Increase In Material Removal Rate Research Articles

Optimization of Cutting Parameters for Sustainable Machining of Titanium Ti-5553 Alloy using Genetic Algorithm

Titanium Ti-5553 alloys have been considered as difficult-to-machine materials due to the extremely high tool wear, high cutting forces, high temperature, and poor surface quality of machined parts. Process parameters needs to be optimized in order to improve machining performance and in the meantime reducing manufacturing cost. This study proposes sustainable machining process for this new generation Titanium Ti-5553 alloy. Process parameters including depth of cut, cutting speed, and feed rate were taken into account to optimize parameters for reducing tool wear, energy consumption, and surface roughness, and in the meantime increase material removal rate. Genetic algorithm was utilized for optimizing the process parameters. Obtained results illustrated that optimization using genetic algorithm is a very effective approach to substantially improve machining performance of this alloy and make machining process of this alloy more sustainable by reducing energy consumption, manufacturing cost and increasing material removal rate in machining process of new generation titanium alloy.

Experimental investigation of the effect of tool material on the performance of AISI 4140 steel in the rotary near dry electrical discharge machining

This research conducts in three sections. The first section studies the effect of tool materials and gases on rotary workpiece electrical discharge machining. During the experiments, the effects of three kinds of tool materials (Cu, Cu-Cr, and Cu-Sn) and three types of industrial gases (air, argon, and CO2) on the material removal rate, tool wear rate, and workpiece surface roughness are investigated. The second is a comparison between rotary workpiece, rotary tool, and the fixed workpiece by choosing the appropriate tool material and gas in order to observe the effect of workpieces rotation on the process. Finally, another comparison has been done between wet electrical discharge machining and near dry electrical discharge machining of the fixed workpiece in order to study the effect of the dielectric. The results show the copper tool has the best performance compared with other tools. Scanning electron microscopy output shows the Cu-Sn tool creates shallow micro-cracks on the surface. Air and CO2 gases have the higher material removal rate in low current, but argon has better function than other gases in high current. In addition, a rotational speed causes an increase in material removal rate and tool wear rate and surface roughness decrease in near dry electrical discharge machining. The level of tool wear rate has decreased by 14% in the rotary workpiece compared with the rotary tool.

Removal Mechanism of Titanium Alloy Material in Ultrasound Vibration Drilling

In drilling the ultra-slim small diameter deep hole of titanium alloy, the problem of chip breaking and chip removal is common. When the drill is working normally, the ultrasonic vibration can be applied for the drill bit to cut the bit in the vibration to form a pulse. The cutting force waveform in drilling, should select the reasonable vibration frequency, amplitude, feed amount, workpiece rotation and other parameters to match, control the size and shape of the chip, get satisfactory chips, and avoid chip clogging. In this study, the ANSYS finite element simulation software was used to simulate the TC4 drilling process, and the difference between ultrasonic vibration drilling and ordinary drilling was analyzed. Drilling experiments were carried out. The experimental results show that compared with conventional drilling, ultrasonic vibration drilling has better surface quality, reduced tool wear and increased material removal rate.

Model hybrid magnetorheological damping prediction in machine tools

Vibration is an unbalance effect generated at the tool-workpiece interface during mechanical machining operations. Vibration is one of the most significant problems encountered when increasing material removal rate. It may contribute to tool wear and reduced surface finishing of the workpiece, which is referred to as ‘chatter’. However, to date, there are no significant experimental and corresponding simulation data for easy control with monitoring of the damping system model available to estimate parameters of machining F1140 Steel and to develop adequate models of magnetorheological damper (MRD) vibration control. This research adopts a novel approach to active dampers for MRD, which is manipulated by a control strategy to increase the dynamic structural damping characteristics of machine tools without changing actual machining operations. The operation of the system is actualized by the adoption of shock absorbers and active command of an MRD, thereby increasing the vibration-free zone with an electromagnetic actuator to reduce or possibly eliminate chatter during machining operations. A novel smart tool holder (STH) for real-time sensor data collection was designed in MATLAB, which for monitoring purposes is located at the tip of the tool during operation. The selection of data includes self-developed vibration, frequency monitoring, system stability evaluation, and the runout time. One of the objectives of the STH is to enable the accurate determination of a numerical control metal cutting system in vibration reduction. It was further designed to increase stability and the cutting force that can be achieved with the actuator and can facilitate the use of different control strategies or filters.

Effect of chip load and spindle speed on cutting force of Hastelloy X

Research on cutting force revealed that the cutting force decreases as cutting speed increases, which is in line with Salomon’s Theory. However, the fundamental behaviour was never clearly explained because most studies had focused on increasing the cutting speed by increasing spindle speed without retaining the rate of chip load. On that note, the effect of increasing spindle speed while chip load is constant on the cutting force of Hastelloy X is presented in this paper. Third Wave AdvantEdge software was applied and half-immersion up-milling simulations were conducted in dry condition. Result showed that the resultant force was primarily affected by the axial force, followed by normal force and feed force. Trend-lines indicated that the behaviour of cutting force components and resultant force was quadratic. Desirability Function Analysis (DFA) results revealed that the optimum combination of chip load and spindle speed led to lowest cutting force components and resultant force was at 0.013 mm/tooth and 24,100 RPM. Furthermore, the optimum cutting conditions that led to the lowest cutting force components and resultant force at chip loads of 0.016 mm/tooth and 0.019 mm/tooth was 24,100 RPM also. Therefore, increasing Material Removal Rate (MRR) while minimizing cutting force components and resultant force can be achieved by increasing the amount of chip load at spindle speed of 24,100 RPM.

Modeling of plasma temperature distribution during micro-EDM for silicon single crystal

In silicon single crystal micro-electrical discharge machining (Micro-EDM), the plasma channel and workpiece temperature field directly affect the machined parts. For Si single crystal, with short single discharge time and small inter-electrode gap, the temperature cannot be easily measured directly. Based on the theory of energy conservation and heat conduction, combined with Micro-EDM process, in this paper, thermodynamic analysis of plasma in Micro-EDM process is conducted, and a plasma temperature distribution model considering latent heat of fusion is established. Adopting Gaussian distribution heat flux boundary condition and the temperature field distribution of the workpiece surface is simulated by FLUENT. The relationship between material removal rate (MRR) and surface roughness (SR) corresponding to temperature distribution under different peak current and pulse width conditions is analyzed. The results show that plasma temperature has a positive correlation with peak current and pulse width. The increase of peak current and pulse width within the processing parameter range leads to the increase of MRR and SR. The experimental results verify the correctness of the model.

Optimization of Process Parameters on CNC milling machine for Mild steel IS 2062:2011 E250 Gr. A with AlTiN coated tool insert in wet condition

Now a days manufacturing industries wants to increase the quality of product and reduce manufacturing cost. The aim of this project work is to reduction of energy consumption during the machining phase, reduce surface roughness and increase material removal rate by optimization of face milling process parameters of mild steed IS 2062:2011 E250 Gr A with Taguchi orthogonal array. 27 experimental runs based on L27 orthogonal array of Taguchi method were performed. Spindle speed, feed rate and depth of cut this process parameters are optimized with multiple performance characteristics such as surface roughness (Ra), Material removal rate (MRR) and power consumption. The machining operation performed on VMC by using coolant with 63 mm cutter diameter. The analysis of variance (ANOVA) is also applied to identify the most significant factor using Minitab software. The analysis can be done on AlTiN insert coating. At the last conformation test were performed.

Analysis of high aspect ratio small holes in rapid electrical discharge machining of superalloys using Taguchi and TOPSIS

The main aim of this paper is to perform high aspect ratio small holes using rapid electrical discharge machining (rapid-EDM) of superalloys, namely Ti–6Al–4V and Inconel 718 with the tool materials like brass tubes and copper tubes. For employing the above-said materials, the performance characteristics such as material removal rate (MRR), tool wear rate (TWR) and overcut (OC) have been studied. In these investigations, DOE-Taguchi’s L9 orthogonal array has been utilized to build an experimental layout with the machining parameters such as current, on-time, off-time and capacitance. From the analysis, it is confirmed that there was a 40% increase in MRR, 282% decrease in TWR and 56% decrease in OC for rapid-EDM of Ti–6Al–4V material using the brass tubes than the copper tubes. Further, it is also validated that there is a 61% increase in MRR, 6% drop of TWR and 33% increase in OC for rapid-EDM of Inconel 718 material using brass tubes than the copper tubes. So, this comparative study has concluded that the machining of Ti–6Al–4V using brass tube has produced a maximum of MRR and minimum of TWR and OC. In Taguchi analysis, the individual effect of machining parameters on MRR, TWR and OC was studied. In addition, optimum combinations of machining parameters for MRR, TWR and OC were also discussed. Furthermore, multi-objective optimization was executed using TOPSIS to find good combination of machining parameters.

Prediction model of machine tool energy consumption in hard-to-process materials turning

Accurate energy consumption prediction before actual turning is helpful for operators to select optimal processing parameters to improve energy efficiency. Tool wear is very fast in hard-to-process materials turning, which leads to the increase of cutting force, cutting temperature, and cutting power of machine tool. However, most existing prediction models do not consider the impact of tool wear on machine tool energy consumption. A new prediction model of machine tool energy consumption based on tool wear, spindle speed, and material removal rate in hard-to-process materials turning is developed, and verified with 06Cr19Ni10 stainless steel turning experiments. The experimental results show that the proposed model has higher prediction accuracy, and the maximum relative error between predicted value and true value is 2.9%. Furthermore, the influence of processing parameters and tool wear on machine tool energy consumption is studied. The machine tool energy consumption is proportional to the material removal volume, and linearly related to tool wear and spindle speed. The machine tool energy consumption decreases with the increase of material removal rate. The research results are helpful to formulate energy-saving turning scheme in hard-to-process materials turning.

Influence of Carbon based Fillers on EDM Machinability of CFRP

Machining of fibre reinforces plastics is inherently difficult due to the abrasiveness, inhomogeneity and anisotropic properties. Generally, tool wear rates are high, which results in high cutting forces and adverse surface quality. Additional damage such as delamination or matrix degradation, reduce the mechanical performance of the plastics. Hence, unconventional machining processes such as electrical discharge machining are of interest, as it does not induce large process forces and the associated drawbacks. The machinability of carbon fibre reinforced plastics using electrical discharge machining has been shown previously. The process has indicated problems such as the thermally damaged surface layer formation or unintentional degradation of the matrix material. Hence, the electrical discharge machining of carbon fibre reinforced plastics is only suitable in certain process parameter ranges.In this work, experiments on electrical discharge drilling of carbon fibre reinforced plastics were carried out. Different filler materials and various technological process parameters were investigated. Graphite and carbon black were added to the matrix to increase the electrical and thermal conductivity to study its influence on machinability, thermal damage and surface quality.The use of fillers has shown promising results regarding the elimination of thermal damage, increase of material removal rate and decrease in tool wear when electrical discharge drilling carbon fibre reinforced plastics.

Application of root cause analysis to increase material removal rate for productivity improvement: A case study of the press manufacturing industry

The bore machining of a large size cylindrical job on a lathe machine is a challenging job. Due to the large diameter of job or financial constraints, it is not always possible to use the steady rest. This results in the overhang of a job, which directly affects the material removal rate. This paper discusses the use of lean manufacturing in a press manufacturing industry to improve productivity through increased material removal rate of boring operation. A flange fixture is developed and it has reduced the machining time by 9.5 h.

Interactions of grinding tool and supplied fluid

This paper reviews the physical and chemical interactions between the rotating tool and the supplied fluid in grinding. The mechanisms of this tool-fluid interaction are the key for high performance grinding processes due to an efficient fluid supply resulting in a minimal thermomechanical impact on workpiece and tool. Reduced wear, increased surface finish, suitable subsurface properties of the machined material, increased material removal rates, and also energy efficiency can be achieved. In this context, the fluid supply towards the contact zone between tool and workpiece, the tool cleaning with high pressure cleaning nozzles as well as (tribo)-chemical phenomena between the abrasive layer and the supplied fluid are analysed and discussed. Finally, knowledge gaps are revealed which are indicating future research needs.

Fuzzy control of the dual-stage feeding system consisting of a piezoelectric actuator and a linear motor for electrical discharge machining

Gap width is an important factor that affects material removal rate, surface finish, and machining stability in electrical discharge machining processes. This research is to develop a novel control method for a new hybrid positioning system which consists of a linear motor and a piezoelectric actuator for high-efficiency electrical discharge machining processes. In the new system, the linear motor provides the macro feeding while the piezoelectric actuator feeds the workpiece in micro scale at high frequency. To reduce the delay caused by separate movements of the linear motor and piezoelectric actuator, a new control algorithm was developed to synchronize the movements of the motor and piezoelectric actuator. A fuzzy control system was used to control the feeding process. Piezoelectric actuator position and its speed were selected as the fuzzy inputs, while the fuzzy output was the linear motor speed. Cutting experiments were conducted, and results show that the fuzzy system is more powerful than the conventional algorithm and the new algorithm with constant motor speed. An increase in material removal rate of 1.6 times was achieved using the proposed fuzzy control algorithm.

Comparison on grindability and surface integrity in creep feed grinding of GH4169, K403, DZ408 and DD6 nickel-based superalloys

Comparative study was conducted on the grindability of wrought GH4169, equiaxial cast K403, directionally solidified cast DZ408 and single crystal DD6 superalloys by using the brown alumina wheels during the creep feed grinding process with regard to the grinding force, grinding ratio, wheel wear and surface integrity. The grinding forces were found to increase in the following order: DD6, GH4169, K403 and DZ408; and DD6 alloy had the largest grinding ratio, followed by GH4169, K403 and DZ408. In addition, the workpiece material adhesion and grain wear flats were found to be the main pattern of wheel wear in the grinding of DZ408, K403 and GH4169 alloys, while it was the wheel clogging for DD6 alloy. Irrespective of the workpiece material, the microhardness alternation of subsurface induced by thermal effect dominated over the mechanical effect with the increasing material removal rate (up to 6 mm3/(mm s)) and the softened level was 10–16.5 % to a depth of around 40 μm in this study. The surface defects, the highly deformed subsurface and the generation of micro cracks within the workpiece were found to be the main types of damage induced by the grinding operation. These results can provide insights into the effect of workpiece material on the grindability of different nickel-based superalloys in the investigation.

Machinability of high-speed enamel cutting with carbide bur

The cutting of tooth enamel using a high-speed air-turbine handpiece and carbide bur is a key procedure in oral surgeries, such as the minimally invasive extraction. However, presently little is known about the cutting mechanics and material removal mechanism related to tooth enamel machinability. In this study, the machinability of high-speed enamel cutting with carbide bur is studied by a computer-aided numerical control system. The dynamic cutting forces of enamel of the occlusal, buccal/lingual, and proximal surfaces were measured by the force measuring system. The force ratio, cutting torque, rotating speed, specific cutting energy, and bur wear were analyzed. The microstructure of enamel and carbide burs was observed by the scanning electron microscope, and the relationship between enamel microstructures and machinability was further analyzed. The results show that during the high-speed enamel cutting with carbide bur, the chip thickness is on the nano-scale, and the plastic deformation of the machined surface is obvious. With increased material removal rate, the cutting force, torque, specific cutting energy, and bur wear increases accordingly, whereas the rotating speed decelerates (p < 0.05). The different angles between the cutting direction and the axial direction of the enamel rods give rise to the large differences in the cutting mechanics and mechanism of the proximal, buccal/lingual, and occlusal surfaces of the teeth. When the cutting direction is parallel, vertical, and oblique 45° to the axial direction of the enamel rods, the force required for material fracture and crack propagation increases, and the cutting force increases as a consequence. Parallel and oblique 45° cutting are the main modes of tooth segmentation in the minimally invasive extraction. In comparison with the parallel cutting mode, the cutting force, torque, and cutting ratio of the oblique 45° cutting mode can be significantly increased, and the tool wear is obviously accelerated. This is the lowest priority in segmentation surgery, hence the problems of overload and temperature rise need to be considered. The cutting mechanics and cutting mechanism obtained in this study will provide scientific process guidance for dental cutting operations with the air-turbine handpiece driving bur.

Analysis of electrical discharge machining parameters for H13 steel using OVAT technique

Electrical discharge machining (EDM) is the most dominant innovation in the field of non-traditional machining for the processing of difficult-to-machine materials. This practice considerably improves the machining characteristics by increasing material removal rate, surface hardness together with the reduced surface roughness and tool wear rate. In the present study, one-variable-at-a-time (OVAT) approach was employed to investigate the input machining parameters for H13 steel with copper tool. The effectiveness of input parameters evaluated in terms of material removal rate (MRR), tool wear rate (TWR) and surface roughness (SR), opted as output responses. It was observed experimentally that discharge current 9 A, pulse-on duration 250 μs and spark gap voltage of 50 V notably influence the machining characteristics of H13 steel with copper tool.

Study on Effects of Low Frequency Vibration on Efficiency of Die Sinking Electrical Discharge Machining

The vibration integrated into die-sinking electrical discharge machining is a relatively new solution, so it has been creating the interest of researchers. In this paper, the authors studied the effect of low frequency vibration attached onto workpiece to efficiency of die- sinking electrical discharge machining. Copper electrode and SKD61 die steel were selected to investigate. Material removal rate, tool wear rate and surface roughness were quality indicators investigated in this study. Experimental results showed that the low frequency vibration has a positive effect on the efficiency of die-sinking electrical discharge machining. Comparing to die- sinking electrical discharge machining traditional, when the vibration unit is integrated onto work-piece in die-sinking electrical discharge machining, the largest increase of material removal rate was 34.94 %, the greatest reduction of tool wear rate was 16.0 % and the largest reduction of surface roughness was 26.36 % and profile of machined surface was better.

Enhancing the Tool Die Steel P rofile C utting P erformance in WEDM P rocess

This work elaborates the experimental work on Material Removal Rate (MRR) and Surface Roughness (SR) output conditions of Wire-Electrical Discharge Machining (WEDM) and finding the optimal input conditions through Taguchi method coupled with Grey relational analysis for lower SR and higher MRR during profile cutting of high strength D3 tool steel, which is the need of the hour in industries. The machining factors considered for investigation which influences MRR and SR were: cutting speed, pulse on-time and off-time, input current, wire tension and feed and servo feed and voltage. A L18 orthogonal array was considered for mixed-level experimental design through Taguchi’s approach and for multi-criteria optimization Grey Relational Analysis was applied. Outcome shows that SR increases with the increase of pulse on-time and decreases with increase in pulse off-time and MRR increases as the pulse on-time increases due to longer spark duration. Both SR and MRR are well within the control limits and servo voltage is the most influential parameter contributing by 48.48%, followed by wire feed rate, input current and servo feed rate with an R2 value of 95.85%, identified through Analysis of Variance (ANOVA). With obtained optimum conditions, a validation experiment was conducted to authenticate the results, which indicates a worthy agreement with predicted output characteristics.

Machining characteristics and mechanism of GO/SiO2 nanoslurries in fixed abrasive lapping

Abstract Water-based slurries with silica (SiO2) nanoparticles, graphene oxide (GO) nanosheets and GO/SiO2 hybrid nanostructures as abrasives were synthesised in order to achieve a high-efficiency and low-damage lapping. Tribological characteristics of SiO2, GO and GO/SiO2 nanoslurries were systematically investigated to optimise slurry formulae, and the lubricating mechanisms involved were revealed based on the analyses of worn surfaces and used slurries. Machining performance of the optimised slurries was then examined in the fixed abrasive lapping of glass substrates in terms of surface quality and material removal. The GO/SiO2 slurry of 0.16 wt.% at a mass ratio of 1:1 generated a lubricating layer consisting of C deposited and SiO2 dynamic films at the rubbing interface. This improved friction and wear conditions at the contact, producing a significantly lower COF and a better worn surface quality than those slurries containing only GO or SiO2. The lapping with the GO/SiO2 slurry thus reduced the surface damage on glass and achieved a crack-free subsurface. In comparison with a conventional lapping, the new lapping process resulted in a 35% reduction in surface roughness, but a 28% increase in material removal rate. Such improvements were attributed to the synergistic lubrication behaviour of the formed nanostructures of GO/SiO2 in water.

Optimization of the Electrical Discharge Machine using AZ 31 Magnesium alloy

Electrical Discharge Machine (EDM) is the process of designing the material and including complex structure using electrical discharge. Many research has been carried out in the EDM using different materials to increase Material Removal Rate (MRR), decrease Electrode Wear Rate (EWR) and Surface Roughness (SR). The various optimization techniques are applied to identify the parameter settings to increase MRR. In this research, the EDM process is conducted using the material of AZ 31 Magnesium alloy with hydrothermal treatment to reduce the MRR. The Taguchi method is applied to identify the optimal parameter for the EDM process to minimize the MRR, EWR and SR. The optimal value of the method is obtained as peak current of 55 A, voltage of 220 V, pulse on-time of 16 μs, and the pulse off-time of 512 μs.