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In this paper, experimental analysis was performed during micro-electrical discharge machining (micro-EDM) of titanium alloy Ti–6Al–4V (grade 5) using three types of tools viz. copper (Cu) tool, tungsten carbide (WC) tool, and synthetic graphite (Gr) grade three tool. The main process parameters were taken as (a) pulse on time ( T on ), (b) pulse off time ( T off ), (c) voltage (V), and (d) capacitance (C). The output responses were taken as the material removal rate (MRR) and tool wear rate (TWR). Taguchi method coupled with grey relational analysis (GRA) (L 1 6 orthogonal array) technique was applied to optimize the input process parameters for both the responses. Scanning electron microscopy (SEM) analysis of the workpiece and tool was also performed to investigate the morphology of the machined surface and tool surface. Energy-dispersive spectroscopy (EDS) analysis was performed to investigate the elemental composition of the machined surface. The experimental finding reveals that tungsten carbide is the most suitable tool material for machining the chosen workpiece for obtaining optimal MRR and TWR. The optimum condition for the copper tool was found as 180 V, 1000 pf, 10 μ s ( T on ), and 10 μ s ( T off ). Meanwhile, the optimum parametric condition for tungsten carbide and graphite tools was found to be the same as 240 V, 100 pf, 20 μ s ( T on ), and 5 μ s ( T off ). [ABSTRACT FROM AUTHOR]

The study aims to fill the gap in the existing literature by investigating the effects of various tool materials, including copper, tungsten carbide, and brass, on performance parameters in electric discharge machining (EDM) simulations. The authors developed a modified gaussian heat flux equation that incorporates the electrical resistivity of both the tool and workpiece, based on prior experimental investigations. The authors further developed a finite element model that incorporates the modified Gaussian heat flux equation, spark radius, and fraction of heat transferred to workpiece as a function of pulse on time and pulse current, latent heat, specific heat values, and thermal conductivity properties. The outcomes of the simulation indicated that the Cu tool exhibited the minimum MRR and SR values when subjected to a current of 9 amps and a duty cycle of 0.4, as well as a current of 12 amps and a duty cycle of 0.6. The results also indicate that the brass tool displayed marginally elevated MRR and SR, whereas the Tungsten carbide tool exhibited the highest MRR and SR. The simulation results for all three tool materials showed similar trends, consistent with prior research. Also, an increase in gap voltage, pulse current and duty cycle was observed to correspond with increased MRR and SR. Authors also observed that as electrode material electrical conductivity increased, so did workpiece material residual stresses. These results assist with the choice of tool materials for EDM processes, allowing for finer control over performance parameters and greater machining efficiency. [ABSTRACT FROM AUTHOR]

α/β‐SiAlON/SiC composite ceramic tool materials were prepared via spark plasma sintering. The effects of content and size of SiC particles and sintering temperature on phase composition, mechanical properties, and microstructure were investigated. The results indicated that SiC restrained the transformation of β‐SiAlON to α‐SiAlON, but higher SiC content (≥10 wt.%) resulted in a higher Vickers hardness of the composite. The large size of SiC particles raised the densification temperature of α/β‐SiAlON composites, and small SiC particles benefited to improve microstructure. There were more equiaxed α‐SiAlON grains and β‐SiAlON with a larger aspect ratio (α¯95$\bar{\alpha}_{95}$ = 5.1) in the α/β‐SiAlON composite containing 100 nm SiC. The sample containing 10 wt.% 100 nm SiC particles sintered at 1700°C had the optimal properties with a Vickers hardness and fracture toughness of 18.5 ±.2 GPa, 6.4 ±.2 MPa m1/2, respectively. [ABSTRACT FROM AUTHOR]

Hybrid laminates made of Carbon Fibre and Glass Fibre Reinforcement have become widely popular in various applications which are mainly due to their excellent structural strength coupled with lower cost. In all these applications, drilling plays a crucial role during the assembly of these structural components. This paper deals with the examination of the influencing parameters (feed rate, tool material) on thrust force during drilling of hybrid laminates. Statistical Design of Experiments has been used for the analysis of the drilling parameters on the thrust force. Taguchi's L9 (32) array has been used to determine whether the response function is minimised by feed rate or tool material. Hole drilling on hybrid FRP laminate has been done using Solid Tungsten Carbide and High-Speed Steel tool material under controlled machining operations. The results reveal that the tool material has a higher influential effect on the thrust force when compared with the feed rate. Also, the morphology of hybrid laminate was obtained using a Scanning Electron Microscope (SEM) and the results indicate that surface texture was observed to be optimum. [ABSTRACT FROM AUTHOR]

A novel ceramic coating-like (CCL) structure was proposed for preparing a potential ceramic cutting tool material. The influence of critical factors, including the material composition, composition content and surface layer thickness, on the residual stress was analyzed by the finite element method (FEM). Under the condition of the optimized parameters, the compressive stress generated on the surface layer of the CCL tool material ranged from −163 MPa to −248 MPa. Based on the obtained results, a (Ti,W)C/Al 2 O 3 +SiC CCL tool material was prepared by vacuum hot-pressing sintering, indicating the residual compressive stress (−122.3 MPa) of the surface layer. Compared with the performance of homogeneous cermet materials, the surface hardness and flexural strength of the CCL tool materials were increased by 46.58% and 37.76%, respectively. Moreover, the SEM imaging results of the sample surface and fracture morphology and the energy dispersive spectroscopy (EDS) analysis results showed that the dense ceramic surface and phase interfacial transition layer were formed with a uniform gradient distribution and without defects. [ABSTRACT FROM AUTHOR]

The use of the multi-spindle head in drilling technology can reduce the drilling cycle time by simultaneously producing multiple holes in one go. However, selecting the appropriate drill material and geometry is critical to overcoming the challenges of multi-hole drilling to ensure high-quality holes. This study investigates the use of the multi-spindle head with different tool configuration, tool materials and tool geometry during multi-hole simultaneous drilling of Al2024. A comparison is made among the high-speed steel drills (diameter: 6 mm; point angle: 118°) and two different carbide drills (diameter: 6 mm and 10 mm; point angle: 140°) as well as the maximum and minimum possible centre to centre tool distances of the multi-spindle head. The experiments are based on measuring the thrust force, evaluating the hole quality in terms of surface roughness and burrs, the formation of chips and post-drilling tool conditions. The results showed that carbide drills with high point angle and smaller diameter generated less thrust force, produced higher quality holes, and formed less built-up edge due to short chips. Besides, tools of the multi-spindle head can be adjusted in any position without affecting the hole quality which is useful for increasing productivity at a higher rate in manufacturing industries. [ABSTRACT FROM AUTHOR]

In this paper, a state-of-the-art review on cutting tool technology in machining of Ni-based superalloys is presented to better understand the current status and to identify future directions of research and development of cutting tool technologies. First, past review articles related to the machining of Ni-based superalloys are summarized. Then machinability of superalloys is introduced, together with the reported methods used in cutting tool design. The current researches on cutting tools in the machining of superalloys are presented in different categories in terms of tool materials, i.e., carbide, ceramics, and Polycrystalline cubic boron nitride (PCBN). Moreover, a set of research issues are identified and highlighted to improve the machining of superalloys. Finally, discussions on the future development are presented, in the areas of new materials/geometries, functional surfaces on the cutting tool, and data-driven comprehensive optimization. [ABSTRACT FROM AUTHOR]

Cutting tool material has a significant effect on the temperature of the tool during machining that determines the tool life and machining performance. The objective of this study is to analyze the effect of reducing the grain size of tool material on tool life and cutting performance in terms of tool temperature and cutting forces during ball end milling of tool steel AISI H13. Tool material was prepared from three different sizes of tungsten carbide (WC) powder mixed with cobalt binder and sintered to fabricate ball end mills. The thermo-mechanical properties of the tool material were determined to investigate the effect of grain size. Machining tests were conducted to evaluate the performance of the tool in terms of tool temperature, cutting forces, and tool wear. Results showing a decrease in tooltip temperature with the reduction in grain size of the tool are the main and novel findings of this paper. The same trend was followed in the case of cutting forces and wear. [ABSTRACT FROM AUTHOR]

A verification experiment was performed to monitor the impact of technical, technological, material, and tool factors on the roughness of the milled surface (average roughness Ra) during plane milling of thermally treated spruce wood. The technological parameters were: four heat treatment temperatures (160 °C, 180 °C, 200 °C, and 220 °C; one sample kept in its natural state), three feed rates (6 m·min-1, 10 m·min-1, and 15 m·min-1), three cutting speeds (20 m·s-1, 40 m·s-1, and 60 m·s-1), three tool rake angles (15°, 20°, and 30°), and three types of used blades (HSS 18% W with AlTiCrN coating, tool steel knife 19 573 induction hardened, and steel knife MAXIMUM SPECIAL 55). The result of the experiments showed the individual effects of the parameters in the following order: used knife, heat treatment, angular geometry, cutting speed, and feed rate. [ABSTRACT FROM AUTHOR]

WC-Co cemented carbides, with low binder content (Co content <4 wt.%), have become prospects as ultra-precision cutting tool materials as a result of their high hardness, which can be ground to a sharp cutting edge when machining tools. In this paper, three cemented carbides, with Co content of 1 wt.%, 2 wt.% and 3 wt.%, were systematically investigated. The mode of preparation, properties, microstructure and ultra-precision turning of these cemented carbides were studied. It has been researched that 0.1 wt.% VC could effectively refine the WC grains to exhibit excellent properties. The optimum sintering temperatures for WC-1Co-VC, WC-2Co-VC and WC-3Co-VC were 1350, 1300 and 1300 °C, respectively. The resultant cemented carbides displayed extremely high hardness (2450, 2377 and 2325 kg/mm2), high relative density (>99%), specific fracture toughness (8.89, 9.01 and 10.17 MPa·m1/2) and transverse rupture strength (1274, 1387 and 1474 MPa). During oxidation, from room temperature to 400 °C, there was a slight reduction in the strength of the cemented carbides with no oxide formed. From 400 to 600 °C, their strength decreased significantly with apparent oxides formed on the surface. At 800 °C, all the cemented carbides experienced a severe drop in strength and massive oxidation on the surface and fracture surface. The cemented carbides were used to make cutting tools used for ultra-precision turning of brass. The surface roughness after machining with the three modified cemented carbide tools, with increasing Co content, were 22, 14 and 17 nm, respectively. [Display omitted] • Low binder WC-Co cemented carbide tool materials were prepared based on spark plasma sintering. • WC-1Co-VC, WC-2Co-VC, and WC-3Co-VC exhibited high hardness of 2450, 2377, and 2325 kg/mm2. • The transverse rupture strength and oxidation of three prepared cemented carbides were studied at high temperatures. • Ultra-precise turning of brass with prepared tools resulted in flat surfaces with surface roughness down to 14 nm. [ABSTRACT FROM AUTHOR]

Objective: The onset of the empirical approach presented in this paper leads to evaluation on the Influence of the Feed Rate, Cutting Speed, and Tool Material on Torque while drilling Prepared Hybrid FRP Laminate using CNC programmed machine. Findings: The influence of cutting condition (feed rate, cutting speed and tool material) on torque were studied and examined. Technique: Design of experiments (DOE) was conducted for the control analysis of the drilling parameters on the response variable (Torque or Twisting Force) by utilizing Taguchi's L27 array the design obtained through Multilevel factorial design in commercial software Minitab 17 to find whether the response variable is minimized by major and/or minor control factors. Result: The percentage deviation of Cutting Speed signifies that torque was least affected rather than other considered factors. The minimum torque was reached in case of cutting speed compared to feed rate and tool material at all levels of factors studied through distinctive main effects plots. [ABSTRACT FROM AUTHOR]

According to performance demands of tool materials for high speed machining difficult to cut materials, gradient cermet composite tool materials were designed and fabricated based on hot pressing sintering after dry pressing. The gradient cermet composite tool materials were composed of surface layer, subsurface layer and substrate and exhibited gradient microstructure and mechanical properties. The surface layer had a high hardness, subsurface layer had a high bonding strength and substrate had a high flexural strength. Three gradient composite cutting inserts were fabricated with the gradient structure on different tool faces. To evaluate the cutting performance of gradient cermet composite cutting inserts, effects of cutting speeds on the tool life and surface roughness were investigated during continuously dry turning 17-4 PH stainless steel. The developed gradient cermet composite cutting inserts showed longer tool life and better machining quality than conventional Ti(C,N) cermet inserts under the same cutting conditions. Cutting speeds played a significant effect on both tool life and failure mode of cutting inserts. The favorable cutting performance of gradient cermet composite cutting inserts was attributed to high surface hardness, good wear resistance of surface layer and reasonable gradient structure. [ABSTRACT FROM AUTHOR]

In the present research, the influence of friction stir welding (FSW) tool material on the mechanical and microstructural properties of friction stir (FS) welded 316L stainless steel butt joints is investigated. FS welds were produced using two different tungsten based FSW tools having identical tool shoulder and pin profiles. In both the cases, the FSW experimental runs were carried out using tool rotational speed of 600 rpm, welding speed of 45 mm/min, axial force of 11 kN and tool tilt angle of 1.5°. The results of the study show that the joints produced using the tungsten lanthanum oxide tool are having superior mechanical and microstructural properties when compared to the joints produced using tungsten heavy alloy tool. Furthermore, the tool degradation study by mass loss and photographic techniques suggests that the tungsten lanthanum oxide tool is more prone to degradation by plastic deformation, whereas the tungsten heavy alloy tool is more prone to degradation by wear. [ABSTRACT FROM AUTHOR]

A non-consumable tool is a vital requirement for friction stir welding (FSW) of high melting point alloys such as steel and titanium. In this investigation, an attempt was made to understand the pre-weld and post-weld microstructural characteristics of three tungsten based alloy FSW tools viz. 90%W, 95%W and 99%W. A naval grade high strength low alloy (HSLA) steel plates of 5 mm thickness were welded using the above tools with a tool rotational speed of 600 rpm and welding speed of 30 mm/min. Microstructural characteristics of the FSW tools, before and after welding, were analyzed using optical microscopy (OM) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). From this investigation, it is found that the tool made of 99% W doped with 1% La 2 O 3 exhibited microstructural stability at elevated temperatures during FSW process. [ABSTRACT FROM AUTHOR]

Abstract: The frictional behavior of a number of conventional tool materials used in the sheet forming industry has been studied by a recently developed tribotester based on flat-die strip drawing. The main objective was to study the frictional performance of the materials and correlate the tribological behavior mainly to the microstructure. Tooling materials tested ranged from powder metallurgical tool steels to nodular cast iron as well as a novel abrasion-resistant cast iron, Carbide steel. A high strength uncoated sheet material commonly used in sheet forming applications was used as a reference sheet material in all tests. The microstructural characterizations of the tool materials were done by SEM image analysis and XRD analysis. Surface roughness characterization was done by 3D optical analysis. A direct correlation between the amount of carbides and the friction coefficient could not be stated based on the specific experimental conditions. [Copyright &y& Elsevier]

Abstract: This work presents a comparative study regarding wear behavior between a novel abrasion resistant cast iron, “Carbide Steel” and a number of conventional tool materials frequently used in the automotive industry. Carbide Steel is basically a high-Cr white cast iron heavily alloyed with cemented carbide. The high chromium content and additional alloying elements like WC, TiC or NbC results in a material containing a large portion of hard, wear-resistant carbides with a composition different from conventional white irons normally used in wear applications. Characteristic properties for the material are: superior as-cast properties, improved wear resistance and hardness. The as-cast hardness of Carbide Steel is comparative to hardened steel but depending on desirable properties of the wear part the alloying content can be varied within a wide range. An interesting aspect of the material is potential for sustainable manufacturing, due to the fact that the critical alloying elements are added in the form of recycled carbide inserts. The experimental work was carried out in a U-bending test equipment to simulate conditions in a stamping process. One type of sheet material was used and seven different conventional tool materials were evaluated. The selection of tool materials ranged from white cast irons to tool-steels and powder steels. The wear patterns were analyzed and expressed in percentages of reduction of weight of the test specimens, galling tendency and temperature variations during the experiments. All parameters were correlated to the number of strokes. The press force was measured and a friction coefficient was calculated. An important conclusion from the experimental work is that Carbide Steel has a significantly higher wear resistance compared to the other conventional tool materials evaluated. Galling is also significantly reduced when using Carbide Steel. The volume part of carbides and the relative size of the same play a significant role in the process leading to less galling and wear, when using Carbide Steel as a tool material. [Copyright &y& Elsevier]

A die wear model based on 'wear work' is put forward for use on die compaction tooling used in powder metallurgy. The model relies on integration of the frictional stress multiplied by velocity with respect to contact area and time. Two specially modified ASTM tribology tests, a pin-on-flat reciprocating test (one test per experimental point) and a continuous loop abrasion test (two tests per experimental point) were utilised to measure the wear on three candidate die materials. Mass loss and dimensional change of test specimens were used to quantify the wear. Based on the test results, a material property dependent constant was calculated for use in the new wear work model. Three different die materials were tested against two types of abrasive hard particles and two types of abrasive tapes. The wear resistance ranking of the three die materials is: WC » 10%V tool steel>CPM T15 tool steel. [ABSTRACT FROM AUTHOR]

Abstract: Owing to improving the mechanical properties of cemented carbides in high speed machining fields, a new composite tool material WC–ZrO2–VC (WZV) is prepared from a mixture of yttria stabilized zirconia (YSZ) and micrometer VC particles by hot-press-sintering in nitrogenous atmosphere. Commercial WC, of which the initial particle sizes are 0.2μm, 0.4μm, 0.6μm and 0.8μm, is mixed with zirconia and VC powder in aqueous medium by following a ball mill process. The sintering behavior is investigated by isostatic pressing under different sintering temperature. The relative density and bending strength are measured by Archimedes methods and three-point bending mode, respectively. Hardness and fracture toughness are performed by Vickers indentation method. Microstructure of the composite is characterized by scanning electron microscopy (SEM). The correlations between initial particles, densification mechanism, sintering temperature, microstructure and mechanical properties are studied. Experimental results show that maximum densification 99.5% is achieved at 1650°C and the initial particle size is 0.8μm. When temperature is 1550°C and particle size is 0.4μm, the optimized bending strength (943MPa) is obtained. The best hardness record is 19.2GPa when sintering temperature is 1650 and particle size is 0.8μm. The indention cracks propagate around the grain boundaries and the WC particles fracture, which is associated with particle and microcrack toughening mechanism. [Copyright &y& Elsevier]

The article presents a study to develop tool concept and selection of suitable tool materials for the thixoforging of steel. It describes the outcome of "THIXOCOMP," a European project relating to material selection, development of tool material and tool concept. It discusses an experiment to develop a tool set-up to produce a damper bracket for a motorcycle by thixoforging.

In recent years, there has been an increasing demand from manufacturing industries for new tool materials such as more wear resistant zinc-alloys, with optimised characteristics regarding short-run sheet-metal parts production. Research on zinc-alloys wear resistance has been performed by a lot of research groups. However, it is very difficult to compare the wear resistance of these materials due to the fact that the investigations have been carried out with conventional methods, such as pin-on-disc or block-on-ring tests. In this paper wear resistance has been evaluated for three different zinc-alloys with different primary phase as die-tool material in forming process equipment. The method used has been the U-bending process, in which the conditions are realistic due to the complex varying load and strain during the forming process. The primary phase in ACuZinc5 is a &epsiv;-phase, which is harder and stronger than the primary phases in Norzak2 and ZA27. ACuZinc5 is almost nine times more abrasive resistant and Norzak2 is 1.8 times more abrasive resistant than ZA27. An other conclusion that can be drawn is the importance of using a methodology during the experimental work that has realistic conditions, both for the tool material and sheet-metal. [Copyright &y& Elsevier]

Tool wear and life of cutting tools are significant evaluation criteria of machining processes. However, the occurring wear mechanisms are influenced by a number of factors such as the process parameters, tool geometry and the material properties of the tool and workpiece. Previous research has shown a high potential for the use of adapted cutting edge microgeometries on cemented carbide cutting tools. The optimal cutting edge rounding is strongly dependent on the tool material properties. However, the influence and relation between the properties of the cemented carbide tool, the microgeometry and the resulting tool wear are not yet completely understood. In this study the tool wear is investigated by systematically varying the mechanical and thermophysical properties of the tool material, the tool microgeometry and cutting process parameters. Significant influencing variables of tool wear are identified and existing relationships quantified. Results show that the occurring wear mechanisms depend on the cutting edge microgeometry as well as the mechanical properties of the cemented carbide. During continuous machining the minimum required cutting edge rounding is a function of the cemented carbide's fracture toughness. This knowledge allows an adaption of the cutting edge microgeometry depending on the substrate properties to reduce the tool wear and achieve a longer tool life. [ABSTRACT FROM AUTHOR]

Chimpanzees are well‐studied, but raw material acquisition for tool use is still poorly understood as sources are difficult to trace. This study pioneers the use of information that can be gleaned from plant scars made by chimpanzees while they source vegetation parts to manufacture termite fishing tools. Source plant species, raw material types and locations relative to targeted termite mounds were recorded for populations at Gombe, Issa, and Mahale in western Tanzania. Recovered bark, twig, and vine tools were traced to 29 plant species, while grass sources were indeterminable. Bark extraction scars remained detectable for months, and thus possibly for as long as the plant is alive, while twig and vine scars preserved for a few weeks only. Scars preserve better than tools, given that twice as many plant species could be linked to the former than to the latter. Some source species were exploited across all sites for the same type of tool material, while two species were sourced for different types. Compared to apes at Gombe and Mahale, Issa chimpanzees carried material from twice as far away, perhaps because the Issa habitat is more open and dry, which entails greater distances between suitable raw material sources and targeted mounds. Site‐specific tools were based on different raw materials, in two cases sourced from the same species, which could suggest learned preferences for particular tool material. "Archaeology of the perishable" as pioneered in this study broadens the methodological approach of the wider field of primate archaeology to include reconstructions of past animal behavior associated with the production of plant based tools. The sourcing of raw material for termite fishing tools by chimpanzees leaves a record on the source plant – scars – that can be studied long after the time of their procurement. Different chimpanzee populations living in western Tanzania used varied tool materials, suggesting preferences for types of tool material used. Apes living in a more open, drier environment, carried raw material for almost double the distance compared to apes living in closer and denser environments. [ABSTRACT FROM AUTHOR]