Improve Machining Performance Research Articles

The effect of the tractor driving system on its performance and fuel consumption

Improving machine performance and optimum energy usage are great importance in mechanized agriculture. The purpose of the study was to assess the tractor driving system including rear-wheel drive (RWD), four-wheel drive (4WD) and front-wheel drive (FWD) effect on the tractor performance and its fuel use during tillage operation. Then the field experiments were conducted to investigate the effect of driving system type. Moreover the tire inflation pressure of 170, 200, and 230 kPa, ballast weights of 0, 60, and 120 kg, and pulling force of 2, 6, and 10 kN on the Goldoni tractor performance were examined. The results indicated that the 4WD system had more impact on the rolling resistance than other factors. The trend of draft force represented that using the 4WD system allows achieving a higher pulling force without exceeding the allowable slip. In comparison, the FWD and RWD systems exceeded the allowable slip of the 6–10 kN draft force. At a pulling force of 2 kN, the minimum fuel consumption was corresponded to the RWD system while the maximum fuel consumption corresponded to the 4WD system. But in the pulling force of 10 kN, the situation was different and the type of driving system had a significant effect on reducing fuel consumption and the minimum fuel consumption was achieved for the 4WD system.

Improved YM Laser Machine Performance with Overall Equipment Effectiveness and Fault Tree Analysis Methods Implementation at PT. XYZ

In the development of the shoe-making industry, demanding companies continue to improve the quality and quality of production. PT. XYZ responded by improving the performance of the YM Laser machine which is the main engine in the sports shoe production line. The approach is carried out using the entire Equipment Effectiveness Method and Error Tree Analysis. The purpose of this study is to measure the ratio of value availability, performance ratio, quality ratio, total value of OEE on YM Laser machines, identify the root causes of problems and make improvement plans to improve machine performance. YM Laser Machines have a Overall Average Equipment Effectiveness Value of 75.89%. After researching with the OEE method, it was found that the root of the problem was to reduce speed. Furthermore, the investigation using a cause and effect diagram, obtained the main cause is a machine factor. All problems found were solved using Fault Tree Analysis on engine factors and their improvement efforts to make standard lens replacement so that the lens is always in optimal condition, changing the quality of the switch so that it is not easily damaged again, and regularly updating software and replacing standard bolts.

Modeling and performance evaluation of Al2O3, MoS2 and graphite nanoparticle-assisted MQL in turning titanium alloy: an intelligent approach

Recently, the urgency of improved machining performance and environmental sustainability has forced the manufacturer to seek for alternative cooling and lubricating agent/technique such as nano-fluid (NF)-assisted minimum quantity lubrication (MQL). In this context, the performances of aluminum oxide (Al2O3), molybdenum disulfide (MoS2) and graphite (C) NF-impinged MQL in turning of Ti alloy (grade II) using CBN tool were evaluated regarding the cutting force, cutting temperature and surface roughness. The cutting speed, feed rate, approaching angle and cutting conditions (i.e., NFs) were oriented following the Box–Behnken design-of-experiment. The experimental results showed that the graphite NF, compared to Al2O3 and MoS2, revealed the lowest cutting force, temperature and roughness. Moreover, it is evident from SEM images that graphite NF revealed a smoother machined surface and tool profile. This smooth tool and workpiece surface profile can be accredited to graphite’s role as a nano-lubricant and its breaking ability into smaller NFs under pressure. To make the study complete, the adaptive neuro-fuzzy inference system (ANFIS) was employed to predict, the response surface methodology (RSM) was used to mathematically model, and the composite desirability approach (CDA) was used to optimize the responses. A good agreement between the experimental and modeled observations was found; however, the ANFIS outperformed the RSM. Moreover, the analysis of variance exhibited that the cutting force and temperature were primarily influenced by the cutting speed and the surface roughness was afflicted mostly by the feed.

Simultaneous geometric error identification of rotary axis and tool setting in an ultra-precision 5-axis machine tool using on-machine measurement

This paper presents a method to identify the position independent geometric errors of rotary axis and tool setting simultaneously using on-machine measurement. Reducing geometric errors of an ultra-precision five-axis machine tool is a key to improve machining accuracy. Five-axis machines are more complicated and less rigid than three axis machine tools, which leads to inevitable geometric errors of the rotary axis. Position deviation in the process of installing a tool on the rotary axis magnifies the machining error. Moreover, an ultra-precision machine tool, which is capable of machining part within sub-micrometer accuracy, is relatively more sensitive to the errors than a conventional machine tool. To improve machining performance, the error components must be identified and compensated. While previous approaches have only measured and identified the geometric errors on the rotary axis without considering errors induced in tool setting, this study identifies the geometric errors of the rotary axis and tool setting. The error components are calculated from a geometric error model. The model presents the error components in a function of tool position and angle of the rotary axis. An approach using on-machine measurement is proposed to measure the tool position in the range of 10 s nm. Simulation is conducted to check the sensitivity of the method to noise. The model is validated through experiments. Uncertainty analysis is also presented to validate the confidence of the error identification.

The effects of elliptical ultrasonic vibration in surface machining of CFRP composites using rotary ultrasonic machining

Compared with conventional surface grinding (CSG) process, surface machining of carbon fiber-reinforced plastic (CFRP) composites using rotary ultrasonic machining (RUM) with vertical ultrasonic vibration generates smaller cutting forces because of improved machining performance and more damages to the machined CFRP surface due to the intermittent knocking induced by vertical ultrasonic vibration. It is reported that surface quality can be improved when the ultrasonic vibration is parallel to the feeding direction. In addition, elliptical ultrasonic vibration can be formed by the combination of horizontal and vertical ultrasonic vibrations. However, the effects of elliptical ultrasonic vibration in RUM surface machining of CFRPs are still unknown. This paper will study the influences of elliptical ultrasonic vibration on the machining performance and machined surface quality in RUM surface machining of CFRPs. The comparisons of output variables (including cutting forces, surface roughness, and machined surface topography) between RUM surface machining with elliptical ultrasonic vibration and the CSG process as well as RUM surface machining with vertical ultrasonic vibration will be conducted under different levels of input variables (including depth of cut, feedrate, and tool rotation speed). The abrasive-grain trajectory and the tool-workpiece contacting modes in these three machining processes are analyzed. It is found that RUM surface machining with elliptical ultrasonic vibration produced smallest feeding-direction cutting force, smallest vertical-direction cutting force, best morphology of machined surface, and smallest surface roughness among these three kinds of machining processes.

Micro EDM aided by ultrasonic vibration in nitrogen plasma jet and mist

Dielectric (e.g., kerosene-based oil, deionized water, air) is an essential part of electrical discharge machining (EDM), insulating the workpiece and the electrode and removing the gaseous bubbles and debris. In this paper, ultrasonic vibration (USV) and mist are added to micro-EDM in nitrogen plasma jet (NPJ) to improve machining performance. Water contact angle on the workpiece surface becomes very small due to increased hydrophilicity of the NPJ-treated surface. Experimental results indicate that the discharge distance is about 3.5 times of that without adding mist. Compared to results in NPJ under the same conditions, the material removal rate (MRR) has increased by four when aided with mist and increased more than six times further when aided with USV. Meanwhile, the surface roughness increased. In addition, the tool electrode wear rate (TWR) in NPJ and mist significantly decreased, especially, aided by USV. 3D micro feature has been generated in Brass successfully by the proposed method, and the TWR (-0.04%) is near zero.

Applicability of DLC and WC/C low friction coatings on Al2O3/TiCN mixed ceramic cutting tools for dry machining of hardened 52100 steel

The present work examines the applicability of DLC and WC/C low friction coatings on Al2O3/TiCN based mixed ceramic cutting tools for the dry and hard turning of AISI 52100 steel (62 HRC). The characterization of coated tools reveals that the coatings retain very low values of surface roughness, whereas the DLC coating exhibits much higher microhardness when compared to the WC/C coating. On the other hand, the WC/C coating exhibit a coarse surface morphology virtually due to the tungsten doping. Later, continuous turning tests were executed with the help of coated and uncoated cutting tools under dry cutting conditions, and their performance was investigated in terms of machining forces, cutting temperature and tool wear. Coating delamination by flaking and peeling is quite prominent in the case of both the coatings; however, it is less severe for the WC/C coated tool. The coatings help to reduce machining forces, cutting temperatures and tool wear, but the performance of coated tools converge towards uncoated tool as the cutting speed, and feed rate is increased. Both the coatings prevent the development of cracks near the cutting edge with WC/C coating exhibiting superior wear behavior basically due to its multilayered structure and better thermal stability. Moreover, the tested low friction coatings don't serve as thermal barriers and only the lubrication generated due to graphitization at the chip-tool interface is mostly responsible for the improved machining performance.

Machinability analysis and characterization of aluminium hybrid metal matrix composite using WEDM

The aluminium composites are being used for various number of applications like automobiles, aerospace, marine, construction, etc. Manufacturing industries keenly focus on improving their product quality by means of strength with reduction in cost. The hybrid metal matrix composites paved way for achieving those objectives through reinforcement of existing traditional materials. This work is also a novel approach of examining the suitability of aluminium alloy for aerospace and automobile application, by reinforcing with various proportions of Silicon Carbide (SiC) and Graphite (Gr). 5, 10 & 15% of SiC in combination with graphite of 1 & 2% by weight basis. Further the casted composite was explored for its machinability in Wire cut electrical discharge machining (WEDM) process. Voltage and current are the two control parameters chosen for the study with responses material removal rate and Kerf. The MRR is proportional to the production time and Kerf is proportional to dimensional accuracy. A hybrid Taguchi-GRA optimization technique was utilized for identifying optimal parameters for achieving the objective functions. Improved machining performance was shown by the composite containing 15% SiC and 1% Gr over the operating range of 65V and 3A in WEDM process. Finally, the optimized values were justified by using SEM imaging. The agglomeration occurs at 15% SiC addition to base aluminium metal.

Effects of tool rotation and powder abrasive on EDM performance of H13 tool steel

The present work reports an experimental study on the performance of rotary electro-discharge machining (REDM) on H13 tool steel using rotary copper electrode in the presence of abrasives. Machining performance was evaluated in terms of machining rate and surface roughness. Experiments were conducted with peak current, speed of electrode rotation, concentration of abrasive and pulse on time as process variables. Taguchi methodology was adopted for experimental design. Analysis of variance (ANOVA) was performed to investigate the influence of input parameters on material removal rate (MRR) and surface roughness (SR). This work introduces a new method abrasive mixed REDM of improving machining performance vis. rotation of tool in presence of abrasives. Results indicated that giving rotation to EDM tool results in considerable improvement in MRR and SR. This method successfully removed the debris from the machining area which was one of the major challenges in the existing process and major cause of rough surface due to inactive pulses. It was confirmed experimentally that material removal rate increased by 25.53% and surface roughness decreased by 21.22%.

Effects of tool rotation and powder abrasive on EDM performance of H13 tool steel

The present work reports an experimental study on the performance of rotary electro-discharge machining (REDM) on H13 tool steel using rotary copper electrode in the presence of abrasives. Machining performance was evaluated in terms of machining rate and surface roughness. Experiments were conducted with peak current, speed of electrode rotation, concentration of abrasive and pulse on time as process variables. Taguchi methodology was adopted for experimental design. Analysis of variance (ANOVA) was performed to investigate the influence of input parameters on material removal rate (MRR) and surface roughness (SR). This work introduces a new method abrasive mixed REDM of improving machining performance vis. rotation of tool in presence of abrasives. Results indicated that giving rotation to EDM tool results in considerable improvement in MRR and SR. This method successfully removed the debris from the machining area which was one of the major challenges in the existing process and major cause of rough surface due to inactive pulses. It was confirmed experimentally that material removal rate increased by 25.53% and surface roughness decreased by 21.22%.

Effects of the Tribological Behaviour of h-BN MQL Nano Cutting Fluid (NCF-MQL) on Turning Inconel 625

Minimum quantity lubrication (MQL) is currently a widely used lubricating technique during machining, in which minimum amount of lubricant in the form of mist is delivered to the machining interface, thus helps to reduce the negative effects caused to the environment and human health. Further, to enhance the productivity of machining process specifically for hard-to-cut materials, nano cutting fluid (suitably mixed nano materials with conventional cutting fluid) is used as an alternative method to conventional lubrication (wet) in MQL. In this study, h-BN nano cutting fluid was formulated with 0.1% vol. concentration of h-BN in conventional cutting fluid (Servo- ‘S’) for NCF-MQL technique and its tribological behaviors on machining(turning) performance of Inconel 625 were studied and compared with other lubricating conditions (dry, wet, MQL conventional). The tribological effects were analyzed in terms of tool wear analysis, chip morphology along with statistical analysis for machined surface and evolved cutting forces during machining. The optimal input machining parameters for experiments were defined by the use of Taguchi and Grey relational based multi response optimization technique. Finally, the tribological study shows that the use of h-BN NCF-MQL is a viable and sustainable option for improving machining performance of hard- to- cut material like Inconel 625.

Investigation on machining characteristics of TC4 alloy by simultaneous application of ultrasonic vibration assisted milling (UVAM) and economical-environmental MQL technology

Abstract The optimization of machining methods is one of important guiding principles for achieving high-quality, cost saving and environmental protection machining of difficult-to-machine materials in modern manufacturing. Considering the principles and advantages of ultrasonic machining (UM) method and minimum quantity lubrication (MQL) technique, the simultaneous application of UM and MQL methods is anticipated to further improve machining performance in terms of cutting force, surface quality and chip morphology. Theoretical analysis indicates that the MQL system in UVAM could provide enhanced lubrication and cooling performance because of the separate-type cutting mechanism, the surface acoustic and the cavitation phenomenon of resonant workpiece in UM. Conventional milling (CM) trials, general UVAM trials and combined UVAM&MQL trials were conducted to investigate the effect of UVAM and MQL methods on machining performance of TC4 alloy, where the results of CM and general UVAM could provide indispensable reference. Multifaceted comparisons are presented in machining results of CM, UVAM and UVAM&MQL trials in terms of time-domain analysis and frequency-domain analysis of milling force, average cutting force, surface topography, surface profile and surface roughness. The results show that cutting force features could be significantly affected under UVAM and UVAM&MQL condition compared with that in general milling due to intermittent cutting mechanism and the coupling effect of UVAM and MQL methods. The uniform micro-textured surfaces with improved profile fluctuations could be obtained when applying the UVAM&MQL strategy. Compared with surface roughness in CM and UVAM, the surface roughness in UVAM&MQL is improved by about 30–50% and about 20–30%, respectively. The excellent machining performance demonstrates the feasibility and effectiveness of simultaneously applying UVAM and MQL methods.

An assessment for a new approach to pulsating lubrication strategy (PLS) in end milling

This paper presents the result of pulsating lubrication strategy (PLS), an alternative metalworking fluids approach to improve machining performance. The formation of built-up edge (BUE) and built-up layer (BUL) is among the problems encountered during the machining of aluminum alloy, which degrades cutting performance and thus affects the machined surface quality. This study focuses on chip removal effectiveness by jetting a coolant intermittently of PLS on the cutting tool to create a hydraulic shock. The water stream coolant was set to pulsate at 2000 pulse/min with the pressure of 0.76 MPa. Applying this method improves chip evacuation. Hence, minimizing the formation of BUE and BUL more effectively than dry cutting.

Estimation of Energy Savings When Adopting Ultrasonic Vibration-Assisted Magnetic Compound Fluid Polishing

Reducing energy use is a major consideration in green manufacturing. Ultrasonic vibration has the advantage of improving machining performance. This work presents an experimental investigation on magnetic compound fluid (MCF) polishing with and without ultrasonic vibration and estimates reductions in polishing energy consumption and surface roughness due to ultrasonic vibration during the machining process. A series of ultrasonic vibration-assisted MCF polishing (UVAMP) tests was carried out for brass H62, and the normal and tangential polishing forces, surface roughness and material removal rate of the traditional MCF polishing (MP) and UVAMP of brass were investigated for various machining parameters. The polishing energy consumptions during traditional MCF polishing and UVAMP were calculated and analyzed from the perspective of the energy of the polishing process. Results indicate that the use of UVAMP considerably reduces energy consumption and surface roughness during the polishing of brass. The adoption of UVAMP therefore has the potential to improve the efficiency and quality of polishing processes and offers a practical solution for the greener manufacturing of brass.

Enhancing the tribological aspects of machining operation by hybrid lubrication-assisted side-flank-face laser-textured milling insert

The objective of this study was to find ways of improving the machining performance of steel considering sustainable development by limiting the application of hazardous lubricant. The textures having the most advantageous shape were employed with hybrid lubrication consisting of graphite powder in combination with the MQL having best suited tribo-rheological properties. The genetic algorithm code generated for optimization of the machining parameters was one of its kinds that could consider categorical factors along with the continuous factors for optimization. It was found that the optimum machining condition was the low depth of cut, textured flank face impregnated with graphite powder and boric acid-dissolved MQL. Waviness in shape and the rougher inner surfaces of the textures produced through laser beam machining were found to allow the insert to act as a self-lubricating insert satisfactorily throughout the machining operation. Reduction in surface roughness of 64.4% was observed with the proposed technique. Providing an extremely minimal amount of lubrication to the textured tool using the developed technique led to the improved machining performance through cleaner production aiming at omitting waste.

An Analytical Model for Determining the Shear Angle in 1D Vibration-Assisted Micro Machining

In the metal cutting process, an increased shear angle generally leads to lower cutting forces and improved machining performance. It has been reported earlier that 2D vibration-assisted machining (VAM) increases the equivalent shear angle and decreases the chip thickness via an elliptical pulling motion of the tool rake face moving away from the deformed chip. Researchers have conducted several experimental and finite element studies and revealed that an increase of shear angle in 1D VAM as well and this process which started much earlier than 2D VAM is widely used in the machining industries. However, no systematic analysis of chip deformation in 1D VAM has so far been carried out regarding the equivalent shear angle. In this research study, several cutting tests have been conducted initially at a very low frequency (0.5 Hz) and the deformation of chip was found smaller compared to conventional machining. Based on the force analysis, an energy-based analytical model has been derived to evaluate the equivalent shear angle. The model was then verified at ultrasonic 1D VAM against cutting speed ratios. Four different metals have been tested including stainless steel, brass, annealed tool steel, and titanium. The results show that a lower speed ratio in ultrasonic 1D VAM will lead to a decreased chip thickness and as such decreased chip compression ratio. The developed model has been found to be able to well predict the equivalent shear angle for ultrasonic 1D VAM of several types of metal.

Optimization of Process Parameters of Electrical Discharge Machining Process For Performance Improvement

Unconventional machining methods are used where conventional techniques are unachievable, inacceptable or cost ineffective. Number of unconventional techniques has been developed to achieve special machining conditions. When these methods are engaged properly, they provide several benefits over conventional methods. High strength alloys can be machined easily, complicated contours and difficult geometries with close tolerances and better surface topograph can be developed using unconventional processes. One of the most popular unconventional machining methods is electrical discharge machining. In this paper, the detailed investigation has carried out to give an insight into the progression of research in the domain of spark machining and optimizing important process variables of this type of machining. It has been found from the available literature that optimization of process parameters of electrical discharge machining can improve machining performance pertaining to material removal and surface finish. Identifying the research gaps and are presented under the heading analysis and discussion. Conclusions drawn from this work will be useful in carrying out research in the sphere of unconventional EDM.

Parametric analysis of a green electrical discharge machining process using DEMATEL and SIR methods

To achieve safer machining environment, and minimize emission of harmful and toxic substances during electrical discharge machining (EDM) process along with improvement in its performance, this paper emphasizes on identifying the best parametric combination of a green EDM process using superiority and inferiority ranking (SIR) method. Decision making trial and evaluation laboratory method is also employed to visualize the interrelationships between the responses of the said process while splitting them into cause and effect groups. In this process, peak current, pulse duration, dielectric level and flushing pressure are the input parameters, while process time, relative tool wear ratio, process energy, concentration of aerosol and dielectric consumption are considered as the responses. The optimal parametric combination as derived employing the SIR method is validated with the help of developed regression equations for each of the responses, which show that the adopted approach outperforms the other popular optimization techniques in obtaining the best mix of the green EDM process parameters for having improved machining performance and less hazardous effects on the environment.

A DoE–TOPSIS method-based meta-model for parametric optimization of non-traditional machining processes

PurposeTo meet the requirements of high-dimensional accuracy and surface finish of various advanced engineering materials for generating intricate part geometries, non-traditional machining (NTM) processes have now become quite popular in manufacturing industries. To explore the fullest machining capability of these NTM processes, it is often required to operate them while setting their different controllable parameters at optimal levels. This paper aims to present a novel approach for selection of the optimal parametric mixes for different NTM processes in order to assist the concerned process engineers.Design/methodology/approachIn this paper, design of experiments (DoE) and technique for order preference by similarity to ideal solution (TOPSIS) are combined to develop the corresponding meta-models for identifying the optimal parametric combinations of two NTM processes, i.e. electrical discharge machining (EDM) and wire electrical discharge machining (WEDM) processes with respect to the computed TOPSIS scores.FindingsFor EDM operation on Inconel 718 alloy, lower settings of open circuit voltage and pulse-on time and higher settings of peak current, duty factor and flushing pressure will simultaneously optimize all the six responses. On the other hand, for the WEDM process, the best machining performance can be expected to occur at a parametric combination of zinc-coated wire, lower settings of pulse-on time, wire feed rate and sensitivity and intermediate setting of pulse-off time.Practical implicationsAs the development of these meta-models is based on the analysis of the experimental data, they are expected to be more practical, being immune to the introduction of additional parameters in the analysis. It is also observed that the derived optimal parametric settings would provide better values of the considered responses as compared to those already determined by past researchers.Originality/valueThis DoE–TOPSIS method-based approach can be applied to varieties of NTM as well as conventional machining processes to determine the optimal parametric combinations for having their improved machining performance.

Some observations in grinding SiC and silicon carbide ceramic matrix composite material

The ceramic has extensive applications in aeronautics and transportation industry because of outstanding properties, but the processing performance is poor. The carbon fiber-reinforced SiC matrix composite (Cf/SiC) is proposed to improve machining performance. The carbon fibers have important effects on surface quality and forces when machining Cf/SiC materials. But there are few investigations about the related contents. To fill these gaps by comparing SiC and Cf/SiC composites is the main objective of this study. The Cf/SiC materials were machined in two different directions. To explore the grinding mechanism, some evaluation parameters were investigated. The extension of cracks is the main removal method during grinding process of SiC. While matrix craze, fiber fracture, and interfacial debonding are the main remove methods of Cf/SiC composites. While grinding 2.5 D Cf/SiC material, fiber pullout, outcrop, fractures, wear, interfacial debonding, and matrix cracks were the major failure forms. During machining, the roughness of the machined surface decreased with reducing grinding speed vs, whereas the grinding depth ap and feed speed vw brought contrary effects. Meanwhile, the grinding forces gradually improved with increasing ap and vw, and decreasing vs. On the basis of conclusions, the surface roughness and grinding forces of the SiC and 2.5 D Cf/SiC materials could be derived. This series of analysis and researches provides useful technical support on understanding the grinding mechanism of SiC and 2.5 D Cf/SiC material.