Coated Carbide Drills Research Articles

Measurement and analysis of temperature, thrust force and surface roughness in drilling of AA (6351)-B 4 C composite

In the present study, the drilling is performed on AA (6351)–B4C composite to analyze the influence of cutting parameters on temperature, thrust force and surface roughness. The TiN coated carbide drill tools with varying point angle such as 90°, 118° and 135° are used to conduct the experiments. Initially, the temperature rise during drilling and the effect of temperature on the chip formation are investigated by contact and non-contact measurement techniques. The reduced temperature is achieved at lower spindle speed and feed rate conditions. However, the improper selection of point angle leads to tool wear and produces poor surface finish. In addition, the thrust force generation and the delamination of the drill holes are assessed by varying the input process parameters. The thrust force is low while drilling with 135° point angle tool, but produced higher delamination. Finally, the surface roughness is examined and the Scanning Electron Microscopic (SEM) images are utilized to observe the drill hole surface morphology of the composite.

Performance of TiAlN PVD Coated Carbide Drill when Drilling Titanium 6246 Alloy

This article describes the TiAlN PVD coated carbide drill tool performance after being used for drilling of Ti-6246 Titanium alloy. Every drill bit was used for single drilling and then being observed with SEM from flank and rake view. Taguchi method L18 design of experiment was used to find the optimum parameters. Wear was not found in this research, however, the tool delamination and tool chipping was evidenced, even if drilling only 10 mm depth. Tool experienced built-up edge in the outer blade, inner blade and at the chisel. This BUE can be seen at both view, i.e. rake and flank sides. BUE is the most dominant deterioration and inevitably in drilling this alloy, regardless the parameters applied. Tool delamination may occur during mechanism of peeling off the BUE. While chipping was related to higher feed rate, that may relate to high MRR. Analysing data using Minitab 17 shows that combination of drilling without cooling, 30 mm deep, cutting speed of 50 m/min and feed rate of 0.15 mm/min would result in the best performance of TiAlN tool for drilling Ti6246 as received.

The relationship of cutting force with hole quality in drilling process of AISI H13 steel

The harmony of the drilling machine-cutting tool-work piece is very important for producing the machine part with the ideal dimensions. For this purpose in this study, the effect of cutting forces on hole quality (surface roughness, diameter deviation and circular deviation) was investigated by 14 mm diameter uncoated and (AlCrN monolayer) coated carbide drills for drilling AISI H13 hot work tool steel on vertical machining center. Four different cutting speeds (60, 75, 90 and 108 m / min) and three different feed rates (0.15, 0.20 and 0.25 mm / rev) were used in the experiments. Cutting forces have been found to be effective in improving hole quality. Better hole quality has obtained with coated drills than uncoated drills in experiments. It has been observed that coated drills have the effect of improving the hole quality due to the operation with less cutting force and better chip evacuation.

Investigation of Effect of Graphite Particles on Drillability of Metal Matrix Composite

The present article investigates the effect of graphite particles in the drilling of hybrid aluminium matrix composites (AMCs) using TiN coated carbide drills. Materials used for the present investigation are Al6063-aluminum alloy reinforced with alumina of size 20 microns and graphite of an average size 75 microns, which are produced through stir casting method. Experiments are conducted based on Taguchi’s method L27 orthogonal array on a vertical machining centre. A model is developed to correlate the drilling parameters with burr height and surface roughness using regression analysis. The results indicate that the developed model is suitable for prediction of burr height and surface roughness in drilling of hybrid AMCs.The influence of different parameters on Surface roughness and burr height of Al6063/Al2O3p/Grp composites has been analyzed through ANOVA table and contour graphs.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.9724

Coated carbide drill performance under soluble coconut oil lubricant and nanoparticle enhanced MQL in drilling AISI P20

This research experimentally investigates the performance of a TiAlN coated carbide drill bit in drilling AISI P20 through two different kinds of lubricants, namely; soluble coconut oil (SCO) and nanoparticle-enhanced coconut oil (NECO) under minimum quantity lubrication system. The tool life and tool wear mechanism were studied using various cutting speeds of 50, 100 and 150 m/min with a constant feed of 0.01 mm/rev. Since the flank wear land was not regular along the cutting edge, the average flank wear (VB) was measured at several points using image analysis software. The drills were inspected using a scanning electron microscope to further elucidate the wear mechanism. The result indicates that drilling with the nanoparticle- enhanced lubricant was better in resisting the wear and improving the drill life to some extent

High-throughput Dry and Minimum Quantity Lubrication Drilling of Compacted Graphite Iron

This research investigates the high-throughput drilling of the compacted graphite iron (CGI), a high strength, lightweight material for automotive powertrain applications, at 26.5mm/s feed rate using 4mm diameter coated carbide drill. The CGI drilling experiments show that maximum 1740, 3150 and 2948 holes were drilled in two repeated tests under the dry, dry with through-the-drill compressed air, and minimum quantity lubrication (MQL) conditions. The Joule-Thomson cooling effect due to expansion of high pressure air from holes at the drill tip and mechanical effect of chip formation and evacuation are studied. Results demonstrate that high-throughput sustainable dry drilling of CGI is technically feasible.

Determination of Optimum Parameter Levels for Quality Characteristics in Conventional Drilling of Thick Polymeric Composites

Since literature on the machinability of non laminated composites is scarce, an investigation was extended away to study the machinability of thick non laminated Glass Fiber Reinforced Plastic (GFRP) composites and to compare the above with machinability of thick laminated composites. The composites with high fiber weight fraction were drilled with a special geometry coated carbide drill (Ratio drill). Taguchi’s orthogonal array and analysis of variance (ANOVA) were used to examine the influence of process parameters (feed and spindle speed) on quality characteristics (thrust force and torque). The optimum degree of process parameters towards aperture quality was obtained.

Burr Formation and Hole Quality when Drilling Titanium and Aluminium Alloys

Following a brief review of key factors affecting burr size and hole quality, the paper details experimental work involving the drilling of Ti-6Al-4V titanium alloy together with Al7010-T7451 and Al2024-T351 aluminium alloys. Chemical vapour deposited (CVD) diamond coated carbide drills were used for the aluminium workpieces while uncoated carbide tools were employed for the titanium material. An experimental design based on response surface methodology was implemented to identify the effects of cutting speed and feed rate (each at 3 levels) on burr size, hole diameter and out of roundness as well as tool flank wear. Exit burr size was smallest when operating at the intermediate feed rate level for all three workpiece materials, with reductions in burr height of up to 50% and 75% for the titanium and aluminium alloys respectively. Out of roundness did not exceed 0.03mm while the deviation on hole diameter was less than 0.04mm in all trials, even after drilling 60 holes.

Experiment Investigation of Hole Accuracy and Surface Roughness in Femur Bone Drilling Using Different Parameters

Success indicators in bone drilling include clean, good accuracy drilled holes without damage at the surrounding tissue. This study investigates the influence of cutting parameters in bone drilling against hole accuracy (enlargement diameter, circularity error, and cylindricity error) and surface roughness (Ra). A series of bone drilling experiments was carried out using femur bovine bone and without irrigation. Variations of drill type (high speed steel and coated and uncoated carbide) and cutting speed (19 m/min and 94 m/min) were used as input variables, while the feed rate (0.025 mm/rev) was constant. It was found that coated carbide drill results minimum magnitude on all machining responses. Type of tool gives significant effect on diameter enlargement and surface roughness, yet not on circularity and cylindricity errors. The range of cutting speed evaluated does not give significant effect on any surface integrity measures.

Analysis and optimization of drilling parameters for tool wear and hole dimensional accuracy in B4C reinforced Al-alloy

Cutting parameters were evaluated and optimized based on multiple performance characteristics including tool wear and size error of drilled hole. Taguchi's L27, 3-level, 4-factor orthogonal array was used for the tests. It is shown that generally abrasive wear and built up edge (BUE) formation were seen in the tool wear, and the corner wear was also of major importance. Flank wear of the cutting tool was found to be mostly dependent upon particle mass fraction, followed by feed rate, drill hardness and spindle speed, respectively. Among the tools used, TiAlN coated carbide drills showed the best performance with regard to the tool wear as well as hole size. Grey relational analysis indicated that drill material was the more influential parameter than feed rate and spindle speed. The results revealed that optimal combination of the drilling parameters could be used to obtain both minimum tool wear and diametral error.

Experimental investigation and multi-objective analysis on drilling of boron carbide reinforced metal matrix composites using grey relational analysis

In this study, machining parameters were evaluated and optimized with grey relational analysis in drilling B4C reinforced metal matrix composites (MMCs) produced by powder metallurgy. HSS, TiAlN coated and uncoated cementide carbide drills were used under dry cutting conditions. The drilling parameters such as feed rate, spindle speed, drill material and wt.% of B4C particles were optimized based on multiple performance characteristics including thrust force, torque and surface roughness. The experimental study showed that increasing the weight fraction of the B4C resulted in a considerable increase in the thrust force. Furthermore, average surface roughness of drilled hole decreased with increasing particle content for carbide tools and increased for HSS tools. Among the tools used, TiAlN coated carbide drills showed the best performance with regard to the surface roughness. Moreover, ANOVA analysis indicated that the most effective factor on grey grade was found to be weight fraction and followed by drill material, feed rate and spindle speed, respectively.

Optimization of cutting parameters on drill bit temperature in drilling by Taguchi method

In this study, the optimization of the cutting parameters on drill bit temperature in drilling was performed. Al 7075 work piece and the uncoated and Firex® coated carbide drills in the experimental were used. The optimization of the cutting parameters was evaluated by Taguchi method. The control factors were considered as the cutting speed, feed rate and cutting tool. Taguchi method was used to determining the settings of cutting parameters. The L18 orthogonal array was used in experimental planning. The most significant control factors affected on drill bit temperature measurements was obtained by using analysis of variance (ANOVA). Taguchi design method exhibit a good performance in the optimization of cutting parameters on drill bit temperature measurements. In addition, the empirical equations of drill bit temperatures were derived by using regression analysis. The obtained equations results compared with the drill bit temperature measurement results. The empirical equations results indicated a good agreement with experimental results.

EXPERIMENTAL AND ANALYTICAL STUDIES ON THE DETERMINATION OF HOLE QUALITY IN DRY DRILLING OF GFRP COMPOSITES

In this investigation nonlaminated Glass Fiber Reinforced Plastic (GFRP) composite rods made by pultrusion method with high fiber weight fraction was drilled with a special geometry coated carbide drill. The ovality of the drilled holes were measured using CMM. Taguchi’s orthogonal array and analysis of variance (ANOVA) were employed to study the influence of process parameters such as feed and spindle speed on ovality. The optimum level of process parameters towards minimum ovality were obtained to achieve defect controlled drilling of pultruded GFRP composite rods. Correlation for ovality with process parameters were established using a statistical software MINITAB 16 and found not to be fit. The influence of feed was insignificant and that of speed was significant on ovality of the drilled holes. The optimal process parameter levels within the range examined was identified as 0.05 mm/rev feed and 1000 rpm speed for drilling pultruded GFRP composite rods using 10 mm ratio drill. The influence of process parameters on hole quality in nonlaminated composite rods differs from that of in laminated composites.

Prediction of thrust forces and hole diameters using artificial neural networks in drilling of AISI D2 tool steel with cemented carbide tools

In this study, the effects of cutting speed, feed rate and different types of coating materials on thrust force and hole diameter were investigated in drilling of AISI D2 cold work tool steel. In addition, the thrust forces and hole diameters were predicted by artificial neural networks (ANN) using experimental data. Uncoated, TiN, TiAlN monolayer and TiAlN/TiN multi-layer coated cemented carbide drills with diameter of 5 mm were used in drilling experiments. The holes were drilled at different combinations of four cutting speeds (50, 55, 60, 65 m/min), two feed rates (0.063 and 0.08 mm/rev), and fixed depth of cut (7 mm). Experimental results showed that the lowest thrust forces and hole diameters were obtained with TiAlN/TiN multi-layer coated drills. After ANN training, it was found that the R2 values are very close to 1 for both training and test sets. RMSE values are smaller than 0.03, and mean error values are smaller than 5% for the test set. This case shows that ANN is a powerful method for prediction of thrust forces and hole diameters.

Performance and wear of coated carbide drill in machining of carbon fibre reinforced composite/titanium stack

In this research we investigate the performance of drilling process in carbon fibre reinforced composite (CFC) material, titanium alloy and the hybrid stack of these two materials, using coated carbide drill bit. We study the effect of the process parameters such as the feed rate and speed on the induced forces and torques, also on the wear of drill and surface roughness of the holes. In the composite material the percentage of surface damage in both drilling CFC on its own and drilling in stack form is estimated. Also, the effect of worn drill on the surface damage is identified. In the titanium, the burr formation in stack and non-stack form is investigated. The wear of the drill results in increased forces and torques required for drilling. This increases the surface delaminations substantially at the entrance in drilling of CFC. However, the surface roughness of the holes reduces with the wear of the drill in CFC drilling. Also, the surface delamination and surface roughness of the holes in the CFC whilst drilled in hybrid form reduces significantly. This is despite the increase of the forces and torques required in drilling CFC in stack form.

The Performances of Different Coated Carbide Drills when Drilling a Cast Nickel-Based Alloy

The performances of different coated carbide drills when drilling cast GH625 nickel-based alloy were evaluated in terms of tool wear and cutting force. Wear pattern observation and cutting force measurement were conducted under different cutting conditions. It was found that the drill coated with TiAlN/TiN showed the best overall performance among all the drill types tested. This drill type gave the longest tool life in terms of number of holes partly due to the excellent wear resistance of TiAlN/TiN multilayer. Besides, the thrust force and torque produced with this drill type were lower, which could be attributed to its good adhesion resistance and chip-ejection ability.

Optimization of Machining Parameters for Surface Roughness and Burr Height in Drilling Hybrid Composites

This article focuses on the multiple performance analysis in machining characteristics of drilling hybrid metal matrix composites produced through stir casting route. The desirability function-based approach is employed for the optimization of drilling parameters, namely, spindle speed, feed rate, and wt% of SiC based on the multiple performance characteristics including surface roughness and burr height. Material used for the present investigation is Al 356-aluminum alloy reinforced with silicon carbide of size 25 microns and mica of an average size of 45 microns. Experiments are conducted on a vertical machining center using the Box--Behnken experimental design (BBD) technique. The drilling test is carried out using coated carbide drill of 6 mm diameter. An empirical model has been developed for predicting the surface roughness and burr height in drilling of Al 356/SiC-mica composites. The optimization results showed that the combination of medium spindle speed, low feed rate, and high wt% of SiC is necessary to minimize burr height and surface roughness in drilling hybrid composites.

Performance and wear of coated carbide drill in machining of carbon fibre reinforced composite/titanium stack

In this research we investigate the performance of drilling process in carbon fibre reinforced composite (CFC) material, titanium alloy and the hybrid stack of these two materials, using coated carbide drill bit. We study the effect of the process parameters such as the feed rate and speed on the induced forces and torques, also on the wear of drill and surface roughness of the holes. In the composite material the percentage of surface damage in both drilling CFC on its own and drilling in stack form is estimated. Also, the effect of worn drill on the surface damage is identified. In the titanium, the burr formation in stack and non-stack form is investigated. The wear of the drill results in increased forces and torques required for drilling. This increases the surface delaminations substantially at the entrance in drilling of CFC. However, the surface roughness of the holes reduces with the wear of the drill in CFC drilling. Also, the surface delamination and surface roughness of the holes in the CFC whilst drilled in hybrid form reduces significantly. This is despite the increase of the forces and torques required in drilling CFC in stack form.

Experimental Investigation and Analysis of Thrust Force in Drilling Hybrid Metal Matrix Composites by Coated Carbide Drills

Hybrid metal matrix composites (MMCs) find diversified applications in many engineering fields and are very important in the recent development of material science. The present article investigates the effect of thrust force in the drilling of hybrid MMCs using coated carbide drills. Materials used for the present investigation are Al 356-aluminum alloy reinforced with silicon carbide of size 25 microns and mica of an average size 45 microns, which are produced through stir casting route. Experiments are conducted on a vertical machining centre using the central composite design technique. A model is developed to correlate the drilling parameters with thrust force using response surface methodology (RSM). The results indicate that the developed model is suitable for prediction of thrust forces in drilling of hybrid MMCs. Analysis of the drilled surface of Al356/SiC-Mica composites was done using scanning electron microscope (SEM). The influence of different parameters on thrust force of Al356/SiC-Mica composites has been analyzed through contour graphs and three-dimensional (3D) plots.

Surface Integrity in MQL Drilling Nickel-Based Superalloy

Nickel-based superalloys remain the most widely used of all materials in aerospace industry, contributed over 50 % of the weight of a jet engine. In machining of any jet engine components, it is necessary to satisfy the surface quality or surface integrity requirements to facilitate high reliability components. In the present study, surface integrity of Inconel 718 was studied when drilling under different lubricants. The holes were drilled individually using indexable AlTiN coated carbide drill under minimum quantity of lubricant (MQL) conditions. The results demonstrated that the machining conditions and lubricants strongly influence the surface integrity. The surface roughness decreases with the increase in cutting speed and increases with the increase in feed rate. Microhardness profiles indicated that the subsurface deformation extends up to a 100 and 150 μm for palm oil and synthetic ester, respectively underneath the machined surface. Pit holes, cavities, grooves, microcracks and surface smearing were the dominant surface damages criteria for all cases.