Ceramic Tool Inserts Research Articles

Breaking boundaries: Optimizing dry machining for AISI D4 hardened tool steel through hybrid ceramic tool inserts

Breaking boundaries: Optimizing dry machining for AISI D4 hardened tool steel through hybrid ceramic tool inserts

Comparative analysis over microstructural, mechanical properties and cutting performance of TiN, TiVN coatings deposited by magnetron sputtering on SiAlON ceramic tool insert

In this work, TiN and TiVN hard coatings were deposited by magnetron sputtering process on SiAlON cutting tools. FESEM and XRD were used to analyze the coating's microstructure and phase composition. The hardness of the coatings was measured through nanoindentation test and the adhesion of the coatings was determined using the scratch test. Turning tests were carried out on uncoated, TiN and TiVN coated cutting tools in D3 hardened steel turning under dry environment. Tool life, wear progression, and cutting force were investigated under different cutting parameters. Meanwhile, the wear patterns and mechanisms were studied. Surface roughness after machining and cutting temperature during machining were also recorded and analyzed during the experimentation work. Chips after every set of experiments were collected and their morphology study was done using FESEM. For cutting tools coated in TiN and TiVN, abrasion with grooves on the worn faces was the main wear mechanism. The results indicate a significant optimization in performance, with cutting forces minimized by up to 30 %, cutting temperatures reduced by 20 %, and machined surface roughness improved by 45 % when compared to the TiN coated cutting tool. The experimental findings showed that the TiVN-coated SiAlON cutting tool outperformed the uncoated cutting tool and the TiN coated SiAlON cutting tool in terms of cutting performance. This research additionally offers a comparative experimental behavior of coated cutting tools, along with an investigation into cutting performance, which is essential for advancing research and enhancing our understanding of machining hardened steels.

Machining performance of ceramic tool inserts during dry turning of hardened steel

For effective dry turning of hardened steels, ceramic tool materials have long been utilized as an alternative to conventional tool materials. Therefore, the purpose of the current work is to investigate whether ceramic materials like alumina (Al2O3) are suitable for use as tool materials during the dry (without coolant) turning of hardened steels. In addition, while cutting EN 24 hardened steels, the performance of an alumina ceramic tool insert was compared to a commercial tool insert in the current work. On EN 24 steel samples, turning operations were performed utilizing both alumina ceramic tool inserts and commercial carbide tool inserts at different machining parameters such as speed, feed, and depth of cut. The turning performance of both alumina and commercial tool inserts was evaluated at various machining conditions based on abrasive wear (weight loss) of the tool inserts and the surface roughness of EN 24 machined samples. At all machining parameters, it was found that the abrasive wear of ceramic tool inserts was lower than the abrasive wear of commercial tool inserts. It is observed that, the surface roughness of EN 24 machined samples when machined with ceramic tool inserts was a little higher when compared with the surface roughness values of EN 24 machined samples which are machined with the commercial tool insert. The results of the experiment showed that ceramic cutting tools had comparable cutting performance to commercial cutting tools.

Cutting temperature of graphene reinforced ceramic cutting tool inserts during dry turning of hardened steels

The amount of heat generated during machining operations under high speed and depth of cut inherently produces high temperatures at the cutting zone. Therefore, the temperature generated at the cutting junction of the tool and workpiece is a crucial parameter in determining the quality of the finished product. The effect of the generated cutting temperature, especially at elevated temperatures, primarily affects both the workpiece and the cutting tool. Knowledge of the cutting temperature generated at the tool tip can improve tool life and machining performance. In this work, turning operations were performed on a hardened steel workpiece of grade EN24 and EN36 using alumina-graphene composite ceramic tool inserts under different machining conditions on a precision lathe without coolant (dry machining). The maximum temperatures generated (offset temperature, i.e., 4 mm away from the tool insert tip) at the tool insert were measured during the turning of hardened steel workpieces with the aid of a calibrated thermocouple. A study was also conducted on the effect of different weight percentages of graphene in alumina ceramic tool inserts on the generated offset temperatures. During the machining of both the EN24 and EN36 samples, it was clearly observed that offset temperatures generated at composite tool inserts reinforced with 0.35 wt% and 0.45 wt% of graphene were lower at all machining conditions compared to offset temperature values generated at 0.15 wt%, 0.25 wt%, 0.55 wt%, 0.65 wt% graphene-reinforced alumina ceramic tool inserts, as well as pure alumina tool inserts.

Effect of grain growth in bimodal microstructure on cutting performance of self-toughening Dy-α-SiAlON ceramic tool inserts

Although significant increase in mechanical properties has been achieved in ?-SiAlON ceramics by introducing self-toughening bimodal microstructure, the bimodal microstructure may not always result in better cutting performance of ?-SiAlON tool inserts. Herein Dy-?-SiAlON ceramics were prepared by hot-pressing at 1900?C under 30MPa. Diameter and aspect ratio of the large elongated ?-SiAlON grains pivotal to formation of bimodal microstructures were regulated by using 0-5wt.% Dy2O3 as a sintering additive. Mechanical properties and cutting performance of ?-SiAlON tool inserts were evaluated. The results showed good Vickers hardness (19.0-19.7GPa) and fracture toughness (3.61-4.18MPa?m1/2) increasing with crack propagation length. However, transverse section of the large elongated grains was revealed as critical crack to cause premature fracture of the ?-SiAlON ceramics. Fracture rather than attrition wear was recognized as dominant mechanism for tool failure, indicating that for better cutting performance of the ?-SiAlON tool inserts a selftoughening microstructure consisting of thinner grains with large aspect ratio is required.

Analysis and prediction of tool wear in dry turning of hardened D3 steel using hybrid insert: A novel wear map approach

Previously cubic boron nitride (CBN) and ceramic inserts were used for the dry turning of heat-treated D3 tool steel with cutting speed beyond 200 m/min, suffers from severe tool wear and generation of high temperature at the interface. To overcome these shortcomings, a hybrid ceramic insert that is, Al2O3 + Ti (C,N) with coated (TiN) is used in dry turning of D3 tool steel (heat-treated). Use of the hybrid insert with a lower feed rate (0.04 mm/rev) and a minimum depth of cut (0.4 mm) improves the surface quality of the turning process by significantly reducing the tool wear and cutting forces requirement in a cutting speed range of 165– 175 m/min. Even though ceramic tool inserts have high wear resistance at elevated temperatures but it has limited impact strength. So, ceramics is only recommended for shocks and vibration-free high-speed cutting operations of hardened steel under a dry environment. The novelty of this article is the development of a wear map for the analysis and prediction of tool wear. The Scanning electron microscope studies of wear region elucidate that low tool wear that the predominant modes of wear for low tool wear cutting conditions are delamination and abrasion. Besides for higher tool wear the prevailing wear mode is a combination of abrasion as well as adhesion wear. It is perceived that our proposed methodology outperforms the state-of-the-art methods.

Particle Swarm Optimization and Machinability Aspects during Turning of Hardened D3 Steel

Metal cutting processes are associated with excessive forces, friction and heat generation due to continuous intensive contact between the active cutting tools and the work which degrades the machined surface quality. The hardened tool steel having excellent wear resistance property receives an extensive promotion, investigation and application in the die manufacturing industries. In this research, the machinability of hardened AISI D3 tool steel has been investigated using TiN-coated Al2[Formula: see text](C,N) ceramic tool inserts as per Taguchi’s [Formula: see text] orthogonal design of experiments is in horizontal turning under the dry condition. The experimental dataset was used for the regression model development of primary process outputs as well as mean cutting force using the response surface methodology (RSM) which was found to be significant. The parametric interaction effects on each process output were studied along with with chip morphology in detail. The cutting force as well as material removal rate was found to be significantly influenced by depth of cut, whereas machined surface quality was primarily dependent on tool feed rate. The wider with less prominent saw tooth chips got changed to narrower saw-tooth form with intensive shear bands at higher feed rates. Finally, an attempt has been made to develop an optimal parametric setting using particle swarm optimization technique to achieve minimum surface roughness and maximum material removal rate at less cutting force. The optimal parametric setting was high cutting speed (308[Formula: see text]m/min), high tool feed rate (0.08[Formula: see text]mm/rev) with medium depth of cut (0.6[Formula: see text]mm) to achieve each objective. This evolutionary particle swarm optimization technique was found to be highly accurate (within 8% error) as per validation experiment.

Machinability investigation and sustainability assessment in FDHT with coated ceramic tool

The paper addresses contribution to the modeling and optimization of major machinability parameters (cutting force, surface roughness, and tool wear) in finish dry hard turning (FDHT) for machinability evaluation of hardened AISI grade die steel D3 with PVD-TiN coated (Al2O3–TiCN) mixed ceramic tool insert. The turning trials are performed based on Taguchi\'s L18 orthogonal array design of experiments for the development of regression model as well as adequate model prediction by considering tool approach angle, nose radius, cutting speed, feed rate, and depth of cut as major machining parameters. The models or correlations are developed by employing multiple regression analysis (MRA). In addition, statistical technique (response surface methodology) followed by computational approaches (genetic algorithm and particle swarm optimization) have been employed for multiple response optimization. Thereafter, the effectiveness of proposed three (RSM, GA, PSO) optimization techniques are evaluated by confirmation test and subsequently the best optimization results have been used for estimation of energy consumption which includes savings of carbon footprint towards green machining and for tool life estimation followed by cost analysis to justify the economic feasibility of PVD-TiN coated Al2O3+TiCN mixed ceramic tool in FDHT operation. Finally, estimation of energy savings, economic analysis, and sustainability assessment are performed by employing carbon footprint analysis, Gilbert approach, and Pugh matrix, respectively. Novelty aspects, the present work: (i) contributes to practical industrial application of finish hard turning for the shaft and die makers to select the optimum cutting conditions in a range of hardness of 45-60 HRC, (ii) demonstrates the replacement of expensive, time-consuming conventional cylindrical grinding process and proposes the alternative of costlier CBN tool by utilizing ceramic tool in hard turning processes considering technological, economical and ecological aspects, which are helpful and efficient from industrial point of view, (iii) provides environment friendliness, cleaner production for machining of hardened steels, (iv) helps to improve the desirable machinability characteristics, and (v) serves as a knowledge for the development of a common language for sustainable manufacturing in both research field and industrial practice.

Uporedna analiza procesnih parametara kod habanja umetaka za alat sa i bez premaza pri obradi legure Hastelloy C-276

Machining is the most significant process for any manufacturing company to improve the quality of the finished component. The objective of this article is to analyse the process performance of Hastelloy C-276 using PVD (Physical Vapour Deposition) coated, uncoated and alumina-based ceramic tool inserts of high grade quality. Turning process was performed on NC (Numerical Control) machine by varying RPM, feed rate and depth of cut based on the Taguchi L9 orthogonal array approach. In this study, crank wear, flank wear, nose wear, SR (Surface Roughness), MRR (Material Removal Rate), tool temperature and feed force are examined during machining of hardened material and simultaneously static structural analysis of the tool insert along with the tool holder was performed using ANSYS mechanical. This research investigation helps in determining appropriate parameters with varied coated inserts to make the process easier, efficient and economical.

Study of tribofilms generation at different cutting speeds in dry machining hardened AISI T1 and AISI D2 steel

Hard dry machining of AISI T1 and AISI D2 steels at comparable hardness (around 59 HRC) were performed at 50 m/min, 80 m/min and 100 m/min cutting speeds separately with uncoated alumina ceramic tool inserts (Al2O3 + TiC), in order to study the effect of cutting conditions on the generation of tribofilms. Comprehensive assessment of uncoated ceramic inserts in machining of T1 and D2 at different cutting speeds was made by optical microscope, scanning electron microscope and X-ray photoelectron spectroscopy. It was shown that higher cutting speeds increased the formation of thermal protective and/or lubricating tribofilms. In machining D2 steel, more intensive formation of Cr-O tribo-oxides brought a lower wear rate; while in cutting T1 steel, a higher amount of W-O tribofilms generation provided better lubrication. At higher cutting speeds, wear/friction behaviour changes were attributed to differences in two factors: first, from a traditional micro-scale standpoint, the distribution of carbide within steels and the accumulation of thermal and mechanical damages during different cutting conditions; second, from a new nano-scale viewpoint, the generation of protective/lubricating tribofilms due to change of machining conditions.

Experimental comparison of PVD, CVD and CERAMIC tool inserts in turning of hardened EN 19/AISI 4140 for optimization of surface roughness and material removal rate

Experimental comparison of PVD, CVD and CERAMIC tool inserts in turning of hardened EN 19/AISI 4140 for optimization of surface roughness and material removal rate

The viability of microwave sintering process to produce a ceramic tool insert

The viability of microwave sintering process to produce a ceramic tool insert

Use of Ceramic Tools in Hard Turning of Hardened AISI M2 Steel

Tool wear and machining performance of hardened AISI M2 steel in hard turning has been studied. Ceramic tools were used in the cutting tests without coolants, and the workpiece was heat treated to increase its hardness up to Re 60. Cutting forces, temperature, and tool wear were measured in the experiments and the effects of cutting conditions on these were investigated. Important aspects from the research are summarized as follows: 1. Flank wear was the dominant wear mode on the ceramic tool insert in hard turning. In contrast, crater wear was very small due to the ceramics high resistance against chemical reactions at high temperature. A notch was unlikely to be formed in the tool. 2. The initial flank wear rate mainly depends on the feed rate. High feed rates cause a high initial flank wear rate. 3. Depth of cut was the most important cutting parameter to affect cutting force variation, and the cutting force increased due to tool wear. Presented at the 54th Annual Meeting Las Vegas, Nevada May 23–27, 1999

Evaluation of advanced alumina-based ceramic tool inserts when machining high-tensile steel

Three types of alumina-based ceramic tools (zirconia toughened, titanium-carbide reinforced and silicon-carbide-whisker reinforced) were used to evaluate their cutting performance when machining a high-tensile steel. Experimental studies were carried out at various cutting speeds, feeds and depths of cut, in dry conditions. The cutting performance of the alumina-based ceramic tools was judged by the cutting force produced during the process of machining, by the surface roughness of the workpiece and by the wear rate of the cutting inserts. The influence of the cutting parameters (that is, the cutting speed, feed rate and depth of cut) on the cutting performance is discussed.

WEAR OF CERAMIC TOOLS WHEN MACHINING CAST IRON

ABSTRACT Five commercially available ceramic tool inserts were used for studying the machining characteristics of grey cast iron. These inserts from three suppliers were shown to behave as two groups. The first group containing Al203 and Al203/Zr02 showed low wear rates over a wide range of cutting speeds and these wear rates were essentially speed independent. This group showed considerable fracture tendency in the speed range 250m/min - 500 m/min. Alumina tools containing TiC/TiN showed higher wear rates which were both speed and TiC content dependant. High TiC content tools demonstrated high wear rates at low speeds and vice versa. TiN appeared to have little, if any, effect on wear rate. The presence of TiC and TiN also appeared to suppress the fracture tendency in the speed range 250m/min - 500 m/min.