High-speed Steel Drill Research Articles

Multi-Criteria ranking algorithm for high quality of products in high performance drilling Operation: A case study for considering the Wide-Web and Cryo treated drills

Among the most commonly used tools in the industrial business, high-speed steel (HSS) tools rank first. A large web thickness and cryogenic treatment were used to obtain the most significant improvements in machining quality with the HSS tool. The results of this study are presented in this publication. Being stiffer in nature than normal drills, they have always had the ability to drill straighter, deeper, and more exact hole diameters than standard drills. Furthermore, wide-web drills often allow for feed rates that are approximately 20% faster than standard drills, and the strength of a wide belt makes it the ideal tool for deep cuts in hard materials. On the basis of a multi-criteria classification technique, this study discusses how to select the appropriate process parameter to obtain the highest possible level of drilling quality. These findings concern the optimization of drilling settings utilising a strategy to get the lowest possible deviation from cylindricity, surface roughness (Ra), roundness error, and burr. Cylindricity, surface roughness (Ra), roundness error, and burr are all considered in this study. Mistreating the L9 orthogonal die on the CNC milling machine resulted in a series of drilling trials, which were then recorded. The traces were made on the ZE41 block, which was produced by gravity die casting, with a cutting tool of a 4 mm diameter treated HSS drill, which was employed during experimental work in dry cutting circumstances to make the traces. The Combinative Distance-based ASsessment (CODAS) and ANOVA were used to determine the main spindle speed, feed rate, web thickness, Pont Angle, and Cryogenic Treated Drill Tools that had an impact on the response were determined. It is investigated whether information factors have a main or cooperative effect on normal reactions.

Thermal Investigation on Coated and Uncoated HSS Twist Drill using ANSYS Software

Abstract: In drilling, a cylindrical hole is produced in workpiece, removing the material inside the workpiece. The cutting tool used in drilling operation is called ‘Twist Drill’; it rotates and allows the material to be removed from the workpiece in the form of chips and thus drill the hole. Cutting fluids or coolants are used to perform this operation smoothly. The coating on the drill bits helps to reduce friction in the cut and the heat buildup in the drill bit. Coating also helps in protecting against corrosion. The present work focuses on the features of uncoated High Speed Steel (HSS) Twist Drill bit and Titanium Nitride (TiN) and Titanium Aluminium Nitride (TiAlN) coated on HSS Drills. The workpiece material was Mild Steel and the drilling operation was done using normal machining condition i.e. in presence of coolant. The cutting parameters used are cutting speed (35.5 m / min), spindle speed (1500 rpm), feed rate (0.2 mm / rev.), depth of cut (10 mm). These parameters were kept constant. Temperatures were measured with the help of thermal imaging camera and with the help of ANSYS software thermal analysis were done. Experimental results showed that the average rise in temperature of uncoated HSS tool was higher as compared to TiN coated and TiAlN coated HSS tools. TiAlN coated drills showed the least average rise in temperature. Keywords: High Speed Steel (HSS) Drill, TiN and TiAlN Coated HSS Twist Drill, Mild Steel (MS), Thermal Analysis, ANSYS Software.

Influence of Cutting Parameters on the Service Life of Twist HSS Drill Bit When Drilling C35 Steel

This work aims to understand the influence of cutting parameters on the twist high-speed steel (HSS) drill bits wear when drilling C35 steel before and after quenching. An experimental investigation has been conducted using the planning experience methodology (L8) on C35 steel in the annealed and hardened states. The input parameters are cutting regime elements, cutting speed (Vc), feed rate (f), and drill diameter (D), while the output parameters are the tool wear related to its tool life. The most interesting phenomenon is the controversial effect of cutting speed when drilling C35 steel in hardened conditions. The drilling life increases with increasing cutting speed for different cutting regimes (1 to 8). In addition, the 20 mm diameter drill related to the high value of the depth of cut (f) has given better life before and after hardening, contrary to the literature on cutting tool life. The analysis of variance (ANOVA) has showed that the feed rate (f) is the most significant factor in the annealed state while it is the depth of cut (ap) in the hardened state. The correlation coefficients R2 determined by the ANOVA before, and after quenching, are very satisfactory, and testify the good adequacy of the proposed model.

Аналіз прогресивних інструментів для оброблювання отворів на верстатах з ЧПК

При оброблюванні заготовок на верстатах з ЧПК нерідко виникає необхідність свердління отворів, вісь яких проходить під кутом до оброблюваної поверхні, або отвір знаходиться на конусній чи криволінійній поверхні. В цих випадках виникають труднощі направлення свердла без попереднього центрування. Також важливо виконувати попереднє центрування для свердл із швидкорізальної сталі з великою довжиною робочої частини, які можуть відхилятися від осі під дією осьової сили, оскільки контакт вершини свердла відбувається по лінії поперечної різальної кромки.
 When machining workpieces on CNC machines, it is often necessary to drill holes, the axis of which passes at an angle to the work surface, or the hole is on a conical or curved surface. In these cases, it is difficult to direct the drill without pre-centering. It is also important to perform pre-centering for high-speed steel drills with a large working part length, which can deviate from the axis under the action of axial force, because the contact of the drill bit is along the line of the transverse cutting edge.

Analysis of Hole Quality and Chips Formation in the Dry Drilling Process of Al7075-T6

Millions of holes are produced in many industries where efficient drilling is considered the key factor in their success. High-quality holes are possible with the proper selection of drilling process parameters, appropriate tools, and machine setup. This paper deals with the effects of drilling parameters such as spindle speed and feed rate on the chips analysis and the hole quality like surface roughness, hole size, circularity, and burr formation. Al7075-T6 alloy, commonly used in the aerospace industry, was used for the drilling process, and the dry drilling experiments were performed using high-speed steel drill bits. Results have shown that surface roughness decreased with the increase in spindle speed and increased with the increase in the feed rate. The hole size increased with the high spindle speed, whereas the impact of spindle speed on circularity error was found insignificant. Furthermore, short and segmented chips were achieved at a high feed rate and low spindle speed. The percentage contribution of each input parameter on the output drilling parameters was evaluated using analysis of variance (ANOVA).

Study on roughness and form errors linked with tool wear in the drilling process of an Al-Si alloy under high cutting speed using coated diamond-like carbon high-speed steel drill bits

• High cutting speed can reduce cycle time, but it can increase cutting tool wear. • High-speed steel is used in machining processes, having cutting speed limitations. • Aluminum alloys are used in mechanical parts it requires high cutting parameters. • DLC application is an alternative to reduce cutting tool wear at high cutting speed. • Process parameters are essential to ensure product quality, roughness and form errors. Materials engineering development has led to steel and cast iron replacement by Aluminum-Silicon – Al-Si alloys in various applications due to the adequate good strength-to-weight ratio and corrosion resistance. These features of Al-Si are extremely relevant for the performance improvement of many products by applying this alloy instead of the usual materials. However, studies have shown that the machinability of these materials presents multiple negative aspects, such as adhesion and abrasion. Therefore, optime cutting parameters and tools need to be selected to combine tool life with product quality. Using hard coatings with high chemical inertia, such as Diamond-Like Carbon (DLC), has shown promising results when machining aluminum alloys. Generally, in drilling, roughness, deviations in diameter, circularity and cylindricity represent the quality of a hole. Cutting speed directly influences tool wear and hole quality. Thus, this study aimed to evaluate the quality of holes machined using high-speed steel tools in an Al-Si alloy on the influence of cutting speed and the use of DLC coating. Tools with brazed Polycrystalline Diamond (PCD) are usually chosen for machining aluminum alloys, which can absorb high cutting speeds. In this paper, the replacement of brazed PCD is studied for high-speed steel coated with a thin film that can guarantee the same performance. The tests were carried out varying the cutting speed (V) in 340, 360, and 430 m/min, comparing DLC coated with uncoated tools. Flank wear was analyzed after each machining run using Scanning Electron Microscopy (SEM). The results showed that cutting speed directly influences the roughness, diameter variation, and flank wear. DLC coating did not show hole quality improvements as it presented adhesion problems on the high-speed steel substrate.

Peculiarities Regarding the Smooth Entrance of the Drill in Cutting When Processing Steel

Metal drilling is one of the most common methods of obtaining cylindrical bores. At the same time, the drill is the cutting tool that cuts in the most difficult conditions and consequently any measure that leads to the improvement of the cutting process is useful. The smooth entrance in the cutting is a way to increase the durability of the drill and consequently specific devices have been developed. One of these devices is shown in this paper and previous research shows the effectiveness of its use in drilling. The analysis of the device shows that it is used for cutting 41MoC11 and C45 steels with high speed steel drills, which are in a small range of sizes. The active element of the device is identified, a helical spring working for compression, and by calculating the respective axial force of the torque, is determined exactly the range of diameters of the drills that can cut effectively. At the same time is analyzed the way of enlarging the range of drills used with the device for smooth entrance in cutting, by introducing a second spring, concentric with the first, and which works simultaneously with it, thus the device was reengineered.

Feasibility of tool configuration and the effect of tool material, and tool geometry in multi-hole simultaneous drilling of Al2024

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.

Characterization of machinability of sintered steel foams having different porosities during drilling operations

Steel foams are a new class of engineering materials with exceptional structure and properties. Foams produced by powder metallurgy generally have a near-net shape, however, sometimes machining operations may be required. The presence of porosity in steel foams significantly affects the cutting process and causes poor machinability. This study deals with the evaluation of the machinability of Cu-Ni-Mo-based steel foams having different porosity produced by powder metallurgy. High speed steel and carbide-tipped drills were used for the drilling. All tests were performed in dry condition with drill diameter of 3 mm. The drilling characteristics were evaluated in terms of the surface roughness, chip formation, drilling force, tool wear, microstructure and hardness change after drilling. The machinability was also evaluated by measuring average width of breakout and skewness values of the hole drilled. The results indicated that the increase of porosity negatively affected the drilling quality of high porous steels. Both drills broke the chips in powder form and produced discontinuous chips. High porous parts exhibited higher hardness change as compared to lower ones. The carbide drill showed acceptable drilling forces and surface quality. HSS drill is not suitable for drilling due to poor hole quality and high drill wear. Highlights Steel foams exhibit poor machinability due to highly porous structure. Porosity and tool type significantly affect the surface integrity of steel foams. Surface roughness and drill wear increased with increasing porosity; however, feed force decreased. Intense presence of pores decreases the tool life remarkably. The skewness values of hole are positive in all porosities. Carbide-tipped drill produced the finest hole quality. The larger damage was observed at the exit of the drilled holes with HSS drill.

An experimental investigation of thrust force, delamination and surface roughness in drilling of jute/carbon hybrid composites

Purpose This paper aims to deal with the influence of cutting parameters on drill thrust force, delamination and surface roughness in the drilling of laminated jute/carbon hybrid composites. Design/methodology/approach The hybrid composites were fabricated with four layers of fabrics, which are arranged in different sequences using the hand-layup technique. Drilling experiments involved drilling of 6 mm diameter holes on the prepared composite plates using high-speed steel and solid carbide drill materials. Analysis of variance was used to find the influence, percentage contribution and significance of drilling parameters on drilling-induced damages. Scanning electron microscopy analysis was also conducted to understand the fracture behavior and surface morphology of the drilled holes. Findings The experimental study reveals that the most significant effect was the feed rate influenced the drill thrust force and the drill speed influenced both delamination factor and surface roughness of hybrid fiber-reinforced composites. From observations, the suggested combination for drilling jute/carbon hybrid composites is carbide drill, spindle speed of 1,750 rpm and feed of 0.03 mm/rev. Originality/value The new lightweight and low-cost hybrid composites were developed by hybridizing jute with carbon fabrics in the epoxy matrix with interplay arrangements. The influence of cutting speed and feed rate on delamination damage and surface roughness in the drilling of hybrid composites have been experimentally evaluated.

The Investigation of Hole Delamination in Drilling Kevlar Composite Panel Using HSS Drill Tool

The drilling process has been mostly used in composite panel machining to be a final product. It becomes a critical process when the composite product requires a high hole precision for the purpose of assembly and quality standard. Machining Kevlar composite is a difficult task due its hardness, fiber layer bounding and fiber orientation. The cutting condition needs to be controlled carefully to minimize the vibration, cutting temperature and hole delamination. This paper discusses the investigation of hole delamination in drilling Kevlar composite panel. The twist drill type of High-Speed Steel (HSS) drilling tool with 12 mm diameter was used to drill a 4 mm thick Kevlar composite panel. Three levels of spindle speed (1000 rpm, 1400 rpm and 2000 rpm) and three levels of feed rate (130 mm/min, 160 mm/min and 180 mm/min) were selected as the configuration of cutting condition. The hole diameter was measured and was compared to the drill tool diameter. The result of the experiment shows that the cutting condition gave significant effect to the drill hole delamination factor. The highest delamination factor was 1.36 and achieved by drilling condition with spindle speed of 1000 rpm and feed rate of 160 mm/min. The lowest delamination factor was 1.161 and achieved by drilling condition with spindle speed of 2000 rpm and feed rate of 130 mm/min.

Оценка возможностей улучшения обрабатываемости изделий инструментом из быстрорежущей стали с модифицированной рабочей частью

There are presented results of the comparative operation of two high-speed steel drill types: common ones and those with the working part modified by low-temperature plasma effect. A possibility to improve product machinability according to the criterion of productivity at the expense of the durability period increase of modified drills is shown. 
 There are formulated requirements to the results of low-temperature plasma modification ensuring tool life increase.

Optimization of process parameters on drilling of natural fibres reinforced in epoxy resin matrices using Taguchi–Grey relational analysis

PurposeThe purpose of this paper is to identify the ideal process parameters to be set for the drilling of hybrid fibre-reinforced polymer (FRP) (kenaf and banana) composite using High-Speed Steel drill bits (5, 10, 15 mm) coated with tungsten carbide by means of statistical reproduction of the delamination factor and machining force using Taguchi–Grey Relational Analysis.Design/methodology/approachThe contemplated process parameters are Feed, Speed and Drill Diameter. The trials were carried out by taking advantage of the L-27 factorial design by Taguchi. Three factors, the three level Taguchi Orthogonal Array design in Grey Relational Analysis was used to carry out the trial study. Video Measuring System was used to identify the damage around the drill region. “Minitab 18” was used to examine the data collected by taking advantage of the various statistical and graphical tools available. Examination of variance is used to legitimize the model in identifying the most notable parameter.FindingsThe optimised set of input parameters were found out successfully which are as follows: Feed Rate: 450 mm/min, Cutting Speed: 3,000 rpm and Drill Diameter of 5 mm. When these values are fed in as input the optimised output is being obtained. From ANOVA analysis, it is apparent that the Speed (contribution of 92.6%) is the most influencing parameter on the delamination factor and machining force of the FRP material.Originality/valueOptimization of process parameters on drilling of natural fibres reinforced in epoxy resin matrices using Taguchi–Grey Relational Analysis has not been previously explored.

Evaluation of the effect of cryogenic treatment of HSS drills at different holding time in drilling AISI 316-SS

Cryogenic treatment has been acknowledged as an effective means of extending tool life of many cutting tool materials, thus improving productivity significantly. However, the real mechanisms which guarantee better tool performance have not been very clearly understood. This work aims to study the effect the effect of different holding time during cryogenic treatment on M2 high speed steel (HSS) drills. The performance of these cryo-treated tools were compared on the basis of thrust force, surface roughness, tool wear and chip formation by drilling on AISI 316 SS. The thrust force was least at 600 rpm and the rapid deep cryogenic treated (DCT) drills had much less thrust force (45%–55% lower) compared to untreated drills. From the various parameters involved it was observed that the cryo-treated tool bit at holding time of 24 h and at a cutting speed of 600 rpm and feed rate of 0.06 mm rev−1 showed better performance. The relative wear resistance of the cryo-treated drill at 24 h was at least two times better than the untreated drill while the surface roughness of the holes drilled with this drill was half that of those drilled with untreated drills. This investigation was further extended by gradual shallow cryogenic treatment (GSCT) and gradual deep cryogenic treatment (GDCT) of drills at the optimum holding time of 24 h. Both GSCT and GDCT treated drills showed 35% and 15% less thrust force respectively when compared to DCT. The better performance can be attributed to the lack of internal residual stresses. Microstructure SEM images and Rockwell hardness testing was done to support the findings.

Evaluation of surface roughness in drilling particle-reinforced composites

Aluminum matrix composite materials being used in different sectors including automobile, aerospace, defense, and medical and are currently displacing unreinforced materials with their superior mechanical properties. The metal removal process of drilling is widely used in many structural applications. This study experimentally investigates the drilling characteristics of silicon carbide (SiCp)-reinforced Al 7075 composites produced by stir casting method. Also, two different drill materials with high-speed steel (HSS) and titanium nitride (TiN)-coated HSS carry out in drilling operation. The effect of operational parameters such as cutting speed and feed rate and materials parameters such as weight fraction of reinforcement and cutting tools on the surface roughness of drilled holes were evaluated in the drilling operations. The results of the drilling test indicate that the feed rate and cutting speed have a very strong effect on the surface roughness of matrix alloy and composite materials. The surface roughness ( Ra) values increased with increasing the feed rate and decreased with increasing the cutting speed. Under 0.10 mm/rev and 20 m/min drilling conditions and using HSS drill, surface roughness values for matrix, 5% SiC-, 10% SiC-, and 15% SiC-reinforced composites, were obtained 2.57, 2.59, 2.61, and 2.64 µm, respectively; besides, using TiN-coated HSS drill, surface roughness values were obtained 1.60, 1.63, 1.64, and 1.66 µm, respectively. An increase in the weight fraction of the abrasive SiC particle resulted in a very crucial deterioration quality of the drilled hole. TiN-coated HSS drills better performance exhibits than uncoated HSS drills for all the drilling operations about surface roughness properties. Short chip formations observed both the matrix alloy and the composite materials for two different drills in the drilling operations.

Study of the processing of small diagnostic creations on a fluid sourcing by spiral survivals

The article considers the features of the drilling process where there is a change in temperature, hole diameter, and displacement relative to the axis and the impact on the tool, when machining holes with high-speed steel drills there is wear of the transverse edge which is completely rounded to create a conical surface. There is a decrease in the negative value of the front corners on the transverse edge of the decrease in axial force, which led to a decrease in the intensity of wear of the transverse edge. In order of increasing axial force, respectively, and the intensity of wear of the transverse edge, were sharpened and recommended sharpening methods that provide high performance of the drill, the greatest stability, increased drilling accuracy, as well as the lowest cutting force. The analysis of influence of technological methods and ways and equipment on accuracy and quality of deep openings of small diameter is carried out. The effects of the method of lubricating coolant supply on the tool stability and processing productivity are investigated. The analysis of processing on the metal-cutting equipment with constructive development of the device is executed. Also, the stress-strain state of the drilling process by the finite element method with the analysis of external influences on the twist drill is carried out. The results of the research substantiate and recommend technological methods that reduce the deformation of the tool and, as a consequence, increase the quality and accuracy of the dimensions of deep holes of small diameter.

Drilling of nodular cast iron with a novel SiO2 coating deposited by sol-gel process in HSS drill

The present study proposes a novel coating applied on high-speed steel (HSS) drills, thinner and less expensive than the commercial ones. This new coating consists in a silicon dioxide (SiO2) deposited by sol-gel process, and its performance was studied by means of drilling tests in nodular cast iron. For comparison purposes, two other cutting tools were also evaluated: uncoated and TiN-coated by physical vapor deposition process. Four outputs were investigated: thrust force, hole average surface roughness, hole average diameter (DA), and tool wear (VBBmax). Analysis of variance (ANOVA) was applied to determine the influences of the coatings and drilling parameters on the cutting performances. The results indicated that the SiO2 coating achieved performances significantly superior to the uncoated tools. They also behaved close to the commercial TiN coating in some aspects. Scanning electron microscopy (SEM) analysis showed predominant flank wear in all the uncoated and coated tools. The “number of holes/maximum flank wear (VBBmax)” ratios were calculated, indicating a performance 315% better for the SiO2-coated tool when compared to the uncoated one. Therefore, the deposition of SiO2 by sol-gel method is a promising technique to coat rapidly and efficiently cutting tools, including for tools of complex geometries such as drills.

Lifetime and Performance Improvement of HSS Drill Bit by Titania (TiO2) Nano-Coatings and Cryogenic Treatment

The small and medium scale industry in drilling and cutting sector widely use cutting tools made by High Speed Steel (HSS). The improvement of lifetime of HSS drill bits helps these establishments to achieve product economy. The improvement in the performance and service lifetime of high-speed steel (HSS) twisted drill bits are studied by depositing Titanium dioxide (TiO2) nano-coatings using reactive dc magnetron sputtering Method. Pure titanium (99.99%) metal is used as target material for making nano-coatings in oxygen atmosphere. X-ray diffraction studies indicated change of phase of annealed samples compared to as-deposited coatings. X-ray reflection (XRR) measurements estimated nanocoating thickness on the HSS drill bit around 100nm. The lifetime of TiO2 nano-coated, and cryogenically treated nano-coated tools significantly improved compared to uncoated (bare) HSS drill bit. The tool life has been enhanced by about 16% when TiO2 nano-coatings were made on HSS drill bits. Further lifetime enhancement of 10% was observed when the nanocoated drill bit is given cryogenic treatment in liquid nitrogen. SEM images and EDS profiles are reported. The minimum surface roughness measured as 7.296x10-6m for TiO2 coated and cryo-treated HSS drill tool.

Measurement and analysis of thrust force and delamination in drilling glass fiber reinforced polypropylene composites using different drills

Fiber Reinforced Plastic (FRP) composites are widely used in various engineering fields and applications. FRPs were initially fabricated using thermoset polymers owing to ease of manufacturing. Of late, FRP based thermoplastics is gaining importance due to various factors such as impact resistance, recycling, and an absence of any chemical reaction. In the present investigation, Glass Fiber Reinforced Plastic (GFRP) laminates of woven glass fabric reinforcements with Polypropylene (PP) thermoplastic matrix is manufactured using film stacking technique. To analyze the performance in machining, drilling studies are carried out using a 6 mm diameter twist drill of High Speed Steel (HSS) drill, tipped carbide and solid carbide drill. The drilling experiments are conducted on a CNC Vertical Machining Centre (VMC) to measure and assess the drilling induced thrust force and the respective exit delamination. The drill spindle speed and feed rate are considered as process parameters. To correlate the process parameters with responses, the regression models are developed. The results indicate that the most significant control parameter for process responses and also it shows the developed regression models are highly reliable. The influence of drill materials on the performance of the responses is also discussed in detail.

Drilling of In-Line Compression Molded Jute / Polypropylene Composites

ABSTRACT Compression molding can be used to fabricate polymer composites with long-, short- and intermediate-length fibers. In-line compression molding reduces cycle time through a single-step process in which fibers are directly introduced into the molten polymer in the extruder which is directly molded. It eliminates additional stage of heating and processing and hence is preferred in industries. This paper deals with the influence of fiber type and direction, coupling agent, spindle speed, feed rate, drill material and diameter on delamination and thrust force in in-line compression molded jute/polypropylene. Thrust force was greater in the specimens with 30 wt% long fiber, in longitudinal direction processed without coupling agent and drilling with high-speed steel drill. Delamination was severe in chopped fiber composites, in longitudinal direction processed without coupling agent and with cobalt-high-speed steel tool. Effect of speed, feed, drill diameter and tool material was analyzed using ANOVA, signal-to-noise ratio and Grey relational analysis. Residual tensile strength reduced by 24.7% in the composites drilled using the optimized parameters.