Thrust Force In Drilling Research Articles

Sustainable Cutting Environment Evaluation for Drilling of Aluminum A380 Foam Produced by Semisolid Recycling

The development of sustainable cooling technologies and increased concern for recycled materials will affect the reduction of greenhouse gas emissions, which primarily originate from the production industry. In this research paper, a twofold contribution to sustainability is made through the efficient application of a workpiece, obtained by recycling waste in the form of metal chips, and the machining of the obtained workpiece by using alternative cooling techniques comparing them to cutting fluids. Minimum quantity lubrication and cold compressed air cooling were selected as two sustainable, alternative cutting environments. Using Taguchi’s L9 orthogonal array, the influence of cutting speed, feed rate and cutting environment on drilling thrust force, built-up edge formation and hole deviation was observed. Using the analysis of variance method, feed rate was identified to have the highest influence on the output parameters (31%), followed by cooling and lubrication techniques (18%) and lastly by cutting speed (5%). Based on the grey relation analysis, optimal controllable factors were identified. This analysis indicated that low cutting speeds and feed rates, coupled with the MQL cutting environment, produced the lowest thrust force, deviation of hole and built-up edge formation.

Stacked generalization ensemble learning strategy for multivariate prediction of delamination and maximum thrust force in composite drilling

The complexity of drilling carbon fiber reinforced polymers (CFRP) requires accurate predictive models. This study addresses the challenge using an ensemble machine learning (ML) approach with stacked generalization. The model captures the relationships between key input variables—such as graphene nanoplatelet (GNP) content, ultrasonic assistance, tool type, stacking sequence, and feed rate—and output parameters, specifically thrust force and delamination. A nested feature scoring (NFS) method was employed for importance analysis, revealing tooling type and feed rate as key features for minimizing delamination and reducing thrust force, respectively. The machinability results revealed that ultrasonic drilling lowered thrust force by improving chip evacuation and reducing fiber breakage. HSS tools with cobalt content, alongside symmetrical stacking sequence, helped to further minimize both thrust force and delamination. However, the inclusion of GNPs led to an increase in thrust force and delamination, attributed to the increased strength of the CFRP/GNP composite. The process involved meticulous training, resulting in four optimal-fit models serving as inputs for the stacked meta-model. Iterative enhancements fortified the ensemble robustness, with fine-tuning of hyperparameters through Bayesian optimization. The ensemble superiority over individual models manifested in a remarkable reduction of mean absolute error (MAE) and root mean squared error (RMSE) by up to 97% and 124% for delamination, and 205% and 154% for thrust force, compared to the best base learner. Visual and statistical assessments effectively illuminated the intricate interactions between variables in the drilling process. The methodology resulted in a highly adaptable predictive model with applications across diverse manufacturing contexts.

A novel real time sensing framework for assessment of thrust force in drilling of composites using Taguchi and NSGA-II

Monitoring thrust during drilling operations is critical to optimizing drilling parameters and ensuring safe and efficient drilling. In this study, we will monitor variations in thrust force during the drilling process using a sensor coated with carbon black. These sensors measure changes in electrical resistance when the sensor is subjected to a mechanical load, such as drilling force. Carbon black at 5 wt% was used, which was embedded in a fiberglass composite. For this study, an orthogonal arrangement of Taguchi’s L27 sequence was used, with drill diameter D, feed rate F, and spindle speed S as machining parameters. The thrust force was measured with a force dynamometer and the resistance change was measured simultaneously with the developed new system. Analysis of variance was used to find the optimal parameters, and in this study, a mathematical model was proposed to measure the thrust force directly using the electrical resistance detected. NSGA-II algorithm was used to predict solutions for the given parameters for comparison. A comprehensive way of drilling process and data-driven decisions to improve drilling performance and safety was studied, and a correlation between actual thrust and calculated thrust of 0.91 was found. The proposed system was able to monitor and continuously record thrust force in real time during drilling, with electrical resistance as the most important factor with an error percentage of less than 8% compared to the NSGA-II predictions of less than 5%.

Improving hole quality of thick CFRP laminates through a laser-mechanical compound drilling process

Conventional mechanical drilling of thick carbon fiber reinforced plastic (CFRP) composite laminates is prone to machining-induced defects such as burrs, delamination, and severe tool wear. However, pulsed laser drilling as an improved strategy results in hole taper and the formation of a heat-affected zone (HAZ). Herein, a new laser-mechanical composite drilling process is proposed, which combines the advantages of pulsed laser drilling for avoiding tool wear and twist drilling for achieving high dimensional accuracy, significantly improving the drilling quality of thick CFRP laminates. The evolution mechanism of the hole taper and HAZ with processing conditions in pulsed laser drilling is investigated. Furthermore, a theoretical model is established to reveal the material removal mechanism during the reaming process. The thrust force variation, drilling quality and tool wear are analyzed and verified by comparative experiments. The results show that due to the shielding effect from the surface materials, the maximum hole taper and HAZ at the hole exit reach up to 37.5° and 650 μm, respectively, which can be removed effectively by subsequent reaming operations. Due to its small amount of material removal, the peak thrust force and the average thrust force in laser-mechanical drilling are only 53.8 % and 37.6 % of the critical thrust force of delamination, respectively, which can effectively inhibit delamination. Compared with direct twist drilling, the average wear of the main cutting edge in laser-mechanical drilling is decreased by 60.87 %, which greatly reduces the size of the delamination by 55 %.

Prediction of thrust force in indexable drilling of aluminum alloys with machine learning algorithms

The thrust force has a direct effect on important output responses such as surface roughness, power consumption, and tool wear. The measurement process for thrust forces is very time-consuming and costly. Low success rates are achieved in the estimation of thrust force. The mechanical properties and chemical composition of the workpiece material were not taken into account as input properties in the previously established models. However, these features are of high importance in the formation of the thrust force. In this study, it is aimed at estimating the thrust force with the least input feature with a high success rate by establishing single and hybrid models with different machine learning algorithms. As a result, the thrust force can be successfully predicted by machine learning algorithms by entering two properties. Successful thrust force estimation will provide more accurate process planning, material selection, and optimization.

Prediction of Thrust Force and Torque for High-Speed Drilling of AL6061 with TMPTO-Based Bio-Lubricants Using Machine Learning

This study was designed to examine the effects of a trimethylolpropane trioleate (TMPTO)-based lubricant on thrust force and torque under the high-speed drilling of Al-6061 as an effective environmentally friendly cutting fluid. The tribological performance of three lubricant blends was evaluated based on ASTM standards. TMPTO base oil, notably enhances load-carrying capacity under extreme pressure conditions, with a seizer load of 7848 N. The best-performing oil was further optimized using a Taguchi-based design experiment to investigate the effect of different additive concentrations on thrust force and torque under actual contact conditions. Experiments were conducted using three critical machining parameters: additive concentration, spindle speed, and feed rate. The results of the ANOVA analysis reveal that spindle speed contributes most substantially (62.99%) to torque, with feed rate (23.72%) and additive concentration (7.74%) also showing significant impacts. On the other hand, thrust force is primarily influenced by feed rate (73.52%), followed by spindle speed (16.82%), and additive concentration (6.28%). Furthermore, a machine learning model was developed to predict and compare a few significant aspects of high-speed drilling machinability, including thrust force and torque. Three different error metrics were utilized in order to assess the performance of the predicted values, namely the coefficient of determination (R2), mean absolute percentage error (MAPE) and mean square error (MSE), which are all based on the coefficient of determination. Compared to other models, decision tree produces more accurate prediction values for cutting forces. The present study provides a novel approach for evaluating the most promising biodegradable lube oils and predicting cutting forces by formulating a perfect blend.

Modeling and estimation of thrust force, torque, and surface roughness in indexable drilling of AA6061-T651 with Taguchi, ANN, and ANFIS

Modeling and estimation of thrust force, torque, and surface roughness in indexable drilling of AA6061-T651 with Taguchi, ANN, and ANFIS

Optimization of cutting parameters by thrust force and time for drilling of aluminum 2024 T351

Abstract In this study, the cutting parameters were optimized according to the thrust force and operation time in the drilling of Al 2024 T351 alloy, which is preferred in the aerospace industry and therefore subjected to thousands of drilling processes with liquid cooling. Cutting speed (70, 90, and 110 m min−1) and feed rate (0.08, 0.1, and 0.12 mm tooth−1) were considered cutting parameters. Experiments were performed three tool types (HSS, HSSE-Co5, HSSE-Co5 TiAlN coated). Taksan TMC-700 V CNC vertical machining center with FANUC control panel was used for drilling, and ESIT AX3 load cell and NI cDAQ-9188, data acquisition system, were used for data collection. Signal noise was reduced by applying the exponential smoothing method to all force data obtained in the experiments. The maximum forces in the machining direction (z-axis) were determined for each hole. The time was calculated during the computer aided manufacturing process. Response surface optimizations, variance analyses (ANOVA), and regression analyses were performed using these determined maximum thrust forces and measured time.

Evolutionary Algorithms for Optimization of Drilling Variables for Reduced Thrust Force in Composite Material Drilling

This study aims to optimize drilling variables to reduce the thrust force required for drilling composite materials. The optimization process involves using evolutionary algorithms such as particle swarm optimization (PSO) and genetic algorithm (GA) to determine the best combination of drilling parameters, including drill speed, feed rate, and point angle. The objective is to minimize the thrust force required for drilling while maintaining the desired quality of the drilled holes. ANOVA and regression analysis is implemented to discuss the impact of drilling variable on the thrust force. The results demonstrate that the proposed approach is effective in reducing thrust force and improving drilling efficiency. The optimized drilling parameters obtained can be used to enhance the performance of composite material drilling processes. Performance output of both algorithms for optimization of problem is discussed in detail.

Analysis and modelling of thrust force in drilling of basalt and carbon fibre-reinforced polymer (BFRP and CFRP) composites

Currently, the use of sustainable products and technologies is growing; consequently, mineral-origin basalt fibre-reinforced polymer (BFRP) composites are becoming more popular in industries. Although BFRP parts require mechanical drilling operations for manufacturing holes for assembly, many challenges make the drilling process difficult. Considering that the cutting force is one of the main parameters characterising the drilling process, this study aims to analyse the influence of feed (mm/rev) and cutting speed (m/min) on the thrust force and model the thrust force in the drilling of BFRP composites through response surface methodology (RSM) and advanced statistical modelling methods. In order to determine main and interaction effects and to calculate the regression coefficients and model parameters, mechanical drilling experiments were performed, and the thrust force was recorded. The raw force data were processed using fast Fourier transformation-based low-pass filtering, and then the calculated thrust force parameters were evaluated relative to various feeds and cutting speeds. In addition, results were compared with those of carbon fibre-reinforced polymer composites. The results of the validation experiments show that both RSM and advanced statistical models accurately predict the thrust force in BFRPs of 96.74% and 95.01%, respectively. However, the advanced statistical model can describe not only the maximum values of the force but also its characteristics at a coefficient of determination of 0.68.

Burr Formation in drilling of aluminum plates under cutting conditions modelled for manual operation

Aluminum alloy is widely used in aircraft structural components. The high cutting force in the conventional machining often causes the burr formation in the machined parts. To overcome the problems, machining method with low cutting force are recommended. In this study, we attempted to mechanize the manual drilling (soft-machining) to establish a new drilling method with a small probability of burr generation. The thrust force in manual drilling is less than one-tenth of that in CNC machining. A total of more than 200 holes were drilled with the same drill at 35 to 110N of applied load. In the drilling of single plate, burr formation is related to the inclination of the drill exit surfaces. Even in the drilling of stacked plates, the soft-machining can drill the through holes at the specified points in all conditions. In the soft-machining, the level of load P[N] becomes an important parameter to minimize the damage generation and it may be a mandatory to adjust the load to the minimum level required for cutting and tool feed. Applying soft machining to robotic drilling may solve vibration problem.

Comparative study of drilling super austenitic stainless steel with external applications of reduced quantity nanofluid and flooded bio-lubricant

AISI 904L is a super austenitic stainless steel (SASS) with excellent corrosion resistance and good mechanical strength at high temperatures that can be applied in extreme operational conditions. Consequently, it has low machinability. Research involving SASS drilling is scarce in the literature. Thus, this work aims to evaluate the TiAlN-coated carbide drill life associated with thrust force and torque in the full-hole drilling of the Ultra® 904L under external lubrication with a 100-mm/min feed rate. Nanofluid-based reduced quantity lubricant (2.0 L/h) at 840-rpm spindle speed and flood bio-lubricant conditions (540 L/h) at 840- and 1260-rpm spindle speeds were applied, totaling three tool-life tests. Digital image analysis showed that the failures in the main cutting edges occurred due to chipping resulting from the rupture of the built-up edge. The drill wear did not reach expressive values. Low tool life was observed with nanofluid in reduced quantity (E1 test, 0.67 min) and flood condition with 1260 rpm (E3 test, 1.34 min). The longest drill life was registered for 840 rpm with flood biofluid (E2 test, 8.04 min). Lastly, a growth of 11% in thrust force and 9% in torque were noted when increasing the lubricooling flow from the E1 to E2 test; however, there was a reduction of 31% and 42% when raising the spindle speed from E2 to E3 test. The flood condition resulted in a longer drill life and smaller thrust force and torque values (at least 20% lower), which are associated with chip deformation, hardness, and friction coefficient reductions due to increased cutting speed and temperature. Moreover, built-up edges were formed during the drilling of all the holes.

High reliability model of mechanical response in drilling of CFRP/Al stacks

CFRP/Al laminate material is widely used in aerospace due to its advantages of light weight and high machinability. For assembling, crowded assembly holes need to be drilled for CFRP/Al laminate products. However, the damages of burr, delamination, and tearing appear frequently in drilling without precise guidance by mechanical response model. In order to reduce the machining damages, in this paper, a high-reliability mechanical response model is established for each stage in laminate materials drilling to ascertain the matching method between materials, tools, and cutting parameters. The theoretical expression of drilling thrust based on the thin plate theory is established considering the influence of cutting parameters, and further corrected with the cutting parameter correction terms to predict drilling thrust force, and further guiding the optimization of drilling parameters. According to the experimental results, the proposed model has a reliability greater than 97.3% and a prediction deviation lower than 13.2% in CFRP/Al laminate material drilling thrust force prediction. In the cutting with optimized parameters from the proposed model, the inlet orifice of the laminated material has no flanging burr, and the CFRP layer exit orifice has no defects as burr, delamination, or tearing.

Machinability analysis of delamination and thrust force in drilling of pure and added GFRP composites

The effects of cutting parameters on the thrust force and delamination factor in the drilling of pure, Al2O3, and SiO2 added GFRP/epoxy composites were investigated. Experimental studies were performed to investigate thrust force and delamination factor. Taguchi experimental design and response surface methodology were employed to establish parametric relationships between the experimental parameters and the machinability outputs consisting of delamination and thrust force. When examining the effect of cutting speed and feed on thrust forces and delamination factors for the three materials, the smallest values of the cutting parameters for all three materials gave the minimum thrust forces and delamination factors. Machinability Index is also proposed. According to the machinability index, under the effect of delamination and thrust force parameters, it was seen that pure epoxy composite material has better machinability than the other composite materials. It has been found that the effect of feed rate on delamination is greater than the cutting speed, and the cutting speed has a low effect.

Multi-objective optimisation of cutting parameters for drilling-induced damages and thrust force in AFRP drilling

Multi-objective optimisation of cutting parameters for drilling-induced damages and thrust force in AFRP drilling

Prediction model of chisel edge thrust force and material damage mechanism for interlaminar-direction drilling of UD-CFRP composite laminates

Interlaminar-direction drilling of carbon fiber reinforced plastic (CFRP) is a new machining mode different from the conventional drilling. The thrust force on chisel edge of interlaminar-direction drilling is a key factor for the machining quality of CFRP. Therefore, it is necessary to accurately predict the thrust force on chisel edge, and reveal the material damage mechanism for the study of CFRP interlaminar-direction drilling. In this work, the chisel edge of the conventional twist drill is divided into two parts: the cutting edge and the rake face. By respectively establishing the thrust force models of the cutting edge and the rake face, the prediction model of the thrust force of chisel edge for interlaminar-direction drilling of unidirectional CFRP (UD-CFRP) is established. The reliability of the prediction model is verified by the designed experiments. Moreover, the response law of the thrust force of chisel edge to the machining parameters is discussed in detail, and the material damage mechanisms under the action of chisel edge and main cutting edge are revealed by micro characterization of materials. This study is expected to enrich the theory of interlaminar-direction drilling of CFRP, and provide a theoretical basis for guiding the strategy about interlaminar-direction drilling of CFRP.

Analysis and prediction of woven fabric design impact on fabric/polymer composite drilling energy

Damage, generated during drilling processes, will affect the material integrity and further delamination through the fiber-reinforced composite cross-section. Drilling is necessary for the assembly processes of composite parts. This article deals with the effect of the weave parameters on the drilling mechanism. The mechanism of the yarn shearing ring drilling was investigated, and the quality of the drilled hole was carefully examined for different drilling conditions. Set up for measuring the power consumption during the drilling of different samples as well as the value of the thrust force was constructed. In the drilling of fabric-reinforced polymer composite, the torque, thrust force, and delamination factor are depending directly on fabric design parameters. It was shown that both, drilling power and drilling thrust force, are proportional to the total specific fabric stiffness. Delamination caused by drilling thrust is one of the most problematic defects after drilling laminate composite. A drilling Index was developed and could be used to evaluate the effect of the fabric design of laminate on its composite drilling performance. It was revealed that significantly higher drilling power is needed for the plain weave fabric design than for the other fabric designs of the same unit repeat as well as for the laminates of high fiber volume fraction and high total flexural rigidity. Analysis of the delamination factor and the drilling power showed a high correlation with total fabric flexural rigidity.

Optimization of Torque and Thrust Force for Drilling of the Spray-Deposited Al–16Si–15Pb Alloy

Optimization of Torque and Thrust Force for Drilling of the Spray-Deposited Al–16Si–15Pb Alloy

Rare earth metals recycling market worth $422 M by 2026

Edentulism is a condition that results in the partial or total loss of teeth. It may lead to problems during chewing and be a cause of self-isolation and low self-esteem. Edentulism can be resolved both with removable prostheses (dentures) and fixed implants, with the latter being more efficient. The installation of a fixed implant involves a real surgical operation in which the jaw/mandibular bone is drilled through a special drill. One of the main cautions the surgeon must have during the operation is not to sever the nerves during the drilling. Given the composition of the bone is different in each person, the drilling thrust force is variable and controlling its movement can sometimes be complicated. Therefore, being able to test the operation on a dummy may reduce the number of errors. Additive manufacturing with its high degree of customization and ability to produce objects with almost no geometrical limitations could provide the required features to realize the dummy. In this work, the drilling properties of samples made in PLA through Fused Filament Fabrication (FFF) were studied. The samples were designed to mimic the composition of the bone. Specifically, a thin, hard, and denser outer layer and a 25% internal filling were adopted. The samples were drilled with a dental drill properly connected to a collaborative robot.

Multi-Objective Optimization in Single-Shot Drilling of CFRP/Al Stacks Using Customized Twist Drill

In recent years, the use of CFRP with titanium and/or aluminum to form materials for stacking has gained popularity for aircraft construction. In practice, single-shot drilling is used to create perfectly aligned holes for the composite-metal stack. Usually, standard twist drills, which are commonly available from tool suppliers, are used for practical reasons. However, existing twist drill bits exhibit rapid wear upon the drilling of composite-metal stack layers in single shot, due to the widely contrasting properties of the composite-metal stack, which causes poor surface quality. The stringent quality requirements for aircraft component manufacturing demands frequent drill bit replacement and thus incurs additional costs, a concern still unresolved for aircraft component manufacturers. Owing to highly contrasting properties of a composite-metal stack, it is obvious that standard twist drill cannot fulfil the rigorous drilling requirements, as it is pushed to the limit for the fabrication of high-quality, defect-free holes. In this work, customised twist drills of a tungsten carbide (WC) material with different geometric features were specially fabricated and tested. Twenty drill bits with customised geometries of varying chisel edge angle (30–45°), primary clearance angle (6–8°), and point angle (130–140°) were fabricated. The stacked-up materials used in this study was CFRP and aluminum alloy 7075-T6 (Al7075-T6) with a total thickness of 3.587 mm. This study aims to investigate the effect of twist drill geometry on hole quality using drilling thrust force signature as indicator. All drilling experiments were performed at spindle speed of 2600 rev/min and feed rate of 0.05 mm/rev. Design of experiments utilising response surface methodology (RSM) method was used to construct the experimental array. Analysis of variance (ANOVA) was used to study the effect of parameters and their significance to the thrust force and thus the hole quality. The study shows that the most significant parameter affecting the drilling thrust force and hole surface roughness is primary clearance angle, followed by chisel edge angle. Correlation models of CFRP thrust force (Y1), Al7075-T6 thrust force (Y2), CFRP hole surface roughness (Y3), Al7075-T6 hole surface roughness (Y4) as a function of the tool geometry were established. The results indicated that the proposed correlation models could be used to predict the performance indicators within the limit of factors investigated. The optimum twist drill geometry was established at 45° of chisel edge angle, 7° of primary clearance angle, and 130° of point angle for the drilling of CFRP/Al7075-T6 stack material in a single-shot process. The error between the predicted and actual experiment values was between 6.64% and 8.17% for the optimum drill geometry. The results from this work contribute new knowledge to drilling thrust force signature and hole quality in the single-shot drilling of composite-metal stacks and, specifically, could be used as a practical guideline for the single-shot drilling of CFRP/Al7075-T6 stack for aircraft manufacturing.