Values Of Feed Rate Research Articles

Effect of Machining Parameters on the Surface Roughness of Medium Carbon Steel Using Lathe Machine

The service life of a machined part depends greatly on the quality of its surface roughness value. Depending on the requirements of the intended service life, machined parts may be smooth or rough. Therefore, the quality of surface finish of machined parts must be closely monitored by technicians, artisans and operators in the shop floor in order to achieve optimal output from machining operations. The quality of surface finish obtained through machining operations are affected by a number of factors. However, the most important factors are the cutting speed, feed rate and depth of cut. These are the parameters that directly affect the characteristics of the surface roughness value of a machined component. In this study, an investigation was carried out on the effect of machining parameters on the surface roughness of 0.3% medium carbon steel using the Lathe. All other factors inherent in the cutting operations was held as constant whilst the cutting parameters were intermittently varied. For each combination of cutting speed, feed rate and depth of cut, the corresponding value for surface roughness was measured and recorded. The methods of analyses chosen for this study were artificial neural network, response surface methodology and the factorial design. Findings from the study show that the result from artificial neural network and the factorial design method exhibited similar patterns with the results of previous studies which recorded that feed rate was the most significant parameter affecting surface roughness. Also, findings revealed that increasing feed rate, cutting speed and depth of cut would result in a corresponding increase in the surface roughness values. Results obtained through response surface methodology generally did not agree with most of the findings of previous works in literature. Based on the predictive capabilities of the three models, statistical metrics indicated that the ANN model was found to be the best model with a coefficient of determination of 0.9979 and a mean square error of 0.003017. This was followed by the factorial design model with a coefficient of determination of 0.9298 and a mean square error of 0.0980. The model from the response surface methodology came last with a coefficient of determination of 0.9600 and a MSE of 0.1008. From the findings, it is strongly recommended that values of feed rate must be systematically selected during machining operations and the models developed could be used to predict the surface roughness of 0.3% medium carbon steel by technicians and artisans on the shop floor.

PROPERTIES OF GRADIENT LAYERS OBTAINED THROUGH HVOF SPRAYING AND PLASMA CLADDING

The study discussed in the article aimed to identify the obtainability of a gradient layer made by the High-Velocity Oxygen Fuel (HVOF)-spraying of an NiAl-based coating between a layer made using the plasma cladding process and powder Stellite 6 and a substrate made of structural steel S355JR. Overlay welds obtained in related tests were made using various process parameters as well as various values of current, travel speeds and powder feed rates. The study also involved the performance of macro and microscopic metallographic tests, hardness measurements as well as the analysis of the chemical and phase composition of gradient layers.

Calculation of force parameters of workpiece machining process with end mill cutters

The aim is to develop and validate an operational methodology for calculating the force parameters and characteristics of the tool and the process of milling structural materials with end milling cutters. The structural schemes of machining and force models of oblique cutting processes in the modes of axial tool feed and continuous plastic deformation of the processed material were used when developing the method of preliminary calculation of the total axial force working on the cutting edge of end milling cutters. The rotating tool tests were conducted on a Hermle UWF 1202 H 3-axis machining center supplemented with a Kistler piezoelectric dynamometer (model 9272). Authors suggested, developed and tested the preliminary calculation method applied to the force characteristics of the machining process of workpieces by end milling cutters, considering how the energy power of ductile fracture of the machined material affects the process. Contact friction arising on the front and rear surfaces of the cutting tool does not reach the limiting value being subject to the Coulomb – Amonton law, that is, it is estimated by the dependence directly proportional to the normal pressure. After calculations, we defined the materials of the workpiece for milling, that is 45 steel (AISI 1045), and the end two-tooth cutter, uncoated T14K8 alloy, which was used to produce samples. The following milling modes were established: 4 mm boring depth; 50, 100 and 150 m/min cutting speeds; 0.05 and 0.1 mm/rev cutting tool feed. Deviation of the measured values of axial cutting force from the calculated values in the range of changing values of tool feed rate was found to be no more than 11%, and in the range of changing values of cutting speed no more than 15%. The developed calculation and analytical methodology for estimating force parameters of the machining process by end milling cutters provides an increase in the efficiency and reliability of the preliminary prognostic calculation of operating parameters and characteristics of cutting elements of end milling cutters.

ТЕОРЕТИЧЕСКОЕ И ЭКСПЕРИМЕНТАЛЬНОЕ ИССЛЕДОВАНИЕ ПРОИЗВОДИТЕЛЬНОСТИ ЗУБЧАТОГО БУНКЕРНОГО ЗАГРУЗОЧНО-ОРИЕНТИРУЮЩЕГО УСТРОЙСТВА ДЛЯ АСИММЕТРИЧНЫХ ДЕТАЛЕЙ ТЕЛ ВРАЩЕНИЯ

The article presents the results of a theoretical and experimental study of the performance of a mechanical disk gear hopper feeding-orienting device with an annular orientator for asymmetric parts of rotation bodies. For theoretical description of productivity, mathematical model of probability of gripping asymmetric parts with end face in form of truncated cone is presented, with the help of which it becomes possible to determine actual productivity of feeding-orienting device and estimate of influence on it of geometric parameters of parts, structural and kinematic parameters of hopper feeding-orienting device. Using the developed mathematical model, the parameters of the bunker feeding-orienting device were determined, at which its feed rate would be maximum. To confirm the adequacy and correctness of the developed mathematical model of capture probability to describe the feed rate, the results of experimental studies on the layout of the feeding device for two types of asymmetric parts with a truncated cone end are presented. Comparative analysis of the theoretical values of the actual feed rate of the feeding-oriented device with experimental ones showed their high convergence, which confirms the feasibility of using the proposed concept in assessing the feed rate of mechanical disk hopper feeding-oriented devices for asymmetric parts of rotation bodies.

Enhancing the single-track deposition quality of AISI 308L wire arc additive manufacturing via process optimization and cold forging treatment

Wire arc additive manufacturing (WAAM) has been established as a promising additive manufacturing technique for fabricating and repairing medium-to-large scale metallic engineering parts. However, achieving an excellent geometrical accuracy and high mechanical properties close to the parent metal require an optimal setting of parameters for every material system and, sometimes, post-processing treatment. In this work, WAAM of 308L stainless steel was performed, using gas metal arc welding as the heat source, at varying values of wire feed rate (WFR) and traverse speed (TS) to investigate its effects on the geometry, microstructure and mechanical properties of the deposited track. Thereafter, post-cold forging treatment was performed on the track deposited at the optimum parametric setting. The track width and height decreased with increasing TS due to reduction in the wire deposition volume per unit length of track. The track height increased as the WFR increased from 61.67 to 95 mm/s, after which the process became unstable, leading to a decline in height. The microstructure of the deposited track mainly comprised δ-ferrite and austenite phases while the hardness of the track deposits (ranging between 124–172 HV) was largely influenced by the presence of carbide precipitates and equiaxed grains size which reduced as the TS and WFR increased. The post-cold forging treatment resulted in strain hardening, which resulted in significant improvement in the track hardness (up to 219 HV) but a fall in its impact strength due to loss of ductility.

Influence of the feed rate value on the distribution of the Q‑factor along the cone of deformation of a CPR mil

To ensure the formation of the necessary microstructure of pipes made of titanium alloys of the Ti‑3Al‑2,5V type, when they are deformed at cold pilgrim rolling mills, it is necessary to provide certain deformation conditions. In particular, the deformation modes are distributed in such a way as to obtain the necessary Q‑factor distribution along the deformation cone. The purpose of this work is to determine the effect of the feed value on the Q‑factor distribution along the deformation zone during forward and reverse movements of the roll mill stand. 1Various methods of carrying out the CPT process were chosen in terms of feeding and rotating the workpiece during the double stroke of the roll mill stand. The research methods are based on known dependencies describing the effect of true deformations in the sections of the working cone on the Q‑factor in these control sections. Calibration using a mandrel with a curved shape of the working surface was chosen for the analysis. 1 Calculations were made for the case of feeding rate before the forward stroke, turning before the reverse, as well as for the case of feeding and turning in both positions of the roll mill stand. The case of mismatch of the feed size is considered, when the feed before the reverse stroke is larger than before the direct one. The methods of leveling the influence of pipe deformation features in the wall calibration zone on the formation of the necessary microstructure of pipes made of Ti‑3Al‑2.5V alloys are proposed.

Influence of Technological Parameters on Chip Formation and Chip Control in Precision Hard Turning of Ti-6Al-4V.

This article presents the results of an experimental investigation into the effect of process parameters in the precision hard turning of Ti-6Al-4V on chip morphology at both macro and micro levels. It also reports on the control of chip generation to improve chip evacuation and breakability at the macro level by varying the process parameters, namely, feed rate, cutting speed and depth of cut during turning tests. A scanning electron microscope (SEM) was used to examine the chips produced for a better understanding of chip curling mechanisms at the micro level. Surface roughness of the machined specimens was measured to assess the effect of chip evacuation on obtainable surface quality. From the results, it was found that the interaction of process parameters has a significant effect on the control of chip formation. In particular, the interaction of higher cutting speeds and greater depths of cut produced chip entanglement with the workpiece for all values of feed rates. Using relatively higher feed rates with a low depth of cut showed good results for chip breaking when machining at higher cutting speeds. Different chip curling mechanisms were identified from the SEM results. Chip side-curl formation showed different segmentation patterns with an approximately uniform chip thickness along the chip width, while chip up-curl occurred due to variations in chip thickness. Finally, it was found that the tangling of the chip with the workpiece has a significant effect on the final surface quality.

Exploring the Impact of the Turning of AISI 4340 Steel on Tool Wear, Surface Roughness, Sound Intensity, and Power Consumption under Dry, MQL, and Nano-MQL Conditions

Optimizing input parameters not only improves production efficiency and processing quality but also plays a crucial role in the development of green manufacturing engineering practices. The aim of the present study is to conduct a comparative evaluation of the cutting performance and machinability process during the turning of AISI 4340 steel under different cooling conditions. The study analyzes cutting operations during turning using dry, minimum quantity lubrication, and nano- minimum quantity lubrication. As control parameters in the experiments, three different cooling types, cutting speeds (100, 150, 200 m/min), and feed rate (0.1, 0.15, 0.20 mm/rev) levels were applied. The experimental results show that the optimal output values are found to be Vb = 0.15 mm, Ra = 0.81µm, 88.1 dB for sound intensity and I = 4.18 A for current. Moreover, variance analysis was performed to determine the effects of input parameters on response values. Under dry, minimum quantity lubrication, and nano-minimum quantity lubrication processing conditions, parameters affecting tool wear, surface roughness, current by the motor shaft, and sound level were examined in detail, along with the chip morphology. The responses obtained were optimized according to the Taguchi S/N method. As a result of optimization, it was concluded that the optimum values for cutting conditions were nano-minimum quantity lubrication cooling and V = 100 m/min, f = 0.1 mm/rev cutting. Finally, it was observed that there was a 13% improvement in tool wear, 7% in current, 9% in surface roughness, and 8% in sound intensity compared to the standard conditions. In conclusion, it was determined that nano-minimum quantity lubrication with the lowest level of cutting and feed rate values provided the optimum results.

EFFICIENT USE OF ELECTRIC ENERGY WHEN OPERATING A BALL MILL WITH A CONSTANT ROTATION SPEED

Link for citation: Zakamaldin A.A., Perevoshchikov F.V., Shilin A.A. Efficient use of electric energy when operating a ball mill with a constant rotation speed. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 115-127. In Rus. The relevance. Ball mills are widely used in industry for grinding bulk materials, as well as in the last stages of ore crushing, where the required optimal particle sizes are achieved for enrichment. Although ball mills have a relatively simple design and cover extensive research, the industry is still struggling with the very low energy efficiency of the grinding process. As the retrofitting heavy equipment is the costliest approach, process optimization through control system is the most suitable for energy consumption reduction. As a rule, the feed rate is the main control variable for a mill with a constant rotation speed. Due to insufficient information content, outdated methods of analysis and control of the internal dynamics of the mill, control systems keep the target value of feed rate at a deliberately low level in order not to overload the mill. This article provides an explanation of how, in such a case, an increase in mill feed rate could affect the energy efficiency of grinding. The main aim: study of energy efficient modes of operation of stations; verification of models and confirmation of experimental data: the relationship between door loading and power consumption indicators; construction of buildings for energy efficient control of ball towers. Objects: the process of grinding in a ball tower with a constant rotation speed. Methods: mathematical description of the behavior of the electromechanical part of a machine that consumes current and works on a load in the form of spherical furniture; simulation modeling of the operation of the door electric drive; statistical analysis of production indicators. Results. The paper demonstrate the tendency to increase electricity consumption with a decrease in feed rate and vice versa, respectively for ball mills with a synchronous drive of 2500 kW based on modeling and experimental data. Increase in feed rate in the range of 10–40 t/h, there is a drop in active power by 0,48–1,57 %. The values of the specific power consumption of ~5–8 kWh/t during the grinding of apatite ore were obtained. An increase in productivity by 5 t/h on average leads to a decrease in the specific power consumption by 0,12 kWh/t. It is necessary to increase productivity in the operation of ball mills only after integrating measuring instruments into the control system of the mill, which allow an accurate assessment of the state of loading of the mill drum.

Analysis of drilling behavior of flax/PP composites

ABSTRACT The current research investigation aims to use and compare three different population-based optimization approaches to optimize the operating factors of drilling process to reduce thrust force (TF) and subsequently delamination in flax/PP laminates. Five different tool point geometries and three levels of spindle speed (SS) and feed rate (FR) were considered. Analysis of variance indicated that drill point geometry was most significant parameter affecting the TF, whereas SS had the most negligible impact. Moreover, the lowest and maximum TF and delamination factor (DF) were recorded for the U-shape drill bit and 135°- point angle twist drill bit, respectively. The outcome of the experimental investigation revealed that a low FR value (0.05 mm/rev) and medium-range SS value (1500–1800 RPM) were optimum parameters for each drill geometry. Although all optimization techniques provided almost the same optimum values, but TLBO (teaching learning-based optimization) technique’s convergence rate was fast compared to others.

The Use of a Radial Basis Function Neural Network and Fuzzy Modelling in the Assessment of Surface Roughness in the MDF Milling Process.

Wood-based composites are increasingly used in the industry not only because of the shortage of solid wood, but above all because of the better properties, such as high strength and aesthetic appearance compared to wood. Medium-density fiberboard (MDF) is a wood-based composite that is widely used in the furniture industry. In this work, an attempt was made to predict the surface roughness of the machined MDF in the milling process based on acceleration signals from an industrial piezoelectric sensor installed in the cutting zone. The surface roughness parameter Sq was adopted for the evaluation and measurement of surface roughness. The surface roughness prediction was performed using a radial basis function (RBF) artificial neural network (ANN) and a Takagi-Sugeno--Kang (TSK) fuzzy model with subtractive clustering. In the research, as inputs to the ANNs and fuzzy model, the kinematic parameters of the cutting process and selected measures of the acceleration signal were adopted. At the output, the values of the surface roughness parameter Sq were obtained. The results of the experiments show that the surface roughness is influenced not only by the kinematic parameters of the cutting, but also by the vibrations generated during the milling process. Therefore, by combining information on the cutting kinematics parameters and vibration, the accuracy of the surface roughness prediction in the milling process of MDF can be improved. The use of TSK fuzzy modelling based on the subtractive clustering method for integrating the information from many acceleration signal measurements in the examined range of cutting conditions meant the surface roughness was predicted with high accuracy and high reliability. With the help of two tested artificial intelligence tools, it is possible to estimate the surface roughness of the workpiece with only a small error. When using a radial neural network, the root mean square error for estimating the value of the Sq parameter was 0.379 μm, while the estimation error based on fuzzy logic was 0.198 μm. The surface of the sample made with the cutting parameters vc = 76 m/min and vf = 1200 mm/min is characterized by a less concentrated distribution of ordinate densities, compared to the surface of the sample cut with lower feed rates but at the same cutting speed. The most concentrated distribution of ordinate density (for the cutting speed vc = 76 m/min) is characterized by the surface, where the feed rate value was vf = 200 mm/min, with 90% of the material concentrated in the profile height of 28.2 μm. When using an RBF neural network, the RMSE of estimating the value of the Sq parameter was 0.379 μm, while the estimation error based on fuzzy logic was 0.198 μm.

Optimization of surface roughness parameters in Hybrid-Chemo Magnetorheological Finishing (HC-MRF) process using Response Surface Methodology and Genetic Algorithm

Hybrid Chemo-Magnetorheological Finishing ( HC-MRF) process is an advanced surface finishing process that utilizes the interaction of Magnetorheological Finishing and chemical etching to reduce the surface roughness of the cemented carbide cutting tools. Herein, Murakami’s reagent is used as a Magnetorheological (MR) fluid carrier medium to trigger chemical etching and mechanical abrasion. The synergic action reduces surface finishing time and increases process efficiency. However, optimizing process parameters during the HC-MRF process is required to improve process efficiency further. Response Surface Methodology ( RSM) is used to develop the regression model to study the impact of process parameters (i.e. spindle speed, feed rate, and vol.% of Murakami’s reagent in MR fluid) on the surface quality. Three surface roughness parameters, namely average surface roughness ( Ra), skewness ( Rsk), and kurtosis ( Rk), are opted to analyze the surface characteristics of the polished surface. Furthermore, optimization is performed with the help of a Genetic Algorithm ( GA) to achieve the best surface quality following input parameters. The surface roughness ( Ra) is reduced by 88.97% as the initial Ra value decreases to 34.50 nm from 312.87 nm after the HC-MRF process. The results obtained from RSM and GA are in good agreement with the experimental results. The optimum value of feed rate, spindle speed, and vol.% of Murakami’s reagent in the MR fluid while achieving minimum surface roughness value (i.e. 31.26 nm) through GA are 1.2 mm/min, 23 rpm, and 53%, respectively. The measured kurtosis ( Rku) value of 0.64 at the optimum process parameter condition represents flat peaks on the surface roughness irregularities of the polished surface. Similarly, a skewness ( Rsk) value of 1.46 signifies that the number of peaks is higher than the number of valleys on the polished surface. Furthermore, it is observed that the Vol.% of Murakami’s reagent in MR fluid is the most significant process parameter compared with other parameters among all responses.

An effective approach for non-singular trajectory generation of a 5-DOF hybrid machining robot

By taking a newly developed 5-DOF (degree of freedom) hybrid robot as an exemplar, this paper presents a novel and effective approach for non-singular tool trajectory generation. Based upon singularity analysis via inverse kinematics, an algorithm for the C-axis path optimization is developed using the weighted S-curve. Incorporated singular domain detection with the C-axis angle correction, the algorithm can easily be programmed and embedded into the CNC (computer numerical control) system as a postprocessing module and works in real-time. Then, an offline feedrate scheduling method is proposed by considering the drive and geometric accuracy constraints, allowing the rapid yet smooth movement in the neighborhood of singularity to be achieved. Additionally, it is found that the orientation accuracy can be improved by setting adequate cone angle and feedrate value. The results of both simulations and experiments on a prototype machine show that the C-axis can follow the non-singular tool trajectory well with relatively high rotary speed to pass through the singular domain, thereby verifying the effectiveness of the proposed approach.

Direct Energy Depositions of a 17-4 PH Stainless Steel: Geometrical and Microstructural Characterizations

Direct energy deposition (DED) is a widely accepted additive manufacturing process and a possible alternative to the subtractive manufacturing processes due to its high flexibility in fabricating new 3D parts. DED enables the manufacture of complex parts without using costly and time-consuming conventional processes, even though building parameters need to be accurately determined. In the present investigation, the effect of different process parameters on geometrical features, quality, microstructure, and microhardness of 17-4 PH stainless steel single tracks deposited onto an AISI 316L stainless steel substrate was investigated. Four sets of process parameters, considering different values of laser power, scanning speed, and powder feed rate, were selected in the manufacturing strategy, and specimens drawn from each single-track deposition were analyzed by stereomicroscopy, optical microscopy (OM), scanning electron microscopy (SEM-EDS), and X-ray diffraction (XRD). The results show that the optimized geometrical features of the track, together with the best microstructural and hardness properties, were obtained with the highest values of the laser energy input.

A systematic survey of RUM process parameter optimization and their influence on part characteristics of nickel 718

This research is focused on the drilling of Nickel based super alloy with diamond metal core drill and identified the significant parameters of rotary ultrasonic machining that optimise the machining rate (MR) and surface quality. Four general parameters: workpiece material, workpiece thickness, tool material, and tool size; and four RUM parameters: tool rotational, feed rate, ultrasonic power rating, and abrasive grit size of the tool were tested against and surface quality of the cut. The results indicated that the maximum value of MR of 0.8931mm3/sec is acquired at higher level of tool rotation, feed rate, ultrasonic power and moderate level of abrasive grit size of diamond. The minimum surface roughness (Ra) 0.554 µm is observed at higher level of rotational rotation, Moderate value of feed rate, ultrasonic power and diamond abrasive grit size. In addition, for single-objective and multi-objective functions, the particle swarm optimization (PSO) approach is used to find the optimum values for process parameters. Furthermore, a scanning electron microscope is also utilized to check the machined surface after RUM. It is concluded that microcracks are observed on the machined surface.

Finite difference numerical modeling and experimental validation of workpiece surface temperature in micro-grinding

The objective of this work is to characterize the heat transfer and temperature generation into the workpiece during micro-slot grinding. A numerical model for predicting micro-grinding temperature is established based on the finite difference method (FDM). Workpiece volume is divided into small elementary sections and temperature in small sections near and away from the machining zone is calculated using thermo-physical model as well as validated by experimentally measured temperature using infrared technique. Temperature in micro-slot grinding increases during vertical insertion of the tool and becomes stable when the tool transverse in the feed direction. Simulation results show that transient heat transfer becomes dominant on increased feed rate values that result in an overall lowering of heat supply into the surface. Results also reveal that modification in the tool design has a significant impact on the reduction of workpiece temperature due to reduced contact length, reduced cutting forces, friction, and rubbing at the tool-workpiece interface. The proposed model is capable of solving transient problems in micro-slot grinding and is flexible to deal with different boundary conditions. This analysis will help in temperature prediction and establishing temperature reduction strategies that could potentially increase machining precision.

Control strategies for atmospheric pressure plasma polymerization of fluorinated silane thin films with antiadhesive properties

AbstractFinding proper strategies to control plasma polymerization processes is a crucial aspect to produce thin films with tailored characteristics. In this work, the validity of the Yasuda parameter W/FM (W: discharge power and FM: precursor feed rate) as a controlling parameter for a polymerization process assisted by an atmospheric pressure single electrode plasma jet and the aerosolized fluorinated silane precursor trimethoxy(3,3,3‐trifluoropropyl)silane is demonstrated. The properties of thin films deposited under different W/FM values are discussed using attenuated total reflectance—Fourier transform infrared (ATR‐FTIR) spectroscopy, X‐ray photoelectron spectroscopy (XPS), water contact angle (WCA) measurements, and scanning electron microscopy (SEM). Results suggest the presence of two deposition domains as a function of W/FM (an energy‐deficient domain and a monomer‐deficient domain), each inducing coatings with different chemical and physical properties. Furthermore, coatings deposited under the same W/FM values exhibit similar characteristics regardless of the power and feed rate values adopted. Considering the potential use of the deposited coatings to increase the antiadhesive properties of implantable medical devices, preliminary results on coatings' antiadhesive activity against Pseudomonas aeruginosa and Staphylococcus aureus are presented.

Statistical Analysis of Surface Roughness, Burr Formation and Tool Wear in High Speed Micro Milling of Inconel 600 Alloy under Cryogenic, Wet and Dry Conditions.

Super alloys offer excellent mechanical and chemical properties at elevated temperatures that make them an attractive choice for aerospace, automotive and chemical processing, and marine applications. These alloys are, however, difficult to machine due to their high strength at elevated temperatures, low thermal conductivity and work hardening. In this study, micro milling of Inconel 600 super alloy has been carried out and the effects of the key input parameters (cutting speed, feed rate, depth of cut) on response parameters (burr formation, surface roughness and tool wear), under various cooling conditions (dry, wet and cryogenic), have been analyzed. High speed micro milling (range up to 80,000 RPM) was carried out, while keeping the feed rate values below and above the cutting edge radius. The Taguchi design of experiments was used during this study. The results have been analyzed using SEM and 3D optical microscopy. Analysis of Variance (ANOVA) revealed that the best surface roughness values can be achieved under cryogenic machining condition with an overall contribution ratio of 28.69%. It was also revealed that cryogenic cooling resulted in the highest tool life with the contribution ratio of cooling conditions at 26.52%.

Effectiveness of hybrid Al2O3-TiO2 nano cutting fluids application in CNC turning process

The purpose of this study is to evaluate the effectiveness of hybrid Al2O3-TiO2 nano-cutting fluid in the turning process application under the selected significant machining parameters consisting of nano concentration, depth of cut and feed rate. The preparation of aqueous hybrid Al2O3-TiO2 water-based nano-cutting fluids and their application as the cutting fluid in turning operations are undertaken. The Al2O3-TiO2 hybrid nano-cutting fluids were prepared through a one-step method; by dispersing nanoparticles of Al2O3 (average diameter 30 nm) and TiO2 (average diameter 30-50 nm) in CNC coolant based at four different volume concentrations (1%, 2%, 3%, 4%). The effectiveness of turning cutting performance, namely cutting temperature (°C), average surface roughness (Ra), and tool wear (%), were assessed via air-assisted nano cutting fluids impinged through MQL setup in turning of Aluminium Alloy AA7075. The response surface method (RSM) was employed in the design of the experiment (DOE). The lowest cutting temperature, surface roughness, and tool wear of 25.8°C, 0.494 µm, and 0.0107%, are obtained, respectively, when the combinations of hybrid nano cutting fluid concentration of 4%, feed rate value of 0.1 mm/rev, and 0.3 mm depth of cut is used. The result in this paper is based on the experimental study of Al2O3-TiO2 hybrid nano-cutting fluid using CNC turning operation. The process focuses on the finishing process by using a finishing insert. Further work using roughing process may be suggested to observe the better performance of this cutting process using nano-cutting fluid towards reducing the wear rate. The use of Al2O3-TiO2 hybrid nano-cutting fluid coupled with MQL in the CNC turning process is considered a new method. Machining soft and delicate materials such as Aluminium should consider using this combination technique since it lowers the cutting temperature and removes the chips, reducing the adhesive wear. The hybrid nano-cutting fluid can replace the conventional cutting fluid and will perform better if combined with the MQL cooling technique; this new method should be considered by major industry players that require a high-precision finished product such as the product that involves aircraft and aerospace applications.

Mechanical Properties Enhancement of Dissimilar AA6061-T6 and AA7075-T651 Friction Stir Welds Coupled with Deep Rolling Process.

The main purpose of this research was to enhance the mechanical properties of friction stir welds (FSW) in the dissimilar aluminum alloys 6061-T6 and 7075-T651. The welded workpiece has tensile residual stress due to the influence of the thermal conductivity of dissimilar materials, resulting in crack initiation and less fatigue strength. The experiment started from the FSW process using the 2k full factorial with the response surface methodology (RSM) and central composite design (CCD) to investigate three factors. The experiment found that the optimal rotation speed and feed rate values were 979 and 65 mm/min, respectively. Then, the post-weld heat treatment process (PWHT) was applied. Following this, the 2k full factorial was used to investigate four factors involved in the deep rolling process (DR). The experiment found that the optimal deep rolling pressure and deep rolling offset values were 300 bar and 0.2 mm, respectively. Moreover, mechanical property testing was performed with a sequence of four design types of workpieces: FSW, FSW-PWHT, FSW-DR, and FSW-PWHT-DR. It was found that the FSW-PWHT-DR workpiece had an increase in tensile strength of up to 26.29% and increase in fatigue life of up to 129.47% when compared with the FSW workpieces, as well as a maximum compressive residual stress of −414 MPa.