WC Tool Research Articles

Optimization of CNC milling process parameters with Cryo-Treated WC tools by RSM

In this work, it is proposed how different levels of cryogenic treatment, such as shallow cryogenic treatment (SCT), which occurs at -110°C, medium cryogenic treatment (MCT), which occurs at -150°C, and deep cryogenic treatment (DCT), which occurs at -175°C, affect the machinability of P20 material. In this paper, an effort is made to optimize the process variables in machining P20 steel with cryogenically treated tungsten carbide (WC) cutting tools in the CNC milling process using the Response surface methodology (RSM) and Taguchi method. Data for this study is gathered using the Box-Behnken design of response surface methodology (RSM). Cutting speed (CS), feed rate (FR), depth of cut (DOC), and the lowering temperatures are considered significant process parameters that are functions of performance measures. The observations revealed that there is a substantial correlation between performance measures and cryogenic treatment, cutting speed, feed, and depth of cut. The purpose of this work is to model the output parameters and optimize the process parameters using RSM.

Performance comparison of EDM oil and biodiesel flushing media while µED milling of Inconel 718

ABSTRACT Hydrocarbon-based flushing media have proved their superiority as a flushing media for EDM process in terms of performance characteristics, but serious health issues such as skin cancer, respiratory problems, and lung cancer are predominant among the operators. An experimental investigation was conducted to study the feasibility of the biodiesels as a flushing media during µED Milling of Inconel 718 alloy with WC tool under three different discharge energy range. The behavior of biodiesel is the same as EDM oil, but the EDM oil have a higher metal removal rate and minimum roughness compared to biodiesel. Palm biodiesel was in close proximity range with EDM oil than jatropha and karanja biodiesels in terms of response measures. The breakdown voltage of biodiesels was found to be higher than EDM oil. Crater diameter increased by 16%, 22%, and 31%, respectively, with palm, jatropha, and karanja biodiesel fluids than EDM oil. Biodiesel could be a real alternative to hydrocarbon oil for µED milling in terms of performance and safer environment. Minimum hardness was achieved when the biodiesels were used as the flushing media at considered discharge energy range due to lesser carbon deposition. MRR was decreased by 55% with palm biodiesels as compared to EDM oil dielectric fluid. Microhardness was increased by 10% with EDM oil as compared to Karanja biodiesel under considered discharge energy.

Fatigue strength improvement due to alloying steel weld toes with WC tool constituent elements through friction stir processing

Friction stir processing (FSP) enables surface modifications can likely be applied as a new post-weld treatment for improving fatigue strength. When applying FSP to high-strength materials, tool wear occurring at the interface between the tool tip and the topmost steel layer has been regarded as an unavoidable issue and is related to the tool rotational speed. The present study investigated the relationship between the tool rotational speed and fatigue strength of arc-welded high-strength low-alloy (HSLA) steel joints with weld toes subjected to FSP using a spherical-tip WC tool. FSP was conducted on the weld toe of HSLA steel joints with various tool rotational speeds. Tool wear increased with increase in tool rotational speed, and consequently contents of constituent elements of the WC tool increased in the topmost steel layer of weld toes, leading to large increase in fatigue strength. One reason for the increase with tool rotational speed is significant increase in solid solution hardening due to supersaturated W and C in the topmost steel layer consisting of martensite laths. The hardened topmost steel layer prevented fatigue crack initiation, and the increased fatigue strength depended on the contents of supersaturated W and C. Alloying of the topmost steel layer with tool constituent elements of W and C accompanied with WC tool wear during FSP is unique additive manufacturing to increase the fatigue strength of welded joints, and can be employed locally on structural components susceptible to fatigue.

Analysis of suitability of WC tool for joining Inconel 601 alloy by electric assisted friction stir welding

The paper focus on the study and analysis of tool wear of Tungsten carbide tool for joining high strength material by Electrically Assisted Friction Stir Welding. The tool material selected for the experiment is Tungsten Carbide and base material is Inconel 601 plates. Certain parameters have been considered for the experiment such as tool speed, welding speed and current supplied. An additional electric current of about 4 V DC is supplied considering the EAFSW process. The feed rate for the experiment is about 10, 20 and 30 mm/min. The paper focuses to study the use of electric current for hybridization of FSW process and utilize the hybrid process to join high strength material by WC tool. A comparative study has been done to analyse the mechanical property of Inconel 601 joined by FSW and EAFSW and the tool wear in both the cases has also been studied. An improvement in UTS by 21.62 percent has been observed in EAFSW process than FSW process.

Correlation analysis of Machining parameters against cutting forces during Machining of 17–4 PHSS using cryogenic treated and untreated WC insert

17–4 PH stainless steel is of martensite structure well known for its combination of corrosion resistance in multiple environments while retaining high strength properties, including hardness. There exists a lack of study in optimization of machining parameters to control its cycle time and tool wear of the WC cutting tool used in machining difficult-to-cut material for improved mass production capabilities. The correlation analysis allowed it to be determined that the speed and cutting force have a negative interconnection whereas the feed and depth of cut have a positive interconnection with the cutting force for both cryogenic treated and conventional WC tool in varying degrees. Thus, setting the stage for predictive maintenance algorithms and possible improvement in throughput time.

Performance evaluation of tool coatings and nanofluid MQL on the micro-machinability of Ti-6Al-4V

Micromilling of difficult-to-machine materials like Ti-6Al-4V alloy suffers from drawbacks such as tool wear and catastrophic tool breakage due to the tiny diameter of the micro tool. Hence, in this paper, an effort has been made to prolong tool life and improve surface quality via hybridization of water and CuO nanofluid-based MQL with PVD coated (AlTiN/TiAlN) and uncoated WC micro end-mill in micromilling of Ti-6Al-4V alloy. The results exhibited minimum surface roughness at lower concentration (0.25 vol%) of CuO nanofluids with AlTiN coated WC tool and diminished tool wear and built-up edge formation at higher concentration (1 vol%) water-based CuO nanofluids. Under various environmental conditions, the average size of the top burr width was determined on both the up and down milling sides. The minimum average burr width of 9.93 μm was obtained in up milling using 0.25 vol% CuO nanofluids condition with AlTiN coated tool. In the case of down milling, the minimum burr width was 10.58 μm when using 0.25 vol% CuO nanofluids with TiAlN coated tool. Furthermore, significant improvements in tool life and surface quality have been observed through the hybridized sustainable environments obtained by the combined utilization of MQL and coated tools.

Optimizing the Machining performance of CNC tools inserts coated with Diamond like Carbon Coatings under the dry cutting environment

In this research work we have coated WC (tungsten carbide) tool inserts with diamond like carbon coatings. The deposition was done using the thermal Chemical Vapour Deposition (CVD) method. We have used bagasse of sugarcane which is an agriculture waste as a carbon precursor for developing the diamond like carbon coatings. Surface finish, cutting temperature and cutting forces of as-developed diamond like carbon coatings on the WC inserts were examined and analyzed in this research work. For confirming the presence of diamond like carbon coatings on the surface of coated tungsten carbide (WC) tool inserts substrate we have used Raman spectroscopy, X-ray diffraction (XRD) and Field Emission Scanning Electron Microscope (Fe-SEM). The increase in the hardness on the developed coated samples were inspected by performing the hardness test on the coated substrates. The average evaluated Vickers Hardness number were found to be 1455.24 HV and 950.65 HV for both coated as well as un-coated samples respectively. This shows 53% rise in the hardness of the un-coated WC inserts.

CVD Diamond Coated Tungsten Carbide (WC) Tool Inserts

In this paper a self-developed polycrystalline diamond coating was done on tungsten carbide (WC) tool insets by using simple thermal chemical vapor deposition technique. The growth of these diamond films has been carried out at ~900 ºC temperature. The as-grown polycrystalline diamond films on the surface of tungsten carbide tool inserts have been characterized using Raman spectrometer and scanning electron microscope (SEM). The morphological studies reveal that the as-grown diamond films are of high crystalline quality. The as-grown diamond films possess compressive stress. The micro-hardness indentation test of the as-grown diamond films on WC tool inserts and bare have also been done and it has been found that the Vicker’s hardness of the as-grown diamond WC tool inserts is found to be 1423.32 HV which is 29% better than the un-coated tools.

Alloying a topmost steel-plate layer with WC-tool constituent elements during friction stir processing

Friction stir processing (FSP) on weld toes of arc-welded high-strength steel joints was found to significantly increase the fatigue strength. This can be explained by an accompanied increase in the radius of curvature at the weld toes and grain refining, solid solution hardening in the topmost layer. Solid solution hardening seemed to be accompanied with the WC tool wear during FSP. The topmost layer contained the supersaturated W and C, leading to martensitic transformation. To clarify the alloying mechanism in the topmost layer, the stop action technique was employed during FSP, immediately followed by water-cooling the tool and the steel plate. The interface between the WC tool and the topmost steel-plate layer in the obtained keyhole samples was investigated. As tool rotational speed increased, Fe atoms diffused from the steel plate into the WC-tool Ni-based binder regions. Subsequently, some of the WC particles in the tool reacted with the Fe atoms to form Fe4W2C. The Fe4W2C particles agglomerated at the interface, followed by formation of a thin layer. The intermediate layer was fragmented and decomposed by FSP shear stress and friction heat, and alloying the topmost steel-plate layer with the WC-tool constituent elements.

Theoretical and experimental investigation into the machining performance in axial ultrasonic vibration-assisted cutting of Ti6Al4V

Axial ultrasonic vibration-assisted cutting (AUVC) has been proved to have better machining performance compared with conventional cutting methods; however, the effect of numerous and complex influencing factors on machining performance has not been clearly revealed, and a recommended combination of cutting conditions has not been proposed yet, especially for difficult-to-machine material such as Ti6Al4V alloy. This paper focuses on the experimental and theoretical investigation into Ti6Al4V machining performance with AUVC method. First, a retrospective of the separation characteristics of AUVC is provided, and the variable parameter cutting characteristics are demonstrated. The influencing factors on machining performance are classified into four categories: machining parameters, vibration parameters, tool choice, and cooling conditions. The relationship between these factors in terms of their effect on machining performance is established theoretically. Then, it describes experiments to determine the influence of these factors on cutting force, tool life, and surface roughness. For absolute influence, the orders for cutting force, tool life, and surface roughness are respectively cutting depth > amplitude > feed rate > rotation speed, rotation speed > feed rate > amplitude > cutting depth, and feed rate > amplitude > cutting depth > rotation speed. However, for relative influence, the order is unified as amplitude > feed rate > rotation speed > cutting depth. Finally, it suggests a smaller feed rate, larger amplitude, moderate rotation speed, and smaller cutting depth in addition to a WC tool coated with TiAlN and used under HPC cooling condition for optimal performance of AUVC. This recommendation is based on the theoretical analysis and experimental results of cutting force, surface roughness, and tool life.

Microstructure and mechanical properties of friction-stir welded interstitial-free steel using WC tool

In the present work, interstitial-free steel plates were joined using friction-stir welding. The weld integrity was found to be in excellent condition. This work emphasises the evolution of microstructure and the enhancement of mechanical properties by friction-stir welding. The microstructural characterisation using optical image microscopy revealed the refinement of grains in the nugget zone. Vicker’s hardness test stopped to a maximum of ~91 VHN in the nugget zone compared to ~40 VHN in the base material. The tensile test of the welded sample concluded that the samples fractured in the region away from the nugget zone and towards the base material. The results are conclusive that friction-stir welding is an excellent approach for joining interstitial-free steel components for automotive applications.

Cumulative reduction of friction and size effects in micro milling through proper selection of coating thickness of TiAlN coated tool: Experimental and analytical assessments

It has been shown earlier that abrasion-resistant coatings on cutting tool can reduce tool wear and friction in micro milling and other machining processes. However, due to coating, the edge radius of micro end mill increases, and the influences of size effects become significant. Therefore, proper selection of the coating thickness is crucial to reduce friction and size effects together. In this article, thin-film coating of TiAlN of different thicknesses (0.5, 1, 2 and 3 μm) has been applied on the WC micro end mill using the physical vapour deposition (PVD) method. First, the enhanced tribological performance of TiAlN coating over un-coated WC material has been verified by evaluating the hardness and coefficient of friction values of both the materials. Next, the appropriate coating thickness value has been selected by experimental and analytical assessments of the machinability parameters and stability limit, respectively, in micro milling of P-20 steel. From the cumulative experimental and analytical investigations, TiAlN coated tool having coating thickness ≈ 1 μm has been found to be the appropriate thin film thickness by witnessing improved machinability and stability limit as compared to the uncoated WC tool and TiAlN coated tools of other coating thicknesses.

Characterisation of worn WC tool using STEM-EDS aided by principal component analysis.

Interdiffusion and chemical reactions contribute to tool wear in metal machining. Increased understanding of these processes, through characterisation of worn tools, can facilitate design of more resilient materials through chemical and diffusional passivation. However, the unknown reaction conditions, the large number of elements, and the formation of interspersed phases makes for a complex analysis. Here, we demonstrate the use of scanning transmission electron microscopy and energy dispersive X-ray spectroscopy for characterising the interaction layer between a titanium alloy and a cemented carbide tool. Principal component analysis is used to find chemical correlations and help separate signals from embedded phases. Crucially, we evaluate the required X-ray count statistics from simulated spectrum images and theory prior to the experiment. We find no indications of intermediate phases between the original WC and the metallic W interaction layer. Furthermore, we find enrichment of minor constituents in the titanium alloy closest to the tool which alter the solubility of out-diffusing species, suggesting strong interrelations between the diffusion processes.

Evaluation of tensile and microstructure properties of AA2014 and AA7075 FSW weldments developed by HSS-10%Co and WC tools

Difficult to weld series of high strength Al grades by fusion welding were known to join by Friction stir welding (FSW) process. Joints of high strength AA 2021 and AA7075 base materials obtained by FSW technique were discussed in the present work. Tool materials with different surface hardness, High Speed Steel and Tungsten Carbide, were developed to commence welding. FSW Process parameters were taken as 1120, 1400 and 1800 rpm with feeds rates of 30, 40 and 50 mm/min. Base material and tool material combinations were chosen to produce weldments. Weld joints were evaluated using tensile test. Microstructure analysis was presented from the results of images obtained by Metallurgical Microscope. Weldments joined by HSS tool have shown better tensile properties compared to weldments obtained by tungsten carbine tool. Tunnels effects were seen in the weldments made from WC tool.

Influence of hole quality on fatigue life of drilled CFRP with the different ply orientation angle

In this study, the effect of drilling quality on fatigue life of UD, 0/90, and ± 45 fiber angle carbon fiber reinforced plastics (CFRP) was investigated. CFRPs were drilled using WC, HSS, and Brad Spur tool types that have different geometries and materials at different feed rates of 0.05, 0.10, and 0.15 mm/rev, and at the different spindle speeds of 1000, 3000 and 5000 rev/min. Thrust forces were measured during the drilling of CFRPs, and surface roughnesses, deformation factors, and maximum tensile forces were measured after drilling operations. Thrust force, surface roughness, and deformation factor were evaluated in terms of drilling quality. The drilling parameters that cause the best, average, and worst drilling quality were determined. Then, fatigue behaviors of CFRPs drilled in these drilling parameters were investigated. Fatigue tests were carried out at %75, %80, %85, and %90 load ratios based on the lowest tensile force of the drilled samples. As a result of the study, it was determined that the thrust force, the deformation factor, and the surface roughness increased as the feed rate increased. However, the thrust force, the deformation factor, and the surface roughness decreased as the spindle speed increased. Besides, the best drilling quality was obtained from the drilling operation performed using WC tool type, at a spindle speed of 5000 rev/min and a feed rate of 0.05 mm/rev. The worst drilling quality was obtained from the drilling operation performed using Brad Spur tool type, at a spindle speed of 1000 rev/min and a feed rate of 0.15 mm/rev. With the decreasing drilling quality, a significant decrease occurred in the tensile force and fatigue life of CFRPs. The tensile load and fatigue life of CFRPs drilled in optimum drilling parameters were obtained higher. In the case of selecting the correct drilling parameters, it was observed that the reduction in fatigue life of CFRPs could be prevented ratios of %22–49.

A Comparative Performance Analysis of Uncoated and Coated WC Drills during Forging Brass Drilling Operation

In this study, the performances of the WC tools coated with TiCN and AlCrN by filter cathodic arc in hole drilling of forging brass were investigated and compared with that of uncoated one. The performances were evaluated using the exit burr height (EBH) criterion and process capability indices as a function of number of parts drilled with the three types of drills. The results showed that there were significant differences of EBH and the process capability index of Cpm during drilling of the workpieces with the three types of drills. The desired EBH values of 0.152-0.1535 mm, roughness values of 2-3 µm and drilled diameters of 17.79-17.8 mm were achieved with the appropriate operating conditions including cutting speeds and feed rates ranging from 0.17 to 0.19 mm/rev and 55 to 57 m/min, respectively.

Characterization of tool wear in similar and dissimilar joints of MS and SS using EAFSW

Abstract Friction Stir Welding (FSW) faces many issues while joining high strength material. In this study an external secondary heat source from a DC source kept at 4 V supply has been used to in between the tool and the workpiece to give an external heat source to FSW and use the method as Electrically Assisted Friction Stir Welding (EAFSW) process. This study represents analysis of mechanical properties of Mild steel (MS) and Stainless-Steel (SS) joint, made by both FSW and EAFSW. An effect of the secondary heat source of electric energy on the mechanical property of the joint and to the tool wear while joining similar and dissimilar material of MS and SS has also been studied. The study represented the effect of the addition of a secondary heat source of an electric current heating to FSW and the impact of various process parameters like tool rpm and feed on the tool wear. The results have been shown to express an expected tool life of WC tool material for joining mild steel and stainless steel. Th experimentation has proved the suitability of Tungsten Carbide as tool material for joining high strength material such as MS and SS. It has also been observed that with suitable utilization of process parameters and secondary heat sources, the heat at the nugget zone increases causing better mixing of the nugget zone. Due to a generation of higher heat at the nugget zone, less tangential and radial load occurs at the tool pin resulting less tool wear and better tool life.

Wear behavior of Ni-B coated-hard anodized Al7Si alloy and machining performance with ZrN ceramic film coated carbide tool

In this study, it is aimed to increase the wear resistance of Al7Si alloy, which is widely used in the manufacturing industry, with different surface treatments and to propose an effective and economical cutting tool coating for machining process of the alloy. Accordingly, precipitation hardening heat treatment, Hard Anodizing and Ni-B coating processes were applied to cast Al7Si alloy samples. The structural, mechanical and tribological properties of the samples were characterized after the surface treatments. Also, the machining performance of Al7Si alloy with uncoated and ZrN ceramic film coated carbide end mills was investigated. The milling processes were performed to determine the actual working performance of the tools. SolidCAM i-machining module, which has become widespread recently, was used as intelligent machining instead of the tool paths used in traditional methods. After the precipitation hardening heat treatment, Hard Anodizing and Ni-B coating process were applied to the alloy, the wear volumes were greatly reduced. The lowest wear volume was obtained for the Ni-B coated Al7Si alloy, which also achieved the lowest coefficient of friction. After machining studies, it was determined that the ZrN coating reduced the wear on the WC tool approximately 4 times and increased the workpiece surface quality compared to the uncoated tool.

A study on the machinability of advanced arc PVD AlCrN-coated tungsten carbide tools in drilling of CFRP/titanium alloy stacks

This study aims to investigate the effect of an aluminum chromium nitride (AlCrN) coating on tool wear and hole quality in the conventional drilling process of carbon fiber-reinforced plastic (CFRP) composites, titanium alloy (Ti), and CFRP–Ti stack workpieces popular in the aerospace industry. The advanced arc plasma acceleration (APA) method of physical vapor deposition (PVD) was used for all AlCrN coatings. The drilling experiments were conducted with uncoated drills as well as AlCrN-coated drills. When drilling CFRP only, the AlCrN coating was removed at the drill cutting edges and the margin area, which suggests the carbon fibers abraded the coatings. When drilling Ti only, the AlCrN-coated drill mitigated the Ti adhesion formation, which resulted in less tool wear. In addition, hole quality for both CFRP and Ti was improved when the coating was used versus the uncoated tool. The machinability of CFRP–Ti stacks in the drilling process was improved by utilizing the advanced AlCrN coating on the WC tool in terms of drilling forces and hole quality parameters such as average hole size, average hole roundness, hole surface roughness, and Ti exit burr height.

Studies on wear behavior of AlTiN-coated WC tool and machined surface quality in micro endmilling of Inconel 718

The recent developments in science and technology lead to the miniaturization of components in fields like aerospace, biomedical, and electronics. Due to the small tool dimensions and premature tool failure, the tool wear behavior is complicated in micro endmilling of difficult-to-cut materials. In this work, the influence of size effect on wear behavior of AlTiN-coated WC micro endmill and its effects on surface roughness, burr formation, and chip formation during machining on Inconel 718 was studied. It was found that adhesion, delamination, chipping, cutting edge rounding, and flank wear are the significant wear behaviors on AlTiN-coated WC micro endmill during machining of Inconel 718. Workpiece adhesion was observed to be severe in the plowing dominant region. The tool life with 6-μm feed/tooth was found to be 60% more than that with 0.5-μm feed/tooth. The tool failure criteria based on the width of flank wear and cutter edge radius were observed close to 27 and 9 μm, respectively. The feed/tooth adjacent to cutting edge radius was observed as the most favorable cutting condition for good tool life and surface quality.