Uncoated Carbide Inserts Research Articles

Comparative performance evaluation between uncoated and TiAlN + AlCrN coated carbide tools in hard turning of AISI H11 steel

Cutting tools, such as ceramic, cubic boron nitride, and polycrystalline diamond, are normally preferred to machine hardened hot work steel materials which are exclusively demanded in mould and die-making industries. However, such tool materials are very costly. If carbide tools with proper coatings will be used within a particular machining range, comparative tool life can be achieved with lesser cost in hard machining. The present experimental work is based on the comparative assessment among new generation TiAlN + AlCrN coated and traditional uncoated carbide tools concerning tool life, tool flank wear, cutting temperature, cutting force, and surface integrity in dry hard turning of AISI H11 steel. The experiments with 16 trials are performed according to the L16orthogonal array by considering various machining parameters that include cutting speed, depth of cut, and feed. At last, with the measured tool life and as per Gilbert's economic approach, distinctive cost analysis has been implemented to demonstrate the cost-effectiveness of coated carbide tools in hard turning. From the experimental results, a promising machining performance is noticed for TiAlN + AlCrN coated carbide inserts in terms of all machining attributes compared to uncoated carbide inserts due to superior wear resistance, and surface hardness as well as strength of coating material. In summary, the multilayer TiAlN + AlCrN coated carbide tool offers significant cost savings (Rs. 12.82 in Indian currency), with a 9% reduction in production costs in comparison with hard turning via. uncoated insert (Rs. 14).

Studying the Effect of un Coated and Multilayer Coated Tools on Cutting Temperature in Turning Operation

The present work studies three variables (cutting velocity, feed rate, and cut depth) on hard turning cutting temperature of uncoated and multilayer-coated carbide (TiN, TiN/TiCN, TiN /Al2O3/ TiCN) inserts are used in AISI 1045 alloy steel. The tool's temperature was measured simultaneously, measuring the temperature of the tool-chip interface using infrared radiation (IR) pyrometer in this investigation. This study investigated the performance of four distinct coated and uncoated PVD and CVD tools during turning operations. Four cutting speeds (56, 88, 112, 141) m/min, four feed rates (0.065, 0.08, 0.16, 0.228) mm/rev., in the experiments, a constant cutting depth of (1) mm was used. The results also show that Coarse cutting tools have a lower tool temperature than uncoated ones. In comparison to uncoated and other coated tools, the three-layer (TiN/ Al2O3/ TiCN) coating is especially effective in a range of (32% to 39%) than uncoated inserts at various cutting velocity and constant feed rates, with varying feed rates and consistent cutting velocity and lower by approximately( 34% to 40%) than uncoated inserts.

Sustainable Machining: Tool Life Criterion Based on Work Surface Quality

Extending the use of a component without compromising its intended functionality is the neatest approach to enhance sustainability. From this perspective, limiting the working life of a cutting tool based merely on the blunting of its cutting edge to a specific value is highly questionable. The very question that serves as the motivation for this work is, “why should tool life criterion be based on the shape of the tool when all that matters for business is the quality of the part being machined?”. This work puts forward a tool life criterion based on the surface quality of the machined part. The proof of the concept is provided by a series of face-turning experiments performed on a commonly used alloy steel using the following cutting inserts in dry conditions: (1) uncoated carbide; (2) coated carbide; and (3) cubic boron nitride (CBN). It is found that different combinations of tooling and cutting parameters lead to entirely different values of surface roughness at the same level of flank wear, thus raising the possibility of extending the working life of the tools. Overall, the CBN inserts yielded the longest tool life values, especially at high levels of cutting speed. Being more economical in respect of acquisition cost than the CBN inserts and more effective than the uncoated carbide inserts regarding tool life, the coated carbide inserts came out as the most sustainable tooling option. Finally, it is concluded that a tool life criterion based on work surface roughness can yield longer tool life values and make the machining process more sustainable. For the experimental work reported herein, the surface-quality based tool life criterion yielded on average 23% longer tool life. The presented work is novel as it presents a new approach to extend the working life of cutting tools without compromising the other sustainability measures. The outcomes are expected to find applicability in all sectors of the metal cutting industry, which are striving for elongations in tool life and improvements in work surface quality.

Impacts of flank wear and cooling strategies on evolutions of built-up edges, diffusion wear and cutting forces in Ti6Al4V machining

Titanium alloys are widely used in aerospace industries due to their excellent physical and mechanical performances, however, their poor machinability always induce fast tool wear. To better understand the interaction between progressive tool wear and cooling strategies in machining of titanium alloy Ti6Al4V, an in-depth analysis towards evolutions of built-up edges (BUEs), diffusion wear and cutting forces was carried out through experimental work. Design of experiments was used towards analyzing pertinent effects involved in machining Ti6Al4V. Uncoated carbide inserts were artificially treated with different initial flank wear (VB) in order to decouple the effects involved in progressive wear condition from rake and flank faces. Dry cutting, flood cutting with emulsion and cryogenic cutting with liquid nitrogen (LN2) were used as different cooling strategies. The results show that initial VB presents significant contributions to BUEs formation, diffusion wear and cutting forces fluctuation, especially under aggressive cutting conditions. Cryogenic assistance significantly eliminates these issues compared to dry and flood conditions.

Optimization of the Dry Turning Process of Ti48Al2Cr2Nb Aluminide Based on the Cutting Tool Configuration.

Titanium aluminides are one of the most promising materials in aeronautical and automotive applications. However, their low machinability makes the processing of these alloys quite difficult under sustainability conditions, specially without lubrication. The current study focuses on the turning process of the Ti48Al2Cr2Nb gamma titanium aluminide under dry conditions. As far as we are aware, dry cutting is the most sustainable feature, although it has not been traditionally applied on titanium aluminides due to the accelerated tool wear that the material promotes. The main novelty of this work consists of providing a simple solution for reducing the tool wear based on the inclination of the cutting insert, what is evaluated in terms of tool wear and tool life, cutting forces, cutting temperature, surface integrity of the machined part, as well as its microhardness and microstructural effects. The results shown here clearly point out a better performance of the machining process. This fact could be understood if we take into consideration that an increment of the clearance angle from 6.3° to 11.6° and 15° increases the tool life by five and six times, respectively, using efficient cutting speeds, whose values have increased by 50% with respect to the original cutting conditions. This improvement is explained according to the reduction in the cutting temperature and friction forces in the flank face of the tool. In addition, the use of uncoated carbide inserts may lead to a better behaviour than the coated ones, considering the results obtained for a PVD TiAlN + AlCr2O3 coated insert herein researched.

A comparative study on physical vapor deposition - titanium carbide coated novel insert and uncoated carbide insert in CNC turning of EN24 for minimizing surface roughness and maximizing material removal rate

This study compares the performance of the PVD-TiC coated novel insert and the uncoated carbide insert in the CNC turning machine of EN24 for minimizing surface roughness and maximizing material removal rate. Materials And Methods: Physical Vapor Deposition (PVD) titanium carbide (TiC) coated insert and Uncoated Carbide tool are used to compare the machining of EN24 steel material. Total number of groups were two, and the total sample size was 54. The sample size was estimated from the clinicalc.com, with a 0.05 percent cutoff and with a G power of 80 percent. Results: The results indicate that depth of cut was the most significant factor while machining which affects the surface roughness. Mean material removal rate for PVD-TiC coated novel insert and uncoated carbide is 0.02401 and 0.02215 respectively. The significance obtained for an independent sample test is 0.045 (p < 0.05). Conclusion: Surface roughness was minimized and material removal rate was maximized when it was machined with PVD-TiC coated novel insert tool.

Sustainable manufacturing for turning of Inconel 718 using uncoated carbide inserts

In this work, sustainability in manufacturing is accomplished by introduction of a vortex tube. Vortex tube is a mechanical device that separates the hot compressed air and the cold air that flows through the tube and exits the cold air alone on to the work piece. The objective of the work is to implement sustainability in the manufacturing process for turning of Inconel 718 using coated carbide inserts. This is achieved by the implementation of vortex tube, which is used for cooling the cutting tools in turning and milling operations. Modern CNC machine tools are embedded with the vortex tube for effective heat removal process from the cutting tool. By the implementation of vortex tube, the liquid coolant is totally eliminated. The work piece considered in this work is Inconel 718. 38 mm diameter and 75 mm long cylindrical bar stock is used in this work as the test specimen for turning using uncoated carbide inserts. Design of experiments are used to conduct 27 set of experiments and for each set of experiments, the flank are measured and recorded. The flank wear is found to be decreased upto 7.2% with the implementation of the vortex tube in the turning process. The main effects plot for means for the flank wear with and without vortex tube is plotted and discussed.

An investigation on machinability of nitronic 50 in dry environment using uncoated WC-Co tool inserts

A variety of nitrogen strengthened austenitic stainless steels namely Nitronic 50 is a very useful alloy for marine industry finding its application in the form of drive shafts, pump shafts, valve fittings, pressure vessels, fasteners, sucker rods for oil rigs etc. Studies regarding machinability of this alloy is almost nil and hence it demands a proper investigation of the machining characteristics of this alloy. In the current work, turning has been performed on Nitronic 50 under dry environmental condition using uncoated tungsten carbide inserts and responses in the form of magnitude of tool-tip temperature, surface roughness, cutting force and tool wear were studied. Results showed that employment of higher cutting speed (170 m/min) resulted in enhanced cutting forces, rapid tool wear and BUE development while lower cutting speed promoted higher surface roughness. Use of cutting speed at the intermediate level of 130 m/min showed lesser tool wear, acceptable surface roughness and maintained an overall productivity.

Machinability of Ti6Al4V as influenced by cutting velocity, tool feed and cutting depth

Due to its application versatility, machining of Ti6Al4V alloy has been considered an important topic in the field of industrial manufacturing. To avoid machining-induced detrimental effects on the environment, dry machining of this difficult-to-machine alloy is a trending subject of matter. Therefore, the present study intends to explore different machinability indices such as tangential cutting force components, temperature evolved at tool-tip and wear of uncoated carbide inserts under the variations of machining parameters. A detailed study on tool wear modes and micro-morphology characteristics of evolved chips are also carried out for the present experimental analysis.

Process parameters optimization in CNC turning of aluminum 7075 alloy using TOPSIS method coupled with Taguchi philosophy

Aluminum 7075 is a very useful metal as it is used extensively in various fields of engineering like aerospace, constructions, electronics industry etc. As modern industry demand is very high accuracy of products in shorter period of time; so CNC machines are perfect solution for it. CNMG120408 uncoated carbide inserts used for machining of aluminum 7075. So in this research work, we studied the outcome of different parameters (i.e. cutting velocity (Vc), feed rate (Vf), depth of cut (Dc) and coolant pressure (Pc)) on the responses like material removal rate (MRR), surface roughness (Ra) and tool tip temperature (Tavg). Our primary objective is to find out such a parametric settings in that MRR will be maximum and Ra and Tavg is will be minimum. Here we used L16 orthogonal array and the results were optimized by TOPSIS method integrated with Taguchi philosophy.

Machinability study and optimization of tool life and surface roughness of ferrite: Bainite dual phase steel

Aim of this present research work is to obtain the machining parameters to optimize the tool life and surface roughness for ferrite-bainite dual phase steel. Machinability tests are carried out using orthogonal array of 27, the Taguchi method, in which the machining parameters are considered as control factors. The effect of speed, feed and depth of cut on tool life and surface roughness of dual phase structure steel is analysed using ANOVA. Regression analysis is used to obtain the equations for predicting the tool life and surface roughness. Experiment is conducted using uncoated carbide insert tool by varying the process parameters. Optimum tool life and surface is analysed using Response Surface Methodology. Hardness and microstructure revealed the dual phase condition in different intercritical zones. It is found that hardness improves as the intercritical temperature is increased from 750 to 770°C. Experimental results prove that dual phase structure has better machining characteristics at an intercritical temperature of 750°C.

Experimental investigation of turning process parameter under several cutting conditions for duplex steels for minimization of cutting temperature

Turning of super duplex stainless steel (SDSS) is carried out under several cutting conditions, namely, dry, wet and gas cooled cutting conditions in this work. The experiments are carried in a CNC lathe and uncoated carbide inserts tools are used for turning operations. The inserts are held in a tool holder and the turning operations are performed in controlled environment. Comparing all the three methods, the gas cooled machining gives the better performance.

Investigating the Effect of Tic Coating Layer on the Surface Roughness of Tungsten Carbide Cutting Tools Using Taguchi Design

In this study, external longitudinal turning operation was performed on (AISI 1020) steel to examine the influences of coating of the cutting tool on the machined surface roughness. The cutting tools used were coated and uncoated cemented carbide inserts. The tests are performed at four spindle speeds (80, 315, 500, and 800) rpm, at each of which two feed rates (0.2 and 0.5mm/rev) and two depth of cut (0.5 and 0.7mm) were used. Taguchi design of experiments (DOE) with a designed mathematical predictive model was used to investigate the effect of the coating layer and determine the machining conditions for minimum surface roughness. Accordingly, a suitable mixed orthogonal array L16 (3*4) was selected. The results showed that the surface roughness produced by using TiC coated inserts for identical machining conditions was lower than that produced due to uncoated tool by 41% to 53%. Regression analysis showed that the non-linear quadratic polynomial equation appears to be more suitable for representing the relation of spindle speed, feed rate, and depth of cut with the surface roughness. Taguchi method and the designed mathematical model had been used to predict the optimal cutting conditions. A confirmation test for the obtained results verified that the designed Taguchi experiments and the designed model successfully investigated the effect of the coating on the surface roughness. Data fit ver.9 and Mtb14 software had been employed to achieve the object of the presented work.

RETRACTED: Development of multi sensor fusion based DAQ for in-process TCMS: Experimental and empirical analysis

In order to manufacture low-cost, high-quality goods, in-process tool condition monitoring is an essential responsibility in the manufacturing industry. In this study, a multisensor fusion technique was used to build and execute an effective and reliable TCM system in turning operations with coated and uncoated tungsten carbide inserts. In dry turning, an attempt has been made to optimize the turning process parameter and monitor the tool's condition. Acoustic optic emission based sensor i.e., Laser Doppler Vibrometer and FLIR E60 infrared thermal camera are strategically placed near the machining zone. Thermal images and vibration signals are recorded using an appropriate charge amplifier. To extract characteristics from numerous sensor data, a National Instruments data acquisition (NI-DAQ) system is constructed utilizing LabVIEW software. Thermal images are used to gather temperatures from tool-work piece locations. Vibration signals are translated into vibration parameters. These characteristics serve as the foundation for establishing in-process TCMS. Tool wear, vibrational displacements (Disp), and cutting temperature are investigated as a result of varied tool insert materials and process conditions (CT). Utilizing ISO 10816-3, ISO 3685, and ISO-18434-2008 standards, the cutting tool condition was assessed using extracted features from multi sensor fusion techniques. For Ti-6Al-4 V, the displacement of uncoated and coated tools increased by 65.28% and 44.71%, respectively. For AISI 316L flank wear, the uncoated insert effected 41% and the coated insert impacted 24.14%, respectively. While machining Al7075, the relationship of depth of cut and feed rate on flank wear maintains an identical trend. It is discovered that both temperature and displacement have a significant role in the evolution of flank wear, which is examined in depth. This paper recognizes the use of multi-sensor data in tool condition monitoring when rotating with various cutting tool inserts.

Surface integrity optimization in high speed milling of AZ91 magnesium alloy using TOPSIS considering vibration signals

AZ91 magnesium alloy have gained vast attention in the recent years for its low density and good mechanical properties which is crucial in improving the automobile-aerospace vehicle efficiency. High speed dry face milling operation is performed on AZ91 magnesium alloy using uncoated carbide inserts and the material behavior is investigated. Spindle speed, feed rate and depth of cut are the input parameters considered to investigate the material behavior alterations in terms of surface roughness and hardness. Taguchi design of experiments (DOE) is implemented to reduce the overall machining costs and time and Techniques for Order Preferences by similarity to Ideal Solution (TOPSIS) statistical analysis tool is utilized to identify the optimal machining conditions. Further, machining vibration signal analysis is performed using time domain analysis to correlate the vibration signals and surface roughness characteristic

High-pressure flank cooling and chip morphology in turning Alloy 718

The use of cutting fluids is commonly considered a necessity while machining Heat Resistant Super Alloys (HRSA). Specifically, cutting fluids applied under high-pressure, which for many decades have been the solution for the most demanding applications. The results might be diverse and vary between applications, but typically leads to improved tool life, enhanced chip breakability, lower temperature in the cutting zone and better surface quality of the finished product. The available high-pressure cutting fluid delivery systems are usually designed with the intention to improve the cutting fluid penetration at the vicinity of the cutting edge on the rake face side of the insert. However, there has been limited interest in investigating high-pressure cutting fluid applied to its flank face. Both specifically and in combination with cutting fluid directed to the rake face. In this study, the focus has been to investigate the chip formation process during the turning of Alloy 718 (Inconel 718). Particularly, for a defined turning operation where high-pressure cutting fluid is applied to the flank side as well as the rake side of an uncoated carbide insert. Several combinations of pressure levels and jet directions were investigated. The corresponding effects on the tool-chip contact zone and chip characteristics were studied for two cutting speeds. The results of the investigation showed a substantial improvement in lowering the tool-chip contact area at a rake pressure of 16 MPa. At which pressure, additional cutting fluid applied to the flank at a moderate pressure of 8 MPa had no dominant effect on chip formation (chip break). However, flank cooling of the cutting zone supports chip segmentation and thus indirectly chip breakability. For cutting fluid applied to the rake side at a more moderate pressure of 8 MPa, more prominent effects on the insert became apparent when additional cutting fluid was applied to the flank side. This was particularly noticeable when cutting fluid was directed towards the flank side of the insert at the same pressure level as the cutting fluid applied towards its rake face. The additional thermal transfer was seen to have a significant effect on the material deformation phenomena in the primary shear zone (lowering shear angle) as well as the sliding and sticking conditions of the tool-chip interface. Based on the evidence from this study, it can be concluded that cutting fluid applied towards the flank side of the insert has a significant impact on the cutting process. In particular, if applied in combination with a rake pressure at a similar level, in this case, 8 MPa.

Hybrid Taguchi-PCA-utility approach for simultaneous optimisation of multiple responses in turning alloy steel

ABSTRACT This study focussed on the multi-response optimisation of turning process using an easier and accurate hybrid approach namely Taguchi-PCA-Utility approach. Turning of alloy steel under dry and LN2-assisted cryogenic cooling with two different geometry-shaped uncoated carbide inserts was carried out based on suitable design of experiments (Taguchi L16 orthogonal array). Five vital responses in turning such as temperature, roughness, feed force, cutting force and MRR were measured by varying the input factors (speed, feed, cutting condition and cutting inserts type). Principal component analysis (PCA) for relative weight calculation of responses and utility concept for deriving out the unified process index were followed. The optimum parameter settings for maximum utility value were found at 134 m/min speed with 0.12 mm/rev feed rate under cryogenic cooling using SNMG 120408-type cutting insert. Finally, in order to verifying the significance of proposed approach validation tests were conducted.

Experimental Investigation of Nano Fluid in Machining Process to Enhance the Performance

The surface roughness is paying a very dominant role in manufacturing industries. It is one of the parameters that cannot be avoided in machining process. Investigation was done on turning titanium alloy grade 2 with uncoated carbide insert in a CNC lathe. During machining on titanium, the high cutting temperature found, because of that friction in tool causes, for that purpose we are carry more cutting fluid, cutting tool &amp; actual machining parameter. The present work shows the concentration of multi-walled carbon nanotube (MWCNT) &amp; Graphene nano-particles are in used. The Nano fluid is prepared by using various ratios of nano-particles (MWCNT &amp; Graphene), rice bran oil and blended oil as a base fluid. sodium dodecyl benzene sulfonate (SDBS) Surfactant added in cutting-fluid to provide better lubricant properties. The statistical planning of the experiment is done by using Taguchi method. The process parameters considered in the study are cutting speed, feed rate, depth of cut and surface roughness is considered as a response parameter.

Performance Comparison of PCD Insert and Uncoated Insert in Novel CNC Green Machining of SS316L Stainless Steel for Maximizing Material Removal Rate

Aim: This research is about comparing the performance of poly-crystalline diamond (PCD) insert and uncoated cemented carbide insert for improving the material removal rate (MRR) in CNC turning. Materials and Methods: The material investigated in this research was SS316L. PCD insert was set as the experimental group and uncoated insert was set as the control group. The cutting parameters employed in this process were cutting speed, feed rate and depth of cut. Totally 27 samples per group were machined by using the selected parameters. Results: The mean MRR value obtained for the PCD tool is 0.22593 g/s, whereas it is 0.07600 g/s for the uncoated tool. The significance value obtained among the experimental group and control group is 0.000 (p&lt;0.05). Conclusion: Within the limits of this study, the outcome of the research shows that MRR is more when the specimen is machined by PCD insert than machined by uncoated insert.

Multiple Response Optimization of machining parameters on turning of AA 6063 T6 aluminum alloy which established on Taguchi L9 orthogonal array coupled with Grey relational analysis

With numerous responses established on Taguchi L9, orthogonal array coupled with current work proposes a novel methodology for optimizing machining parameters on turning of AA 6063 T6 aluminum alloy. Experimental assessments are accomplished on AA 6063 T6 aluminum alloy. Turning trails are carried out under dry cutting conditions using an uncoated carbide insert. Cutting parameters such as cutting speed, feed rate, and depth of cut are optimized in this effort while numerous responses such as surface roughness(Ra) and material removal rate are taken into consideration (MRR). From the grey analysis, a grey relational grade(GRG) is calculated. The optimal amounts of parameters have been identified based on the values of grey relational grade, and then ANOVA is used to determine the significant influence of parameters. To authenticate the test result, a confirmation test is executed. The result of the experiments shows that by using this method. the turning process responses can be significantly improved.