into a homogeneous liquid. Dry cutting and commercial cutting fluid using for cutting was also performed in comparison turning. In the study, AISI 4140 steel was processed on a CNC turning machine using an uncoated carbide insert. In all experiments, the cutting speed was kept constant as 200 m/min, the feed rate as 0,2 mm/rev, and the depth of cut at 1 mm. Cutting fluids were used in two different ways in experiments as liquid and 4 bar pressure spraying. As a result of the experiments, tool wear and surface roughness values were studied. The best results in all processing terms have been found in experiments with pressurized spraying of a mixture of canola oil and water. The surface roughness value was measured as 1,35 μm and the tool wear value was measured as 0,13 mm. The worst values were obtained in experiments carried out under dry cutting condition. Surface roughness value was measured as 2,31 μm and tool wear value was measured as 0,24 mm.