Optimal Combination Of Process Parameters Research Articles

Characterization and Parametric Optimization of Performance Parameters of DLC-Coated Tungsten Carbide (WC) Tool Using TOPSIS

In this work, we have deposited the diamond-like carbon (DLC) coating on the tungsten carbide (WC) tool insert using the thermal chemical vapor deposition (CVD) method. For the growth of DLC coating, sugarcane bagasse was used as a carbon precursor. Raman spectroscopy, a field emission scanning electron microscope (FESEM), and X-ray diffraction (XRD) were used to confirm the presence of DLC coating on the tungsten carbide tool inserts. The hardness tests were also performed for inspecting the microhardness induced by the self-developed DLC coating on the tungsten carbide (WC) tool insert. To determine the optimum process parameters for the turning operation on an aluminum (6061) workpiece using a self-developed DLC-coated tungsten carbide (WC) tool insert, we have applied the technique for order preference by similarity to ideal solution (TOPSIS) methods. The process parameters considered for the optimization were feed rate, cutting speed, and depth of cut. Whereas chosen response variables were flank wear, temperature in the cutting zone, and surface roughness. TOPSIS is utilized to analyze the effects of selected input parameters on the selected output parameters. This study in this paper revealed that it was advantageous to develop the DLC coating on the tungsten carbide tool inserts for the machining applications. The results also revealed that a 0.635 mm depth of cut, feed rate of 0.2 mm/rev, and cutting speed of 480 m/min were the optimum combination of process parameters.

Multi Response Optimization of ECDM Process Parameters for Machining of Microchannel in Silica Glass Using Taguchi–GRA Technique

In this work, machining of microchannel in silica glass was successfully carried out using electro chemical discharge machining (ECDM) process. The experiments were planned according to L27 orthogonal array with applied voltage, stand-off distance (SOD), electrolyte concentration, pulse frequency and pulse-on-time (TON) as control factors. The material removal rate (MRR), overcut (OC) and tool wear rate (TWR) were considered as response characteristics. In this study the effects of control parameters on MRR, OC and TWR have been investigated. The increase in applied voltage, electrolyte concentration and pulse on time lead to the improvement in the output characteristics which is attributed to formation of heavily crowded hydrogen bubbles and further coalescence of hydrogen bubbles promotes the occurrence of sparks which resulted in higher values of MRR, OC and TWR. The multi-objective optimization of ECDM was carried out through grey relational analysis (GRA) method. Optimal combination of process parameters achieved from GRA was 45 V applied voltage, 25 wt.% electrolyte concentration, 1.5 mm SOD, 400 Hz pulse frequency and 45 μs TON. ANOVA for GRG study revealed that the applied voltage (70.33%) was most significant factor affecting output responses followed by electrolyte concentration (11.69%), pulse frequency (4.98%) and SOD (4.13%). Furthermore, the regression equations were formulated for the optimum combination to predict the collaboration and higher-order effects of the control parameters. In addition, confirmation test was conducted for the optimal setting of process parameters and the comparison of experimental results exhibited a good agreement with predicted values. The microstructural observation of machined surface for the optimum combination was carried out.

Study on laser cladding process parameters of Fe-based alloy based on numerical simulation

Using 45 steel as the substrate, laser cladding Fe-based alloy powder on the surface was proposed to improve the surface wear resistance and hardness, and partially replace the cold working die steel in the small batch production stage. ANSYS Workbench was used to simulate the heat transfer and temperature field distribution in the laser cladding process of iron base alloy. The thermal properties of the substrate and the cladding material were set up, and the finite element model was established by Gaussian heat source. The temperature field under different laser cladding process parameters was simulated to obtain the temperature distribution of molten pool. According to the metallurgical bonding between the substrate and the coating, and taking the dilution rate of the cladding layer as the basis of quality evaluation, the optimal process parameter combination of laser cladding Fe-based alloy powder of 45 steel substrate is determined as follows: laser power 1400W, scanning speed 8mm/s, spot diameter 3mm. The results provide technical data support for the engineering application of laser cladding of Fe-base alloy on 45 steel substrate.

A new high-speed observation system for evaluating the spark location in WEDM of Inconel 718

Abstract Wire electrical discharge machining (WEDM) is a good machining method for nickel-base superalloy, which is a key material in aero-engine, rocket engine and nuclear reactor. Experimental data indicate that the spark location along the thickness direction is usually uneven in WEDM. This phenomenon will be harmful to the usability and reliability of the parts machined by WEDM, especially in aerospace. However, the spark location is very difficult to observe directly with high precision due to the narrow cutting kerf. In view of this situation, a new high-speed observation system is proposed to evaluate the spark location during the continuous discharge process for the first time. The discharge spark, in turn, passes through heat-resistant glass, optical filter, focusing lens and digital high-speed videocamera. A series of image processing methods and centroid methods are utilized to acquire the spark location in this system. It can be observed that the number of discharge sparks of all regions in decreasing order is: middle region, lower region and upper region. The maximal standard deviation (St) of spark location can reach up to 0.137. Thereafter, a group of discharge experiments are carried out to analyze the relations between the process parameters and spark location evenness. An optimal combination of process parameters for even spark location is obtained, which can produce a standard deviation (St) of spark locations as low as 0.039. Eventually, the relation between spark location and machining characteristics is also illustrated. Ra can be decreased by 32.6% without reducing machining efficiency based on the process parameter optimization for even spark location.

Research on Thermal Inkjet Technology Based on CFD

In this paper, a thermal inkjet printing simulation model is established in the CFD simulation platform, and the influence of inkjet driver parameters and ink physical parameters on the printing process is studied by numerical simulation. The evaporation-condensation model is coupled with the VOF multiphase flow model in Fluent software to establish a thermal inkjet printing process simulation model. Based on the orthogonal test method, we investigate the influence of fluid physical parameters (ink viscosity, surface tension) and inkjet driver parameters (heater temperature value) on droplet formation by changing the physical parameters of the material and the boundary conditions of the model. Through the comparison of the results, exploring the adjustment rules of thermal inkjet technology and obtaining the optimal combination of material and process parameters for high-quality ink drop formation.

Fuzzy-MOORA Based Optimization of Machining Parameters for Machinability Enhancement of Titanium

The aim of this study is to determine the optimal combination of process parameters when machining commercially pure titanium grade 2. The unification of Multi objective optimization based on ratio analysis (MOORA) and fuzzy approach has applied to optimize the process parameters. Three process parameters i.e. cutting speed, tool overhang, and microhardness have been varied at three levels each and a total of twenty seven experiments have been conducted based on Taguchi’s L27 design of experiment technique. Cutting force, tool flank wear, and average surface roughness have been considered a machinability indicators to measure the process performance. Feed rate and depth of cut have been kept constant. Successful optimization is done and results show that machining titanium at higher cutting speed (140 m/min) and higher tool overhang length (65 mm) with medium hardness (1934 HV) results in lower cutting force, tool flank wear, and surface roughness. Outcomes of the present work reveal that the hybrid fuzzy-MOORA method is convincing enough to obtain the best process parameter combination for the best machinability while machining titanium type difficult-to-machine materials.

Effects of different process parameters on mechanical properties and microstructures of hot stamping boron steel

Hot stamping process has been increasingly used to produce automotive parts with ultra-high-strength property. Thus, increasing the crashworthiness of new generation vehicles and reducing car body weight could be simultaneously obtained. Taking boron steel B1500HS as the research object, this paper built a set of hot stamping experiment equipment that could monitor the temperature of sheet metal and die in real time. The initial forming temperature, contacting pressure, and pressure holding time in hot stamping process were examined under the condition of continuous hot stamping when the die temperature got into dynamic stability. The microstructures and mechanical properties including tensile strength, elongation, and hardness of stamped blank were used as quality evaluation indexes. For B1500HS boron steel sheets with the thickness of 1.2 mm, the optimal process parameter combination of hot stamping process comes true when the initial forming temperature is 800 °C, the contacting pressure is 20 MPa, and the pressure holding time is 10 s. The high-quality hot stamping parts with compact martensite phase could be finally obtained at the tensile strength of 1495 MPa, elongation of 7%, and hardness of 510 HV.

A Two-Stage Filter Split-Optimization Approach for Obtaining Multiple Solutions with Identical Objective Value

A tremendous amount of work has been done in the recent years in the optimization of input parameters, however, current optimization techniques can only provide a single optimal input process parameter combination. Although alternative techniques have been developed to provide multiple solutions with identical objective values, these techniques have low efficiency when searching for multiple solutions. In this paper, a two-stage filter split-optimization approach is proposed to obtain multiple solutions, at a higher efficiency than for a single-objective optimization problem. The aforementioned tasks are accomplished by first performing an initial split-optimization and then performing a second optimization after excluding input parameters from having their range split into sub-ranges based on the results of the initial optimization. The proposed approach enables the algorithm to explore input parameters that have a more significant impact on the objective function, thereby enabling it to find multiple optimal solutions more efficiently. The proposed approach was validated by using it to optimize the input process parameters of an electrochemical machining problem with five input parameters. The results from the case study show that though the proposed approach provided fewer optimal solutions it was able to obtain them at twice the efficiency when compared to the original method.

Electrochemical technique for paper mill effluent degradation using concentric aluminum tube electrodes (CATE).

In this study, Taguchi experimental design was used to the optimize operating parameters for the degradation of paper mill effluent using electrochemical (EC) process with two-dimensional concentric aluminum tube electrodes (CATE). For this purpose, four significant experimental factors were used in four levels pH (6-9), electrolysis time (10-40min), voltage (6-12V)and surface area (357-624cm2). The process parameters were optimized, through performing L16 orthogonal array of Taguchi technique, for the removal of chemical oxygen demand (COD) and turbidity. The percent COD and turbidity reductions were transferred into an accurate S/N ratio for a largervalue is the better (LBT) response. The study presents a unique method of finding optimum combination of process parameters to illustrate their effect on the turbidity and COD reduction. The treatment conditions for the maximum elimination of the pollutants were second level of pH (7), third level of ET (30min), fourth level of voltage (12V) and second level of surface area (446cm2). The confirmation experiment results were within the confidence intervals (CI) indicating an acceptable agreement between predicted and observed values. Based on the p-values, the electrolysis time and voltages were found to be the most significant factors for both COD and turbidity reduction. The findings of research indicated, that the Taguchi method can be used successfully for the treatment of paper industry effluent by electrochemical technique.

Application of laser power diode on leather cutting and optimization for better environmental quality measures

Since the leather materials are used in various industries such as shoes, fashion, furniture and automotive industries, it is essential to introduce laser technology on cutting leathers with intricate geometries under better environmental conditions. In this investigation, an effort was made to analyze the effects of laser power diode on environmental measures such as carbonization, striations and dross formation in leather cutting. It was attempted to compute the optimal factors using TGRA methodology. It was inferred that laser power diode cutting process can eliminate the striations and dross formation on leather cutting due to elimination of mechanical impact energy. Laser power diode can reduce the carbonization effect on leather cutting owing to the lower and concentrated energy. The optimal process parameters combination of laser power diode based leather cutting process was found with tolerance of 4.6%. Standoff-distance highly influences on determining the lower carbonization region and kerf width in laser power diode based leather cutting process.

The influence of magnetic field orientation on metal mixing in electromagnetic stirring enhanced wire feed laser beam welding

The application of the electromagnetic stirring from an oscillating magnetic field can improve the metal mixing in wire feed laser beam welding. However, the extra parameters introduced in this technique make the selection of an optimal combination of process parameters more difficult. In the current study, besides the commonly concerned magnetic flux density and frequency, the influence of the magnetic field orientation (magnetic field angle) on the transport of filler metal is studied numerically and experimentally. Ex-situ X-ray fluorescence spectrometer measurements are used to map the metal mixing in the final weld. A three-dimensional transient multi-physical model is developed to reveal the deeper physical essence, considering the coupling between heat transfer, fluid flow, keyhole dynamics, element transport and magnetohydrodynamics. The spatial distribution of the laser energy on the keyhole wall is calculated by a ray tracing algorithm. The results show that the magnetic field with smaller angle with respect to the transverse direction provides better penetration capacity, and its stirring effect can reach the lower part of the molten pool. Therefore, the smaller magnetic field angle produces better metal mixing. A constant downward flow is formed at the lower part of the molten pool when magnetic field of 10° angle is applied, which brings the filler metal to the root region. As the magnetic field angle increases to 40°, the beneficial downward flow changes into a constant upward flow, resulting in a concentration of the filler metal in the upper region. This study provides further insight of the underlying physics in the electromagnetically enhanced laser beam welding, which may guide the optimization of parameters to achieve property homogeneity or to avoid potential defects.

Application of TOPSIS for multi response optimization of Process Parameters in dry hard turning of AISI 52100 steel

In the present work by employing the Technique for order of preference by similarity to ideal solution (TOPSIS) machining parameters optimization is performed with polycrystalline cubic boron nitride (PCBN) tools while AISI 52100 steel hard turning (HT). Based on the CCD of RSM, 32 experimental runs were performed by varying cutting speed, feed, depth of cut, nose radius, and negative rake angle to identify the optimal level of the process parameters. In this study, the multiple performance characteristics measured are machining force, surface roughness, and workpiece surface temperature. To ascertain the impact of cutting parameters on responses, Analysis of Variance (ANOVA) was deployed. An optimum combination of input process parameters for the multiple performance characteristics should be as follows: speed 200 rpm, feed 0.1 mm/rev, depth of cut 0.8 mm, nose radius 1.2 mm, and negative rake angle 45º leading to the value of optimum response variables machining force 561.163 N, Surface roughness 0.507μm and workpiece surface temperature 84.38°C.

Analysis and optimization of laser drilling process during machining of AISI 303 material using grey relational analysis approach

Surface roughness and heat-affected zone (HAZ) are the important features which influence the performance of the laser-drilled products. Understanding the influence of laser process parameters on these responses and identifying the cutting conditions for simultaneous optimization of these responses are a primary requirement in order to improve the laser drilling performance. Nevertheless, no such contribution has been made in the literature during laser drilling of AISI 303 material. The aim of the present work is to optimize the surface roughness (Ra) and HAZ in fibre laser drilling of AISI 303 material using Taguchi-based grey relational analysis (GRA). From the GRA methodology, the recommended optimum combination of process parameters is flushing pressure at 30 Pa, laser power at 2000 W and pulse frequency at 1500 Hz for simultaneous optimization of Ra and HAZ, respectively. From analysis of variance, the pulse frequency is identified as the most influenced process parameters on laser drilling process performance.

WITHDRAWN: Experimental investigation and optimization of die-sinking EDM of grade 630 stainless steel using Taguchi approach

Abstract This article proposes an investigation of the effects of different arguments of EDM process on the quality of machining and to attain the optimal combination of process parameters, hence, the machined parts quality will be optimized. Experiments are conducted on the pieces varying parameters. The work piece and electrode materials used for machining are stainless steel of grade 630 and copper tungsten, respectively. The process parameters considered are pulse on-time T ON , pulse off-time T OFF , flushing pressure P F and peak current I peak . The range of values varied for T ON is15µsec, 25 µsec, 35 µsec and 45 µsec, T OFF is about20 µsec, 50 µsec, 70 µsec, 90 µsec, I peak are 6A, 10A,14A, 18A and flushing pressure is about 2Mpa,4Mpa,6Mpa,and 8Mpa.In addition, it also investigatesthe effects of these input parameters on output response as surface roughness(SR) and material removal rate (MRR). Further, optimization also done by using Taguchi technique by considering L16 orthogonal array with the help of MINITAB 19 software. Extensive results disclosethat experimental values of both SR and MRR are better than the predicted valuesand shown that Taguchi approach is quite effective for single-objective optimization.

Optimization of process parameters in Electro Chemical Discharge Machining of silica glass through Analysis of Means

In recent years, the Electro Chemical Discharge Machining (ECDM) process has advanced as a substitute for machining of conductive and non-conductive materials. Optimization of the process parameters plays a crucial role in improving the quality of the processed components. The machining of microchannel in silica glass has been successfully attempted in present work by considering Analysis of Means (ANOM) of ECDM process parameters. The experiments were planned using Taguchi’s L9 orthogonal array with applied voltage, stand-off distance (SOD), electrolyte concentration (EC) and pulse on time (TON) as process parameters. The Material Removal Rate (MRR), Machining Depth (MD) and Overcut (OC) were observed as output characteristics. The ANOM study revealed that the error between experimental and predicted values of MRR, MD and OC are 4.22%, 1.92% and 3.46% respectively. Stand-off distance was found to be the most significant factor followed by pulse on time, applied voltage and electrolyte concentration from ANOVA. Confirmation test was performed by setting the optimum combination of process parameters and the predicted values from regression analysis exhibited a good agreement with experimental results.

Numerical Simulations and Experimental Studies on the Formability of Drawing Quality Steel in Single Point Incremental Forming

Based on numerical simulation and experimental studies the process parameter optimization on the formability using a 1 mm thickness Drawing Quality Steel(CR2) in Single Point Incremental Forming (SPIF)was studied. The sample shape chosen was the hayperbolic cone and fabricated using different parameter leveles. A model of numeric simulation was developed in ABAQUS explicit and then experimentally verified using a CNC milling machine. The influence of three significant control factors, namely tool radius, feeding rate, and step depth on the formability was studied. Optimization of process parameters was conducted using the L9 Taguchi orthogonal array. For optimal formability, to assess the optimum combination of process parameters, a signal noise (S/N) ratio was used. The percentage contribution of the method parameters to formability was determined by the Study of Variance (ANOVA). The findings of the study indicated that the depth of the step followed by feed rate and tool radius, was the dominant factor influencing formability. Furthermore, a good agreement (<8% error) between the numerical simulation and experimental study was seen. The study based on the Taguchi configuration of the study shows that at a feed rate (A2) 1000 mm/min, with tool radius (B1) 8 mm, and with step depth (C2) 0.8 mm, the optimal conditions for maximum formability were achieved.

Data-driven design strategy in fused filament fabrication: status and opportunities

Abstract The advent of additive manufacturing (AM) has brought about radically new ways of designing and manufacturing of end-use parts and components, by exploiting freedom of design. Due to the unique manufacturing process of AM, both design and process parameters can strongly influence the part properties, thereby enlarging the possible design space. Thus, finding the optimal combination of embodiment design and process parameters can be challenging. A structured and systematic approach is required to effectively search the enlarged design space, to truly exploit the advantages of AM. Due to lowered costs in computing and data collection in the recent years, data-driven strategies have become a viable tool in characterization of process, and researches have starting to exploit data-driven strategies in the design domain. In this paper, a state-of-the-art data-driven design strategy for fused filament fabrication (FFF) is presented. The need for data-driven strategies is explored and discussed from design and process domain, demonstrating the value of such a strategy in designing an FFF part. A comprehensive review of the literature is performed and the research gaps and opportunities are analysed and discussed. The paper concludes with a proposed data-driven framework that addresses the identified research gaps. The proposed framework encompasses knowledge management and concurrent optimization of embodiment design and process parameters to derive optimal FFF part design. Contribution of this paper is twofold: A review of the state-of-the-art is presented, and a framework to achieve optimal FFF part design is proposed.

QbD approach to downstream processing of spray-dried amorphous solid dispersions – a case study

In the current study, we demonstrate a structured approach to downstream process development for spray dried amorphous solid dispersions. Direct compression is generally not suitable due to typically poor flow of spray dried powders in tablets. Roller compaction (RC) is therefore the method of choice to enable spray dried dispersion downstream processing. Here, a structured experimental design of RC process parameters was used. The objective was to identify process conditions that lead to improved powder flow without compromising tablet robustness. Ten blends were compacted using different process parameters, and subsequently compressed into tablets. The impact of process parameters on granules and tablet properties was analyzed. We demonstrate that compaction force, gap and mesh aperture have major impact on RC outcomes. A combination of large gap and low force was identified as optimum combination of RC process parameters leading to powder flow improvement that could guarantee low tablet weight variation and at the same prevented loss of blend compressibility.

Statistical Modelling to Study the Implications of Coated Tools for Machining AA 2014 Using Grey Taguchi‐Based Response Surface Methodology

Milling is the surface machining process by removing material from the raw stock using revolving cutters. This process accounts for a major stake in most of the Original Equipment Manufacturing (OEM) industries. This paper discusses optimizing process parameters for machining the AA 2014 T 651 using a vertical milling machine with coated cutting tools. The process parameters such as cutting speed, depth of cut, and type of the cutting tool with all its levels are identified from the previous literature study and several trial experiments. The Taguchi L9 Orthogonal Array (OA) is used for the experimental order with the chosen input parameters. The commonly used cutting tools in the machining industry, such as High‐Speed Steel (HSS) and its coated tools, are considered in this study. These tools are coated with Titanium Nitride (TiN) and Titanium Aluminum Nitride (TiAlN) by Physical Vapor Deposition (PVD) technique. The output responses such as cutting forces along the three‐axis are measured using a milling tool dynamometer for the corresponding input factors. The input process parameters are optimized by considering the output responses such as MRR, machining torque, and thrust force. Grey Taguchi‐based Response Surface Methodology (GTRSM) is used for multiobjective multiresponse optimization problems to find the optimum input process parameter combination for the desired response. Polynomial regression equations are generated to understand the mathematical relation between the input factor and output responses as well as Grey Relational Grade (GRG) values. The optimum process parameter combination from the desirability analysis is the HSS tool coated with TiAlN at a cutting speed of 270 rpm and a depth of cut value of 0.2 mm.

Multi-variable optimization for surface roughness and micro-hardness in MQL assisted face milling of EN31 steel using Taguchi based grey relational analysis

Abstract In the course of this analysis Taguchi approach with grey relational test data was carried out to provide an appropriate set of processes to encourage surface roughness and micro-hardness of EN 31 alloy. The optimal surface roughness and micro hardness were achieved as per TGRA. In addition, the appropriate set of process parameters were calculated by grey relational degree to enhance the quality of surface. The variance analyses for grey relationship grades have shown that the feed rate is the most important factor that affects surface integrity in EN-31 milling. Finally, confirmation experiments which significantly improve several quality characteristics have demonstrated the optimal combination of process parameters. The results of the confirmatory experiment showed that Taguchi method is an effective method of evaluating the available grey relation analysis. The desired surface quality cutting parameters for the EN-31-alloy milling in the MQL condition.