Tool Point Angle Research Articles

Optimization of Micro-Drilling of Laminated Aluminum Composite Panel (Al-PE) Using Taguchi Orthogonal Array Design.

Aluminum Matrix Composite (AMC) represents an innovative class of materials that is extensively utilized in industries such as automotive, defense, aerospace, structural engineering, sports, and electronics. This study investigates the thrust force, exit burr formation, changes in the micro-tool, and drilled hole diameters during the micro-drilling of an aluminum-polyethylene composite panel (Al-PE). The panel consists of 3501 series aluminum skin materials bonded to a polyethylene (PE) core. Micro-drilling test parameters were designed using Taguchi's L16 (42 23) orthogonal array. Tests were conducted with five control parameters: cutting speed with four levels (10 m/min, 20 m/min, 30 m/min, 40 m/min), feed rate with four levels (0.5 µm/rev, 1 µm/rev, 2 µm/rev, 4 µm/rev), the tool diameter with two levels (0.7 mm, 1 mm), and tool point angle with two levels (100°, 140°) using both AlTiN-coated and uncoated drills. The maximum thrust force (Fz), maximum burr height, and changes in both the drill tool and hole diameters were measured for analysis of variance (ANOVA). The results showed that, in terms of impact on Fz, tool point angle had the highest positive influence (64.54%) on the micro-drill at the entrance of composite (upper aluminum plate). The cutting speed had the highest positive influence (45.32%) on the tool in the core layer (PE core layer). The tool point angle also had the highest positive influence (68.95%) on the micro-drill at the lower layer of the composite (the lower aluminum plate). There was noticeable chip adhesion on the major cutting edge and nose area under micro-drilling conditions with higher thrust forces and burr height. The AlTiN coating had a positive effect on tool wear and hole diameter deviations, but it adversely affected the burr height.

Analysis of the Effect of Tool Geometry and Hole Quality on Drilling Carbon-Fibre Reinforced Polymer Composite Using ANSYS

This study focused on the analysis of the effect of tool geometry and hole quality on drilling carbon-fibre reinforced polymer (CFRP) composite using ANSYS. The experiment was conducted on computer numerical control machine (CNC) using high speed steel (HSS) twist drill bit and HSS-COBALT drill type. Taguchi L9 orthogonal array was used for the optimization analysis. Analysis of variance (ANOVA) was employed to determine the most significant control factors affecting the drilling process. The machining parameters involving tool type, point angle, spindle speed and feed rate were selected as control factors. While the dependable variables on workpiece were cutting force, stress and strain. The main interaction effect of the input variables on the predicted responses was investigated. The ANOVA/F-test results for cutting force with the contribution of each machining parameters revealed that the cutting speed was the dominant factor influencing cutting force developed with a contribution of 57 percent, The second factor affecting cutting force developed was point angle with a contribution of 5.7 percent, while f eed rate had the least effect on cutting force developed where its contribution of 1.4 percent. Based on the results observed, the optimal machining parameters that produced minimum stress was observed with HSSCOBALT drill at 118 degrees of point angle, 300 mm/min of feed and 500 rpm of speed. Also from Taguchi results, the optimal combination of process parameters to obtain maximum strain with HSS drill, 135 degrees of point angle, and 300 mm/min of feed and 1500 rpm of speed produced the optimal drilling condition for CFRC polymer within the scope of this research work.

PTFE in Wet and Dry Drilling: Two-Tier Modeling and Optimization through ANFIS

This research is done to determine the optimum parameters to drill polytetrafluoroethylene (PTFE) and to investigate the effect of two-tier modeling for enhanced response in optimization. RSM model was done with L27 experimental design, considering speed (N), feed (f), and tool point angle (Ɵ). RSM data were further trained and tested using the Adaptive Neuro-Fuzzy Inference System (ANFIS), and β coefficient values were restructured to form revised RSM model. Both nonrevised RSM model and revised RSM model were used in Genetic Algorithm to locate the minimum surface roughness. ANFIS revised RSM model deviates from the experimental results by 2.6% and 2.86% for dry and wet condition; meanwhile, nonrevised RSM model deviates by 4.76% and 4.94%, respectively. The research concludes that two-tier modeling using RSM and ANFIS is better. Spindle speed of 1656 rpm, feed rate of 0.05 mm/min, and point angle of 100° are the optimum conditions to drill PTFE material where the best surface quality of 0.68 μm at wet drilling can be achieved.

MEASUREMENT OF THE GEOMETRY OF MANUFACTURED DRILLS USING OPTICAL SCANNING

This article deals with the control of the geometry of manufactured tools. The geometry of the cutting tool has a great influence on the machining process. One of the processes of manufacturing cutting tools is grinding. Grinding cutting tools is a complex process after which it is necessary to check the geometry of the tools. Five solid drilling tools were manufactured for the experiment. The measured parameters were tool diameter, helix angle, point angle, rake angle, relief angle and core diameter of the cutting tools. The geometry of the cutting tools was measured on a non-contact structured 3D scanner ATOS Triple Scan light. The measurement results were evaluated using GOM software. The scanning results were compared with the geometry measurement on an optical measuring device Zoller Genius 3s. It has been found that the use of a non-contact structured 3D scanner is suitable for checking the geometry of cutting tools. Furthermore, the article deals with the roughness arising when grinding a sintered carbide flute.

The Effect of Machining Parameters and Drill Point Angle on the Temperature Distribution in AISI 304 Stainless Steel During Dry Drilling Operation

In this research work, the influence of cutting parameters and drill point angle on the temperature distribution in dry drilling of stainless steel AISI 304 was numerically investigated by using FE method based on DEFORM-3D V.11 commercial software. Two cutting tools of 10 mm diameter but different in point angles, one is 110° and the other is 118°. These tools were imported from specific website in a format of STL and inserted in the program during modeling of cutting tools. The material of the cutting tools is selected as high-speed steel. The workpiece model is created as cylindrical shape with 50 mm diameter and 5 mm thickness. The cutting parameters are selected as three cutting speeds (100, 200, and 300) rpm, with three feed rates (0.15, 0.25, and 0.35) mm/rev. The depth of hole is fixed for all simulations (3 mm). The percentage of increase or decrease in the resulted temperature according to the various cutting parameter was also calculated and discussed. The best cutting performance of tools according to the change of point angles was also investigated. The results provided a significant influence of cutting speed and tool point angle on the temperature generated in the machined models and very small influence of feed speed on the workpiece temperature.

Experimental Investigation of Thrust Force, Delamination and Surface Roughness in Drilling Hybrid Structural Composites.

Filled hybrid composites are widely used in various structural applications where machining is critical. Hence, it is essential to understand the performance of the fibre composites’ machining behaviour. As such, a new hybrid structural composite was fabricated with redmud as filler and sisal fibre as reinforcement in polyester matrix. The composite was then tested for its drilling performance. A comprehensive drilling experiment was conducted using Taguchi L27 orthogonal array. The effect of the drill tool point angle, the cutting speed, the feed rate on thrust force, delamination, and burr formation were analysed for producing quality holes. The significance of each parameter was analysed, and the experimental outcomes revealed some important findings in the context of the drilling behaviour of sisal fibre/polyester composites with redmud as a filler. Spindle speed contributed 39% in affecting the thrust force, while the feed rate had the maximum influence of ca. 38% in affecting delamination.

The impact of tool point angle and interlayer gap width on interface borehole quality in drilling CFRP/titanium stacks

Although substantial research work has been conducted in order to understand and improve the drilling of multi-material aerospace stacks, some key aspects related to process and tool parameters and their impact on the interface quality still need to be addressed. This paper reports on the research conducted to investigate the impact of tool point angle and interlayer gap width on borehole quality, focussing on the interface region. A number of drilling tests were carried out using tools with different point angles and CFRP/titanium stacks with different interlayer gap widths. The results show that the damage on the CFRP interlayer surface is caused by the drilling of the titanium layer, as some of the upwards-travelling titanium chips penetrate into the stack interface. An increase in tool point angle results in larger entry burrs on the titanium interlayer surface, which is attributed to the correlation between tool point angle and thrust force and the capability of tools with low point angles to remove damage generated by surface skidding. The introduction of an interlayer gap promotes the ingress of titanium chips into the stack interface, thereby leading to more pronounced interface damage.

Process parametric optimization in drilling of CFRP composites using GRA method

In the modern world, lightweight fibrous composites materials with high mechanical properties are the first choice for structural design purpose. Excellent mechanical properties and easy to make and shape quality make it the prime substance for aeronautics as well as automobile manufacturing units. However, drilling of these non-homogenous fibrous polymers is quite tricky in compare to the other traditional metal. In this paper, eighteen different sets of the parametric combination were derived, using Taguchi’s L 18 orthogonal array. Grey relational analysis (GRA) has been used to find the optimal drilling parameter setting by optimizing the three performance characteristics, like thrust force, torque, and delamination factor. The axial thrust force was found to be the most influential feature in predicting delamination factor. However, the thrust force was maximum at high feed and low spindle speed and higher tool point angle. Analysis of variance is also used for predicting the most contributing parameter and it was found out that, feed rate has the maximum impact in drilling carbon fiber reinforced plastics (CFRP).

Study on the influence of tool point angle on ultrasonic vibration–assisted drilling of titanium alloy

The paper presents simulation and experiment to analyze the thrust force and cutting heat of conventional drilling (CD) and ultrasonic vibration–assisted drilling (UAD) with different tool point angles. The HAAS vertical machining center combined with ultrasonic vibrating shank has been used to study the hole quality in drilling of Ti-6Al-4V material without cooling, including surface roughness, residual stress, exit burrs, and tool wear. Stimulation results show that the thrust force and cutting heat can be greatly reduced by applying ultrasonic assistance. An increase in tool point angle will cause the thrust force and cutting heat to increase in varying degrees. On the other hand, the experimental results show that the thrust force and cutting heat are consistent with those obtained in the simulation, and the surface roughness has been reduced accompanied by change in surface topography after UAD. Moreover, the optimal parameters for the minimum surface roughness have been found by orthogonal test. It is observed that the residual compressive stress has been improved effectively in UAD and become a maximum at the tool point angle of 130° in CD and UAD. According to a lot of experiments, the height of the exit burr can be also significantly reduced by UAD and reaches the minimum at the tool point angle of 130°. Results show that UAD is capable of reducing tool wear greatly, and the minimum tool wear rate has been obtained when the tool point angle is 130°. Besides, the rate of such tool wear generally increases if the number of the processed holes exceeds 30.

Processing of functionally graded aluminum composite brake disc and machining parameters optimization

Abstract This study aims at fabrication and characterization of silicon carbide reinforced functionally graded aluminum composite brake rotor disc by centrifugal casting and optimization of machining parameters such as tool speed, feed, point angle and machining zones with varying volume fraction of reinforcements during drilling of brake disc using Grey Relational Analysis (GRA). The functionally graded structure is formed in the brake disc by centrifugal casting process, where the centrifugal force migrates the hard SiC particles from inner region of disc towards outer braking areas of the discs, which enhances the hardness, strength and wear resistance. The characterization of brake disc shows higher hardness and compression strength towards the braking area closer to outer periphery due to enrichment of SiC particles. The optimization of machining parameters is very much important in functionally graded material (FGM) components, since the hardness and properties vary at different zones. The tool feed rate and zones of the FGM brake disc are the major factors that significantly influences the drilling process.

Assessment of the Surface Roughness and the Delamination in Drilling Hole of Al/SiCp MMCs

In this research, the analysis of the experimental results has been carried out to study the influence of the following input process parameters; three of the cutting speeds, five of the feed rates and five of the drill tools (HSS - different point angles-same diameter) on the process responses, i.e. the delamination factor (df) and the surface roughness (Ra) of the drilled hole. The drilling has been carried out on the plate of AL/SiCp MMC, with using three of volume fraction ratios. The results indicated that the delamination factor (df) is increased with the increase of; the feed rate, the tool point angle, the cutting speed and with the increase of volume fraction ratios. In addition, the surface roughness (Ra) of the drilled hole is increased with the increase of; the feed rate, the tool point angle and with the increase of volume fraction ratios, but decreases with the increase of the cutting speed.

Prediction of surface quality and optimization of process parameters in drilling of Delrin using neural network

The high-temperature polymers like Acetal homopolymer (Delrin) currently have a wide variety of use. They are quite often utilized in traditional components to reduce weight, cost or meet a specific application requirement, and so on. Some of preferred uses of such polymers include aircraft interiors, wire insulation, wire couplings and fixtures, and so on, particularly at high-temperature applications. The machining process like drilling may affect the near net shape of the final product. This experimental study is done through modeling and optimization for identifying the suitable tool and optimum parameters for drilling of Delrin polymer under dry conditions to achieve high surface finish. The three levels of parameters such as spindle speed ( N), feed rate ( f), and tool point angle ( Θ) are taken as control parameters of the response variable. Two different commercially available tool materials namely high-speed steel drill tool and solid carbide tool are accounted in experiments. L27 orthogonal array is initially taken for the experimentation in CNC turning center with horizontal drilling setup. Artificial neural network is employed to sample, train, and test the input parameters in order to lessen the experimental error and measurement error of response variables. Response surface models are developed and optimal parameters toward the surface quality of the hole are determined through the desirability function approach. It is found that the surface generated under dry mode with speed of 1026 r/min, feed of 0.1 mm/min, point angle of 118° recorded the surface roughness of 0.699 µm, which is considered to be the best for drilling Delrin material.

Prediction of Thrust Force and Torque in Drilling of Glass Fiber Reinforced Plastic Using Mechanistic Force Model Approach

High strength to weight ratio along with non-corrosive characteristics make glass fiber reinforced plastics (GFRPs) most promising material in aerospace, navel, automobile and construction sector. However its non-homogeneous and anisotropic nature leads to unfavorable hole quality when subjected to drilling. Among all the drilling induced defects delamination has received considerable attention. Delamination of the material at drill entry occurs above critical torque where as it occurs above critical thrust force at drill exit which adversely affect product quality and results into rejection. Paper presents, a mechanistic approach to develop cutting force models to predict thrust force and torque in GFRP drilling. The mechanistic approach exploits different set of fundamentals of the process including speed, feed rate and tool geometry. Tool point angle, diameter and primary cutting edge effects are mainly considered in this model to predict thrust forces and torque for cutting speed and feed rate combinations. Drilling experiments were conducted on unidirectional glass fiber with stacking sequence of (0/90) sheet with carbide drill to study the influence of various combinations of speed and feed on thrust force and torque. Proposed model is validated for the drill point angle, drill diameter and primary cutting edge of drill bit for GFRP drilling over a wide range of machining conditions.

Drilling optimization of woven CFRP laminates under different tool wear conditions: a multi-objective design of experiments approach

The cutting tool geometry is known to be an influential factor on damage induced during drilling of composite materials. Conversely, the geometry of the tool is affected under multiple drilling cycles due to highly abrasive nature of fibers. Building on earlier reports, the aim of this work is to create a better understanding of cutting parameters on the quality of drilled woven carbon fiber reinforced polymer (CFRP) laminates, given different tool wear conditions. Namely, a full factorial design of experiments has been conducted to quantify the significance of each process parameter (cutting velocity, feed rate and tool point angle), as well as their interactions, on the generation of entry- and exist- delaminations as well as the thrust force for different tool types. Finally, using a response surface methodology, a multi-objective optimization strategy has been presented to select optimum ranges of design parameters that can minimize the aforementioned output variables collectively. Such knowledge may be useful to explore further improvements toward defect-free drilling of woven CFRP composites.

Fuzzy Based Optimization of Thrust Force and Torque during Drilling of Natural Hybrid Composites

This investigation was done to study machinability during drilling on sandwichlaminates. Vetiver and jute were used as natural fibers and glass was used as synthetic fibers in vinyl ester matrixin the form oflaminatesby varying the fiber content in each laminate.The laminateswere drilled during which spindle speed, spindle feed rate, tool point angle and sample laminate weremodified using D-optimal design technique. During drilling of each hole, thrust force impressed and torque developedwere noted as outputs.The outputswere optimized to observe best drilling conditions.A fuzzy model was created and its predictions for trialconditionswere noted. A comparison between trial values, regression values and fuzzy values was made. Confirmatory trialswere madefor optimumset of runs and outputswere again noted.The percentage of error between the model, confirmatory trials and fuzzy were found to be meagre and hence concluded that the optimization was satisfactory.

OPTIMISING DRILLING PARAMETERS OF GFRP BY USING GREY RELATIONAL ANALYSIS

Glass fiber reinforced polymer (GFRP) composite constitutes the current trends in the composite technology and machining of these materials make a challenging task. Drilling of GRPF can cause many problems if not optimized. In this study, composite undergo drilling and L27 orthogonal array is used for determining delamination and surface roughness. Relationships are developed between parameters. In drilling, spindle speed, tool point angle and feed rate are combined to know the optimal parameters. Grey Relational Analysis was performed to observe the effect of parameters and its interaction. Experiment results reveal that spindle speed is the most significant factor while point angle contributes to the least.

Surface and Sub-surface Analysis of Hybrid Polymer Composites during Machining Operations

The present work is carried out to investigate the delamination defects and surface roughness during drilling on newly developed biodegradable hybrid composite laminates. The natural hybrid composite consists of Natural vetiveria zizaniodes (vetiver) and synthetic glass are used as reinforcements in vinyl ester resin to form four composite specimens based on varying the fiber compositions in each specimen while the resin content is kept as a constant. The specimens are subjected to drilling operations during which machining parameters like speed, feed rate, tool point angle and work sample are varied between four levels to form 44 D-optimal factorial design. After 28 runs the delamination factor at the entrance and exit of hole and machined sub- surface roughness are measured as responses. The responses are analyzed using response surface method and non-linear regression equations are developed. Optimization on the data resulted in selection of best level of speed, feed and tool angle for the selected samples. Confirmatory runs have been conducted and the responses are measured. Average error between the model and confirmatory run was found minimal and hence the optimization was found to be satisfactory.

Modeling and multi-constrained optimization in drilling process of carbon fiber reinforced epoxy composite

The goal of this study is to present a methodology for the determination of the optimal cutting parameters (spindle speed, feed rate and tool point angle) during the drilling process of carbon fiber reinforced polymer composites (CFRP) to maximize the material removal rate by considering surface roughness, delamination and thrust force as the constraints through coupling Response Surface Method (RSM) and Genetic Algorithm (GA). In this regard, the advantages of statistical experimental design technique, experimental measurements, Response Surface Method (RSM) and the genetic optimization method are exploited in an integrated manner. To this end, the experiments on CFRP were conducted to obtain surface roughness, delamination factor and thrust force values based on the full factorial design of experiments, and then analysis of variance (ANOVA) is performed. The predictive models for outputs were created using Response Surface Method (RSM) taking advantage of the experimental data. Material removal rate constituted the main function for the genetic algorithm, and thrust force, delamination, and surface roughness were applied as the constraints of the GA function. The function was optimized by the GA code, and finally, the optimum variables were obtained, and the results of the GA were tested experimentally. It can be clearly observed that good agreement exists between the predicted values and the experimental measurements.

Study of Manufacturing Defects and Tool Geometry Optimisation for Multi-Material Stack Drilling

In the aeronautic industries, composite materials are increasingly being used for structural parts. Carbon Fibre Reinforced Plastics (CFRP) are often used in combination with metallic materials, mostly aluminium alloys. This raises new problems in aircraft assembly when it comes to machining the holes for thousands of fasteners. The preferred method for this is a one-shot drilling-reaming-countersinking operation usually using a power tool and with the need to respect tight dimensional and geometric specifications. The solutions proposed so far with existing cutting tools, involving reduced feed rate, are unsatisfactory from an economic point of view. This study first focuses on identifying machining defects and difficulties encountered during drilling of aluminium/CFRP stacks. Then, based on the results of different works on drilling [1,3], an experimental study is proposed to define the critical macro-and micro-geometric parameters of a carbide drill. The criteria relate to the fragmentation of the metallic chips, burr avoidance and zero damage to the CFRP. The first results obtained with the new generation cutters developed show the importance of a constant axial rake angle and of the tool point angle in the chip fragmentation phenomenon but also in preserving the health of the CFRP material. The influence of the constant rake angle on the axial forces generated is also shown. Finally, an optimal combination of the tool geometrical parameters is achieved in order to obtain the expected results.

Development of Empirical Models for Surface Roughness Prediction in Finish Turning

Surface roughness plays an important role in product quality. This paper focuses on developing an empirical model for the prediction of surface roughness in finish turning. The model considers the following working parameters: workpiece hardness (material); feed; cutting tool point angle; depth of cut; spindle speed; and cutting time. One of the most important data mining techniques, nonlinear regression analysis with logarithmic data transformation, is applied in developing the empirical model. The values of surface roughness predicted by this model are then verified with extra experiments and compared with those from some of the representative models in the literature. Metal cutting experiments and statistical tests demonstrate that the model developed in this work produces smaller errors than those from some of the existing models and have a satisfactory goodness in both model construction and verification. Finally, further research directions are presented.