Tool Material Research Articles

The Influence of Deep Drawing Parameters on Stresses and Strains in Drawing Tools in the Context of their Durability and Process Load

This publication presents the influence of selected parameters in the deep drawing process on the energy consumption of the entire process. It was analysed how die clearance and the radius of the rounded working edge of the die affect drawing force and work. Modifying these parameters does not directly affect the geometry of the finished stamped product. In addition, it was analysed how modifying the clearance and the radius of the rounding of the working edge of the die affects the magnitudes of stresses and strains in the tools, i.e. the punch and the die. The study was carried out numerically using Ansys Ls-Dyna software. An elastic-plastic model with isotropic hardening was used to model the tools without considering strain rate. This approach makes it possible to assess how a given process will affect the abrasive wear of the working surfaces of the die and punches when the yield stress in the tool material is exceeded. A significant increase in tool life was observed through a reduction in plastic deformation when using clearances greater than the thickness of the sheet metal. Using a larger die edge rounding radius also positively affected tool life, maximum drawing force, and total work.

PROGRESS AND CHALLENGES IN PLUNGE MILLING: A REVIEW OF CURRENT PRACTICES AND FUTURE DIRECTIONS

This review examines recent advancements and ongoing challenges in plunge milling. It is an increasingly utilised machining process renowned for its high material removal rates, particularly with hard-to-machine materials like hardened steels and titanium alloys. Plunge milling’s unique perpendicular tool path offers enhanced stability and reduced lateral cutting forces, making it valuable for applications that demand precision and efficiency, such as aerospace and automotive manufacturing. The paper systematically analyses and synthesises research on critical areas of plunge milling optimization, including tool geometry, material selection, coating technologies, and process parameters, highlighting strategies to mitigate common issues like rapid tool wear and chip evacuation difficulties. In this comprehensive overview, the review introduces theoretical and experimental findings on optimizing plunge milling tools and process parameters—such as cutting speed, feed rate, and coolant delivery—that are essential for improving performance and achieving desirable surface finishes. The paper also explores innovative trends, including AI-driven optimization algorithms and hybrid machining systems, which hold promise for addressing persistent limitations and enhancing plunge milling’s industrial applicability. By consolidating findings from recent studies, this review contributes to a deeper understanding of plunge milling’s role in high-precision manufacturing and identifies future research directions for advancing the process. The insights presented offer practical and strategic implications, aiming to guide ongoing developments in plunge milling technology and its adoption across various precision-oriented industries.

THE INFLUENCE OF DIFFERENT HARDNESS OF THE TOOL MATERIAL ON THE WEAR OF SHM GRINDING WHEELS AND THE SPECIFIC ENERGY INTENSITY OF GRINDING

It was established that conditionally viscous-brittle tool materials (high-speed steels and hard alloys) behave in the same way with an increase in hardness: wheel wear and the specific energy consumption of their grinding decrease. As the hardness of brittle tool oxide-carbide ceramics increases, both wheel wear and the specific energy consumption of grinding, on the contrary, increase. That is, an increase in the hardness of viscous-brittle materials facilitates the separation of elementary chips, less energy is needed for this, and accordingly the wear of the wheel and the specific energy consumption of their grinding are reduced. On brittle ceramics, with increasing hardness, there is no change in chip removal, but harder sludge becomes more abrasive and, as a result, the wear of the wheel and the specific energy consumption of their grinding increase. The conclusion from the literature that hard and less plastic materials require relatively less specific energy for grinding is confirmed by us when comparing materials of approximately the same hardness - hard alloys and ceramics. In ceramics, the energy consumption of grinding is actually four times lower than that of hard alloys.

ASSESSMENT OF THE ROOT MEAN SQUARE DEVIATION ON SURFACES MACHINED BY HIGH-FEED TANGENTIAL TURNING

Recent advancements in machining focus on precision, efficiency, and handling harder materials, driven by sectors like aerospace and automotive. Hard machining, or processing materials over 45 HRC, presents challenges such as rapid tool wear, intense heat, and maintaining dimensional accuracy. Innovations in cutting tool materials and CNC technology have improved these processes, but tool degradation and high forces still complicate machining hardened materials. Surface roughness is a key quality metric, impacting performance factors like wear resistance and fatigue life. By optimizing cutting parameters, manufacturers aim to achieve consistent surface finishes, essential for durability in demanding applications. In this paper, the effect of the input parameters (depth of cut, feed, and cutting speed) are analysed on selected surface roughness parameters. The setup parameters were selected according to the full factorial design of experiment method. The results showed that higher feed rates resulted in rougher finishes, leading to greater spacing between profile elements and steeper surface profiles in the studied range.

Effect of diamond grain size on mechanical properties and cutting performance of PCD tool in milling of Cf/SiC composites

The polycrystalline diamond (PCD) tools have excellent cutting performance in machining composites. However, the tool wear mechanism of PCD tools in milling Cf/SiC composites remains unclear. There are few researches on the effect of diamond grain size on the cutting performance of PCD tools and material removal mechanism. In this paper, four PCD samples with different grain sizes were prepared under high-temperature and high-pressure condition. The microstructure, flexural strength, and cutting performance of PCD samples was tested. The wear mechanism of the tools was analyzed by observing the wear morphology of the front and rear cutting surfaces of the PCD tools. The influence of diamond grain size on the cutting performance of PCD tools was investigated in terms of tool life, surface roughness and material removal mechanism. The results indicated that the highest bending strength was found in the PCD sample with the grain size of 5 μm, as the diamond grain size increased, the bending strength of the PCD tool decreased. Tool failure was caused by fiber bundles and chip dust scratching the binder and diamond grains. In the same cutting distance, due to the difference in bonding between diamonds of different grain sizes. The 2 μm~30 μm grain size of the PCD tool wear was the slowest, 5 μm grain size of the fastest PCD tool wear. As the grain size decreased, the machined surface quality of Cf/SiC composites improved. The fiber removal mechanisms employed the gradual transition from shear removal to bending removal as the grain size increased.

Effects of Cutting Parameters on Tool Wear in Milling Inconel 625 Superalloys with a SiAlON Ceramic and the Prediction of Tool Life

Inconel 625 superalloys are widely preferred in various industries because of their superior mechanical properties at high temperatures. The superior properties they exhibit make the machinability of Inconel 625 alloys difficult. This situation can cause rapid wear of the cutting tools, making the cutting tool unusable in very short periods of time and causing deterioration of the workpiece surface quality. Therefore, improving the machining performance of Inconel 625 alloys, optimizing the machining parameters and using the optimum cutting tool material and geometry are important. In this study, SiAlON ceramic cutting tools, which have been widely used in recent years, were preferred. SiAlON tools supplied in raw rod form were subjected to various processes and finalized into final products. The effects of three different cutting speeds (vc), feed rates (f) and axial depth of cut (ap) on tool life (T), wear patterns and mechanisms were investigated with 9 tests designed according to the Taguchi L9 orthogonal array. The results revealed that the f values, the effects of which were analysed, had the most significant effect on T. By performing regression analysis with T values, the coefficients used in the extended Taylor T equation were determined, and T predictions were obtained. The regression model was found to be consistent with the experimental results, with an effect of 99.34%, and the model was significant according to analysis of variance. The predominant wear patterns of the cutting tools were flaking at a low vc, nose collapse at a high vc and an adhered workpiece under all conditions. The wear mechanism was found to be predominantly adhesion and fracture. The presence of Ni, Cr, Mo, Nb and Fe on the cutting tool surface was determined, and the effect of the concentrations was observed to increase/decrease significantly depending on the parameter values examined.

The generation mechanism of cutting heat and the theoretical prediction model for temperature on the rake face of the cutting tool in Zirconia ceramics

Cutting temperature and its distribution are crucial factors influencing tool strength and wear rate, due to the hardness and brittleness of Zirconia (ZrO2) ceramics, significant challenges arise in both direct temperature measurement in the cutting zone and theoretical analysis of cutting heat. Thus, focusing on the turning characteristics of ZrO2 ceramics, this study analyzes the mechanism of cutting heat generation and proposes utilizing thermodynamic state equations to determine the cutting heat source on rake face of tool. Based on the heat source method, a theoretically prediction model for temperature distribution on rake face is established. This model considers primary cutting parameters, workpiece material properties, crack fracture characteristics of the machined surface, and thermal characterizations of the tool material. The relationship between tool wear and cutting temperature is experimentally analyzed to determine the characteristic temperature that indicates the initial stage of tool wear. The validity of the theoretical model is verified, as the predicted results show high consistency with experimental results within the range of experimental parameters, with a relative error within 15.2 %.The results reveal the highest temperature during brittle cutting occurs within the cutting layer area, with the highest temperature occurring approximately 50 μm from the tool tip, followed by a gradual decrease beyond 150-200 μm. This study also demonstrates that cutting heat in ceramic turning does not solely originate from friction heat between tool flank-workpiece but also includes impact heat from tool rake face-workpiece, which under certain cutting parameters exerts a more significant influence on cutting temperature. This model can facilitate the selection and optimization of cutting process parameters for brittle materials and provide a theoretical basis for analyzing the relationship between tool thermal damage, thermophysical properties, and tool wear.

Research status of cutting machining NiTi shape memory alloys: a comprehensive review

NiTi shape memory alloys (SMA) have garnered significant interest owing to their shape memory effect, superior corosion resistance, and biocompatibility. This paper reviewed the current research status of cutting machining for NiTi SMA, focusing on turning, milling, and drilling processes, emphasizing the influence of various cutting parameters, tool materials, and cooling methods on machining performance. The optimal turning effect under dry cutting circumstances is achieved when the cutting speed surpasses 100 m/min. The application of Minimum Quantity Lubrication (MQL) in milling, alongside the use of cold air and the optimization of parameters such as feed rate and cutting depth, could diminish cutting force and temperature, thus reducing burr formation. Cemented carbide and high-speed steel covered with TiN are the ideal materials for drilling tools, and the use of substantial cutting fluid yields superior cutting performance compared to MQL. This review concludes that, despite advancements in the study of machining NiTi shape memory alloys, further research is necessary to enhance the efficiency and quality of NiTi SMA machining, particularly with tool material selection and cooling techniques. Finally, based on the current research results, this paper proposes possible future research directions, which provides valuable theoretical guidance for the processing research of NiTi SMA.

Toughening mechanisms taking into account growth kinetics of SiC whiskers for bionic ceramic cutting tool materials

The growth mechanism and kinetic characteristics of SiC whiskers for novel bionic ceramic cutting tools were analyzed by modified Arrhenius equation, which reveals the regulation effect of SiC whisker growth on the microstructure evolution. Furthermore, the influence of the growth mechanism on the toughening mechanism under shear and indentation failure was investigated. The results showed that the formed transition area at the bonding interface can improve the residual thermal stress distribution. The synergistic effect of multiple macro/micro-toughening mechanisms and interfacial strengthening mechanisms enabled the bionic ceramic cutting tool materials to exhibit excellent fracture resistance under shear and indentation failure.

Investigation of tool wear behavior in CFRP drilling by using different tool materials

Abstract The industrial usage of Carbon fiber reinforced polymers (CFRP) has increased significantly over the past few years due to its distinguished characteristics like great strength-to-weight ratio, fatigue resistance, superior damage tolerance, excellent corrosion resistance, etc. Machining of CFRP differs from traditional machining due to its structure. This experimental study aims to investigate the effect of drill bit material on tool wear and to optimize the material selection process of twist drill bits during CNC drilling of CFRP regarding the output of tool wear, thrust forces, and torque generated during the drilling process. Four twist drill bits with dissimilar materials (i.e., HSS-4341, HSS-M2, HSS-Co, and Tungsten Carbide) having the same size and diameter (3mm) were selected and used for CNC drilling on CFRP plates. During the drilling process, thrust forces and torque were calculated with the help of a dynamometer for each drilled hole. Moreover, the tool wear was seen and compared after the 1st hole and 20th hole for each drill bit to analyze the behavior of different tool materials toward CFRP machining. The results showed that Tungsten Carbide is the most suitable tool material for CFRP drilling as it yielded the lowest thrust forces and lowest torque for all 20 holes. Moreover, the Tungsten Carbide had the lowest tool wear among all the drill bits. These results imply that tool life can be significantly elevated if Tungsten Carbide is to be used for machining of CFRP.

Comparative study and experimental validation of cutting forces in high-speed ball-end milling for AL 7075-T6 and AL 6061-T6 alloys

This study examines the importance of precise cutting force prediction during high-speed ball-end milling of the AL 7075-T6 and AL 6061-T6 aluminum alloys, which are widely used in the aerospace and automotive industries, because to their strength and fatigue resistance. Predicting cutting forces is critical for optimizing milling conditions and creating high-quality surfaces. We have used a mechanistic model to estimate cutting forces based on experimental data. To generate the more precise predictions, the developed model takes into account tool geometry, cutting settings and material properties. We have measure the cutting forces on a CNC SOMAB DIAM 850 milling machine by using a Kistler 9257A dynamometer. We have done simulations with MATLAB software. The results reveal that the mechanistic model accurately predicts both alloys. ALU 7075-T6 produces higher cutting forces because to its increased strength. This comparative research demonstrates that the mechanistic approach is useful in forecasting cutting forces in high-speed ball-end milling of aluminum alloys, providing useful insights for improving machining operations.

Use of osseous materials during the Chalcolithic in Northeastern Bulgaria (based on materials of Polyanitsa tell)

Many Chalcolithic cultures of the Balkan-Danube region used antler, animal bones, boar tusks and shells as raw materials for tools, household and votive items, as well as jewelry. The unique collection of such objects found in 1973–1974 during the archaeological study of the Polyanitsa tell (Northeastern Bulgaria), is particularly numerous and diverse (266 items). Experimental and traceological studies of part of this collection made it possible to characterize the manufacturing technology of these products, as well as the functional purpose of many of them. Among the industrial equipment, tools were found that were used in agriculture, processing flint, wood, hides and skins, and ceramics. It should be noted that some flint tools, found at the settlement, were used for processing bone/antler. This fact, as well as finds of blanks and unfinished items made of bone/antler, indicate their local production. The quality and the wide range of products of the bone processing industry serve as proof of the high level of its development and demand for such utensils in the economic and domestic activities of the population of the Chalcolithic sites of Northeastern Bulgaria.

Shape design optimization of a flat endmill tool

AbstractAmong the many possible metal‐cutting processes, milling is regarded as one of the most widely applied processes to machine different engineering materials productively. During the milling process, there is relative motion between the endmill tool and the workpiece. Energy is required to drive the cutting force used by the tool in separating the chips from the workpiece. Several studies have focused on the effects of milling process parameters on the cutting force, for instance by varying the cutting parameters, machining properties and the extent of cooling/lubrication. Other studies have explored the influence of tool geometry and material properties on the cutting force. Results from these studies have brought about improvements in the design of milling machinery and tools. The current study presents a novel automated approach for tool geometry optimization which is fully coded in Matlab. An automated and parametrized endmill design procedure was created featuring input parameters such as rake angle, relief angle, clearance angle and helix angle, all of which have been shown, through numerous studies, to influence cutting forces. The parameters were here used to generate the shape profile for one cutting edge of a flat endmill. This cutting edge profile is next copied and rotated, as per the design's pitch angle, to form the complete set of cutting flutes for the flat endmill. Next, the surface defined by the completed profile is meshed using quadrilateral elements. The 3D endmill design is then formed by extruding, and twisting as per the helix angle, this quadrilateral mesh to form a solid hexahedral mesh. Finally, an automated iterative optimization process was defined, featuring the above parametrized design process coupled with Abaqus‐based finite element simulation of the milling process. The expected result is that the proposed optimization procedure will be able to identify the endmill design parameters which minimize the cutting force. At the completion of the optimization, a minimized maximum resultant cutting force value is obtained from using the newly optimized endmill. The resultant cutting force was reduced by 17.6%. It is anticipated that the automated design, meshing and simulation‐driven optimization approach is generalizable to other tool design variations.

Research Progress towards the Machining of Titanium Alloy Using CNC Milling: A Technical Review

Because of their extraordinary qualities, titanium alloys are very sought-after materials that can be applied to a wide range of sectors. Excellent mechanical and chemical qualities, including a high strength-to-weight ratio and resistance to corrosion, are present in it. The special properties of these alloys make machining them extremely difficult. As frequent tool wear occurs throughout the machining process, Computer Numerical Control (CNC) milling has become a potential method for machining titanium alloys due to its precision and versatility. This review article provides a comprehensive overview of the development of titanium alloy CNC milling, with an emphasis on the effects of cutting tool geometries and materials on machining efficiency. The process examines several aspects of cutting circumstances, including depth of cut, speed, feed rate, and lubrication techniques, and optimizes machining parameters and procedures to achieve the best results. Surface integrity and quality, surface roughness, residual stresses, and microstructural changes brought about by CNC milling are the main points of evaluation.

The influences of alloying elements and processing conditions on the machinability of wrought aluminium alloys: A literature review

Today, wrought aluminium alloys are ranked among the most important materials with low specific density, strength features, corrosion resistance, machinability and recyclability properties in numerous application fields. Machining process of these alloys involves a number of considerations to ensure the highest quality and productivity. Key machinability issues include the rate of tool wear, workpiece surface finish and integrity and machining process sustainability. Understanding and optimising these parameters can lead to improving the machinability, better surface finish, longer tool life, and overall, more efficient and cost-effective machining processes for wrought aluminium alloys. The machining of wrought aluminium alloys remains a challenging task due to their unique characteristics, such as high strength, thermal conductivity and refined grain structures with mechanical and/or heat treatment. Although considerable progress has been made in the development of cutting tool materials and machining techniques for wrought aluminium alloys, further research is required to improve the machinability of these materials and reduce the associated costs and time needed for production. Having access to relevant information about these characteristics can help industries and researchers make informed decisions and achieve better outcomes when machining of these important materials. Accordingly, in the current research work, a comprehensive study has been carried out on machining of wrought aluminium from different points of view.

Development of two-layer whisker-reinforced PcBN materials for cutting tool applications

This study investigates the polycrystalline cubic boron nitride (PcBN) tool materials with a TiN-Zr based binder without additives (BTZ base material) and with whisker additives (SiCw, Al2O3w, Mg2B2O5w) obtained via high-pressure high-temperature (HPHT) sintering at 7.7 GPa and 2000 °C. The whiskers reinforced composite compacts were produced both in one- and two-layer (sandwich-type) forms. The phase composition, microstructure, physical-mechanical properties and cutting performance of the composite compacts were analysed. The results demonstrate that reinforcing with SiCw leads to the formation of BTZ+SiCw composites with a homogeneous microstructure, high hardness, and Young's modulus, enabling the manufacture of one-layer cutting inserts with an extended tool life of up to 11 min when turning Inconel 718 alloy. Similarly, the BTZ+Al2O3w one-layer material, despite exhibiting slightly lower hardness compared to BTZ+SiCw, still displayed satisfactory wear resistance with a tool life of up to 7 min. Notably, the two-layer (sandwich type) s1: BTZ+SiCw/BTZ+Al2O3w composite cutting inserts exhibited the highest durability, with a tool life of up to 13 min when tested on the SiCw-reinforced side and 8 min on the Al2O3w-reinforced side. In contrast, the BTZ+Mg2B2O5w composite was found unsuitable as a working tool component but shows promise as a substrate layer in two-layer configurations. The study indicates the potential for further development of whisker-reinforced two-layer composite PcBN materials to enhance tool performance and longevity.

Performance analysis of turning operation parameters empirically on Delrin

Delrin is the best additional material for metals because of its inherent qualities, such as great wear resistance and tensile strength. The main aim of this work is to investigate how independent variables like feed rate, spindle speed, and depth of cut are significant for dependent variables such as surface roughness, temperature, stresses, and material removal rate on novel material Delrin. The independent variable ranges are selected based on tool and workpiece material combinations and machine tool specification as spindle speed 230 – 844 rpm, feed rate 0.5 – 1.5 mm/rev, and depth of cut 1 – 3 mm. Based on the L27 orthogonal array experimental plan 27 numbers of experiments are conducted by the design of experiment concepts. The theoretical investigation through response surface methodology is also conducted to establish how independent variables affected dependent variables when Delrin was being machined. The independent variable's significance is determined by the ANOVA table for all the considered responses. In addition to the considered flow of work, the experiential model is developed by the utilization of regression analysis. The developed models are confirmed by experimental data and the models have the best validation results with the experimental results.

Performance analysis of uncoated and coated (TiN-, TiAlN-) carbide drills in drilling graphene-reinforced GF/epoxy nanocomposites: Analytical and experimental study

The present study aims to investigate the performance of conventional uncoated and coated (TiN, TiAlN) solid carbide drill tools in drilling bi-directional graphene-reinforced (2 wt.%) glass fiber (GF)/epoxy polymer nanocomposite laminate with two distinct lamination schemes ([0/90]12S and [0/90/±45]6S). Performance measures included thrust force, torque, tool flank wear, peak acoustic emission, root mean square (RMS) of acoustic energy, and average surface roughness. Moreover, the delamination that occurs beyond the critical value of thrust force (computed analytically) has also been addressed. Optimized drilling parameters were used for experimentation to minimize thrust force and torque simultaneously. Both TiN and TiAlN-coated carbide drills outperformed uncoated carbide drills for fewer holes (around 25 for TiN and about 40 for TiAlN), but their performance deteriorated with more holes due to coating chipping or peeling from the original tool material. The (0/90 ± 45)6S graphene-reinforced layup showed less tool wear, deterioration, and acoustic emission energy compared to the (0/90)12S neat layup. TiAlN-coated drills exhibited the smallest wear on the flank face followed by TiN-coated and uncoated carbide drills. Moreover, the smoothest cut surface throughout the 300 holes drilled, averaging 1.5 µm to 1.8 µm in surface roughness, was observed with the TiAlN-coated drill. Therefore, the TiAlN-coated drill is recommended for drilling a larger number of holes due to its reduced tool wear, smoother cut surfaces, and better form accuracy with minimal delamination.

Supplemental Material for A Clinician-Based Treatment Fidelity Tool for PRIDE in All Who Served

Supplemental Material for A Clinician-Based Treatment Fidelity Tool for PRIDE in All Who Served

FeSi-NiAl composite as a future tool material

Composite materials based on NiAl matrix and FeSi reinforcement are tested as potential tool materials in this work. The components (FeSi, NiAl) were prepared by mechanical alloying separately, blended and consolidated by spark plasma sintering method. The results showed that the composite blend can be successfully sintered at 1000 °C. Thermodynamic calculations were performed in SW Thermo-Calc, ver. 2019a for obtaining the phase diagrams of the studied systems. The composite has the hardness almost comparable with the heat-treated cold work tool steels. The hardness increases with the growing amount of silicide in the mixture. The same trend can be slightly visible also in wear resistance and the results nearly reach the performance of high-grade cold-work tool steels but having lower friction coefficient. The ultimate compressive strength reached values of 1830–2640 MPa, depending on chemical composition. The result indicate that these materials could reach the performance of the high grades of tool steel, but without the need for any heat treatment, which makes them to be a really promising eco-friendly alternative.