Vertical Milling Research Articles

Optimisation and modelling of burr formation during face milling of rolled steel (AISI 1040) using Taguchi approach

ABSTRACT Burr formation on the edge of the machined part during face milling is a common phenomenon. Highly precise and accurate parts are required to be burr free. Generally, deburring (secondary operation) is performed to remove the burr, which leads to the cost of the part. The aim of this study is to obtain minimum exit burr by optimising the input parameters at primary stage of the face milling operation. Effect of machining parameters (cutting velocity, feed per tooth, axial depth of cut), and machining strategies (rolling direction, cutter offset, soaking time during heat treatment) are taken into consideration. Taguchi’s L27 matrix is selected for the design of experiments. Face milling of rolled steel (AISI 1040) is performed on vertical milling centre using titanium nitride coated carbide inserts. Exit burr is evaluated as a signal to noise ratio. The significance level and percentage contribution of parameters are calculated using analysis of variance. Cutter offset has shown maximum contribution followed by cutting velocity. Burr reduction of 58.4% is observed during a confirmation test. Finally, multi-variable linear regression is employed to generate second-order empirical model. Adequacy of model is checked by residual analysis.

Автоматичне управління шириною листа на станах гарячої прокатки

Controlling the sheet width using a computer on heavy plate mills (HPM) and roughing mill trains (RMT) of wide-strip hot rolling mills (WSHRM) must ensure the set width of the sheet (roll), rectangularity of the sheet (roll) in the plan characterized by the uniformity of the sheet width in the middle part along its length, as well as at the front and rear ends, and the minimal trimming of the front and rear defective ends of the sheet (so-called “tongues” and "swallow-tail"). Forming the desired sheet width is carried out either in jointly working vertical and hori-zontal mills in a reversible mode or in a continuous non-reversible group of mills (vertically-paired – horizontal). With the leading participation of the authors, there were carried out the development of the automated process control system (APCS) and studies aimed at regulating the width in the RMT of mill 560. Mathematical models describing natural and additional ex-pansion and the requirements for their accuracy are presented in famous scientific works. To assess the accuracy of the characteristics, experimental studies were conducted on a laboratory mill. The rolling conditions in the RMT of mill 560 were simulated during the research. The analysis of experimental data and data obtained through the calculation using various formulas provided in literary sources showed that all known models do not meet the accuracy require-ments set by the APCS for the RMT of mill 560. Therefore, new mathematical models of ex-pansion were developed. The paper presents the mathematical models for changing the width in the middle part along the length of the roll and the models for changing the width at the “head” and “tail” of the roll. A method for determining a roll gap is described, which implements the law of change of the gap of vertical rolls that eliminates deviations in the width of the roll from the initial (before rolling) value. The testing of the developed mathematical models under the conditions of the technological process in the RMT of mill 560 showed their ability to solve the problem of controlling the sheet width in real time.

Исследование процесса взаимодействия предохранительных колес двухроторных вертикальных фрез со штамбом дерева

Исследование процесса взаимодействия предохранительных колес двухроторных вертикальных фрез со штамбом дерева

Optimization of Sustainable Process Parameters of Friction-Stir Welding of Aluminium Alloy by Taguchi Method

In the current paper, AA6101-T6 aluminium alloy was subjected to friction stir welding (FSW) utilizing a vertical milling machine. Alloy plates were welded in butt position to provide a virtually flat interface, using a tool shape that was carefully selected. Because of the excessive generation of heat via the tool and workpieces during friction stir welding, substantial deformation in the nugget zone is seen. The mechanical attributes of the base metal at the joint are significantly impacted by an excessive variation in temperature at the weld. In this experiment, mechanical properties-related changes through the FSW process are kept to a minimum to achieve high tensile strength. The tool’s rotating speed (measured in rpm), the workpieces' traverse speed (measured in mm/min), and the tool tilt angle were chosen as the parameters to regulate the weld quality. As a result of its 44% contribution, the rotating speed parameter is shown to be the most beneficial one for stir welding. The metric determining transverse speed contributes the least, at 19%. For effective stir welding, such as high strength welds, defect-free welds, short welding times, low welding costs, etc., it is preferred that the tool rotational speed parameter be concentrated. By using sustainable Taguchi approach to optimize the chosen process parameter, high tensile strength is achieved at the welded connection.

Comparisons of Structured Surface Floors for Pool Boiling Enhancement at Low Heat Fluxes: Hands-On Learning Setup for Heat Transfer Classroom

Various enhanced surfaces have been proposed over the years to improve boiling heat transfer. This paper introduces an experimental setup designed for boiling demonstration in the graduate-level Heat Transfer course. The pool boiling performance of water under atmospheric pressure of 1.025 bar is investigated by using several structured surfaces at heat fluxes of 28 and 35 kW/m2. Surfaces with holes, rectangular grooves, and mushroom fins are manufactured by an NC-controlled vertical milling machine. The heat flux versus excess temperature graph is plotted by using thermocouple measurements of water and base temperatures of the boiling vessel. The separation, rise, and growth of individual vapor bubbles from the surface during boiling were recorded with a digital camera. The results for the plain surface are compared to the Rohsenow correlation. The enhancement of heat transfer coefficient (h) ranged between 15% - 44.5% for all structured surfaces. The highest heat transfer coefficient enhancement is observed between 41% - 56.5% for holed surface-3 (405 holes) compared to the plain surface. The excess temperature dropped around 29% - 34% for holed surface-3 (405 holes) compared to the plain surface. The heat transfer coefficient increases as the spacing between channels or holes decreases. While the bubbles on holed and mushroomed surfaces were spherical, the bubbles on the flat and grooved surfaces were observed as formless. The suggested economical test design could be appropriate to keep students focused and participating in the classroom.

Effect of tool rotation speed on microstructure and mechanical properties of underwater friction stir welding 6061 aluminium alloy

This work presents the experimental investigation of the effect of tool rotation speed (TRS) on the mechanical properties of the 6061-T6 aluminium alloy weld joint in the underwater friction stir welding (UFSW) process. The experiments are conducted with four different TRS, 710, 900, 1120, and 1400 rpm, and a constant welding speed (WS) of 20 mm/min, respectively. The welding is performed under the water in the butt joint configuration on the vertical milling machine (Model HMT FN2H). The experimental result shows that the average grain size decreases and tensile strength and hardness increases on increasing the TRS up to mid-range of the TRS and further increasing the TRS the trend of grain size and tensile strength and hardness are increases and decreases, respectively. The maximum tensile strength value is 190 MPa, and the minimum grain size is 5 µm at 1120 rpm. Additionally, the optimum condition of tensile strength and weld zone shape is compared with the conventional friction stir welding process, and it is found that tensile strength is increased by 20% and smaller weld zone shape are observed in underwater friction stir welding process. The brittle fracture dominance is observed at lower TRS and ductile dominance fracture in 900, 1120, and 1400 rpm of the weld joint.

Effect of tool rotation speed on mechanical properties of underwater friction stir welding of 6061-T6 and 5083-H12 aluminium alloys

This work presents an experimental investigation of the effect of tool rotation on the mechanical properties of 6061-T6 and 5083-H12 aluminium alloys in the UFSW weld joint. The experiments are conducted in a vertical milling machine (model no. HMT FN2H) at four different tool rotation speeds (TRS), such as 710, 900, 1120, and 1400 rpm, at constant welding speed (WS) of 63 mm/min. The welding was performed under the water in the butt joint configuration in which the 6061-T6 workpiece material is placed on the retreating side (RS) and 5083-H12 on the advancing side (AS). The results show that the performance of the weld joint quality depends on the TRS. The shape and size of the weld nugget zone (WNZ) and thermo-mechanically affected zone (TMAZ) increase with increasing the TRS. The tensile strength of the weld joint and average grain size of the stir zone (SZ) increases and decreases respectively on increasing the TRS 710 to 1120 rpm. Further increasing the TRS, the tensile strength of the weld joint and average grain size of SZ decreases and increases respectively. Additionally, the fracture surface shows the brittle dominance fracture mode at 1400 rpm, and 710 to 1120 rpm weld joints show the ductile fracture mode.

Effectuates of Direct Particle Injection Friction Stir Process tool for the Al/SiC surface coating fabrication

The Project is investigated the Direct Particle Injection Friction Stir Processing Tool (DPI-FSP) fabricating the Al/SiC Surface Coating (SC). The FSP using vertical milling machine which was performed the tool rotation speed 1000 rpm at traverse feed 20 mm/min.Peculiarity of the tool is the deletion of material preparation (Making grooves or Drill hole for filling the reinforcement particles) and continuously injected the reinforced particles during the process. The tool is fabricated the thin surface coating of Al/SiC. As a result, The micrograph is revealed that homogenous distribution of SiC particles and peneterated 340 µm thick on the surface matrix . The SC exhibited 55% of the increase in hardness as compared the base material. The X-ray diffraction results are showed that the no intermetallic was discovered besides the SiC particles. The SC wear test results is exhibited the superior frictional coefficient of 0.71 than the Empty Pass.

Antibacterial Coating on Filtration Membranes for Treatment of Cutting Fluid

Abstract: Cutting fluids has greater significance in manufacturing processes to ensure work-piece quality, to reduce tool wear, and to improve process productivity. The specific chemical composition of an applied coolant should be strongly dependent on the scope of application. Even small changes such as presence of microorganisms such as Staphylococcus, Streptococcus, Pseudomonas, Alcaligenes etc. can influence the performance of cutting fluid and introduce risk of various skin diseases to the operator in the manufacturing processes considerably. In this project the antibacterial coating is brought into use by coating a thin layer of silver nano particles on a polypropylene filtration membrane. A coated and non-coated membrane was placed separately on the cutting fluid sump of a vertical milling machine. 10litres of cutting fluid with a Servo cut Soil content of 5% and distilled water with a concentration of 95% were used in the machine while a milling process was carried out. Then a sample of cutting fluid (about 250mL) was taken from the tank and preserved for testing purposes after passing through the filter membranes. On the same cutting fluid, the machine was run for another two days, and a third sample was taken at the end of the fourth day. The samples collected were tested at Azyme Biosciences Pvt Ltd for bacterial count (CFU/ml) and the results showed that the CFU/ ml in the sample filtered through the non-coated polypropylene filtration membrane was higher than in the sample filtered via coated polypropylene filtration membrane.

Indonesia's Blue Economy Potential: Salt Pond in Nagekeo, East Nusa Tenggara

Allegedly, based on the diversity of the maritime by Indonesia, our country has a very potential wealth of marine resources. These resources can be utilized for its used as blue econommy approach. This country’s marine resources that can be utilized as a national economic potential is a salt industry. With the wealth of the saline water that we have, Indonesia is still importing salt because there is an imbalance between demand and domestic production. The purpose of this journal is to find out the potential for briny ponds in Indonesia to be used to reduce the dependence on national imports. To handle this problem, there are several efforts to maximize our national productions of saline pond in Nagekeo District, East Nusa Tenggara (Nusa Tenggara Timur). Along with the modernization and technology, there is several branches of innovation and technology to increase the effectiveness of Indonesia’s Sea Salt Industry such as Geomembrane Prism House, Vertical Axis Mill Pump, and the Smart House Salt Maker (SHASA). By adopting these technologies, it is expected that the production of marine salt farmers will be able to severely reduce salt imports and make Indonesia a successful and independent maritime country.

A study on the influence of the graphite flakes disintegration method on their dispersed composition, particle shape, and flotation performance

Cast iron cooling generates iron-graphite flakes that may serve as a source of flaked graphite, a valuable material, in high demand by Russian manufacturers. This study was aimed at analyzing the changes in the dispersed composition and shape of iron-graphite flake dust particles when ground under various conditions. The grinding equipment comprised ball mills with metal and porcelain grinding media and a centrifugal impact grinding unit (a vertical shaft mill) with dynamic particle classification. The sieve analysis method and a laser particle size analyzer were used to study dispersion of the initial dust and its grinding products. The material composition and changes in the shapes of flake particles were studied using optical geometry analysis methods and scanning electron microscopy (SEM). Varying distributions of particles by size classes and grain agglomeration probability rates have been established for different grinding methods. The influence of the grinding method on the redistribution of magnetic particles is shown. It has been established that centrifugal milling of graphite flakes intensifies particle aggregation, but also contributes to higher performance in flotation separation as compared to ball milling. The following has been observed for centrifugal milling vs. ball milling: an increase in the yield by 3 %; higher mass fractions of carbon in fine and coarse product flotation concentrates by 22.7 and 17.5 %, respectively; and a 5 times lower concentration of the magnetic fraction.The work was carried out with the financial support of the Russian Science Foundation as part of a grant for fundamental scientific and exploratory research in 2022–2023, agreement No. 22-27-20068, and with the participation of the TsKL NII «Nanostali» of the NMSU.

Efficient machine learning model to predict fineness, in a vertical raw meal of Morocco cement plant

Soft sensor enables computing parameters that can be physically impossible to measure. This work aims to develop a soft sensor for raw meal fineness in a vertical roller mill of a cement plant. In previous research, some key indicators of the process were ignored. It is well known that vertical raw meal is feeded with heterogenous material that impacts raw meal fineness, and therefore, can deteriorates prediction accuracy of the soft sensor. To deal with this constraint, one-year history of industrial data was exploited and processed by a robust multivariate outlier identification method, followed by process expert outlier verification. Then a particular attention was given to process and material quality parameters using a statistical method to test parameters significance on fineness based on data variance calculation. Eight process and four quality parameters were retained to develop robust nonlinear model using artificial neural network: Bayesian regularization and Levenberg Marquart, then compared with Support vector regression with different acquisition function and kernels to tune and select optimum model hyperparameters. The best model performance was obtained with the Bayesian regularization algorithm.

Characterization of mechanical and metallurgical properties of AA6063 foam developed by friction stir precursor deposition technique

The aim of this work is to develop the precursor-based Al foam by deposition of AA6063-T6 consumable rod, filled with a foamable mixture of titanium hydrate (TiH2) and aluminium powder over a mild steel substrate through friction stir deposition (FSD) technique. The AA6063-T6 consumable rods were drilled with different hole strategies ranging from 1 to 6 holes on the periphery of the rod, which were filled with foaming powder of the same composition. To perform the deposition, a conventional vertical milling machine was used. The deposited material presents a fine equiaxed grain whose size is much lower than the as-received material, indicating dynamic recrystallization during friction stir deposition. The results also show that the foaming particles decrease the hardness values of the produced deposits when compared to those of base material. It has been observed that 4 and 5 numbers of holes in the consumable rod are more suitable for foam development and the foaming particles are more uniform as obtained from energy dispersive spectrum (EDS) and scanning electron microscope (SEM) analysis. It is also observed that by increasing the number of holes in the rod more than 5 promote the formation of defects in the developed foam. The consumable rod with 4 and 5 holes shows the linear plateau stress in the compressive test as compared to 1, 2, 3 and 6 holes.

Flat-end mill machining analysis of processed CrMnFeCoNi high-entropy alloys

ABSTRACT High-entropy alloys are emerging materials and are widely studied at the synthesis and characterization levels. Their machinability study and product realization are still at a nascent stage. Conventional machining operations are necessary to ensure part assembly and surface quality. Hence, end-mill machining is carried out to check the machinability of the most ductile equiatomic and non-equiatomic CrMnFeCoNi high-entropy alloy (HEA) with a green manufacturing concept. Theoretical and experimental analyses examined the effect of percent composition of an element in a high-entropy alloy and machining parameters (spindle speed, depth of cut and feed per tooth) on the cutting forces, chip morphology, machined surface topography, surface micro-hardness and tool wear mechanism. Kistler dynamometer installed in CNC vertical milling machine is used with AlTiN-coated tungsten carbide tool to record the cutting forces and moments. The microstructure anisotropy induced by low vacuum induction melting of varying compositions of elements in high-entropy alloys influenced the machining results. Feed force values were higher for the non-equiatomic HEA sample than for the equiatomic CrMnFeCoNi HEA. SEM and EDS mapping has revealed microhole and microcrack surfaces after machining. Equiatomic CrMnFeCoNi HEA has shown the highest microhardness of 984 Hv than the non-equiatomic HEA sample.

Tribological Investigation of Textured Surfaces in Starved Lubrication Conditions

The present work investigates the friction reduction capability of two types of micro-textures (grooves and dimples) created on steel surfaces using a vertical milling machine. The wear studies were conducted using a pin-on-disc tribometer, with the results indicating a better friction reduction capacity in the case of the dimple texture as compared to the grooved texture. The microscopic images of the pin surface revealed deep furrows and significant damage on the pin surfaces of the groove-textured disc. An optimization of the textured surfaces was performed using an artificial neural network (ANN) model, predicting the influence of the surface texture as a function of the load, depth of cut and distance between the micro-textures.

Selection of cutting tool for desired surface finish in milling Machine using Taguchi optimization methodology

In this paper, Taguchi's method for optimisation has been showcased to select a cutting tool on vertical milling machine when processing with (i) carbide insert tool and (ii) polycrystalline diamond tool, subjected to specify surface finish i.e., Ra 1.6 maximum. The milling machine parameters are validated for Depth of Cut (DOC), Feed Rate, and Cutting speed with tools configuration. The experiment results show that the different cutting tool with optimal milling parameter combinations provides variable surface finish values. After obtaining variable data, the analysis was conducted with the team's support and decided the best suitable tool for machining, providing a surface finish under a controlled limit. A comparative experiment has been shown to optimise the tool selection for procurement. A comparative study is being conducted between two tools one is of carbide and the second one is of polycrystalline diamond Analysis.of.Variance (ANOVA) is being applied to analyse the adverse effect of process parameters on the machining process. This work helps in the procurement during Design For Manufacturing (DFM) process. For this, the Taguchi methodology is being utilised to optimise tool selection. The research concludes that the Taguchi methodology is optimum for solving the nth issues with minimum trials and helps to select the tool.

Experimental studies on the flow pattern regimes of particles-liquid mixtures in an inner circulation vertical mill

A vertical mill platform for inner circulation is constructed to improve the grinding efficiency. A transparent plexiglass grinding chamber is utilized to study the influence of solids density, particle size, solid volume fraction and agitator speed on the variation and transition of flow pattern regimes. The change regulations of rotor speed to just circulation and complete circulation as well as system energy consumption are analyzed, the empirical correlations for predicting the rotor speed to just circulation and complete circulation are proposed based on the experimental data of particles-liquid mixtures. The results indicate that the flow of particles-liquid mixture shows four different flow patterns with the increase of the agitator speed. In addition, the process of transition between flow patterns is different when the volume fraction of particles is lower or higher than 20%. The just circulation speed and the complete circulation speed of particles increase as the volume fraction of particles increases. The total system power consumption increases slowly when the volume fraction of particles is lower than 40%; but it increases sharply if the solid volume fraction exceeds 40%.

Objective speckle pattern-based surface roughness measurement using matrix factorization.

A method for the measurement of profile parameters of both isotropic and anisotropic surfaces is presented using the objective laser speckle imaging technique. The surface parameters are characterized in terms of a singular value decomposition method-based metric derived from the initial key contributing singular values of the speckle pattern. A simulation study is performed with random Gaussian anisotropic surfaces generated as a function of the correlation lengths in both x and y directions. In the experimental demonstration, the proposed method is verified with metallic samples having distinct surface roughness processed through widely used machining operations viz., vertical milling, and grinding. A brief discussion about the extent to which the minimum number of singular values that are sufficient to evaluate the profile parameters in the context of experimental results is provided. The method supports the measurement of profile parameters of higher magnitude in the realm of non-contact topographic measurement techniques. The experimental results substantiate the practical applicability of the proposed method.

WEAR ANALYSIS OF VERTICAL COAL MILL PLATE

Vertical Coal Mill (VCM) is equipment for grinding and pulverizing coal into micron size. Rotary kilns then use the powders as fuel burners. The VCM has a housing section equipped with a lining plate as a wear and tear protector. The housing comprises segments with similar thicknesses and materials that are severe to wear due to gas-carrying solid particles hitting the surface. The specific material resilient to abrasion is required to extend operating services. This study aims to determine the wear properties of Hardlite and Everhard C500LE on the lining plate. Characterization of the samples, including composition, microstructure, hardness, and wear test. Microstructure observation shows that the more extensive and profound the wear marks formed, the higher the volume of exfoliated material. The test results show that the Fe-Cr-C hard-facing alloy significantly affects the hardness value of a material and its wear resistance. The hardness test results showed an average Hardlite overlay layer hardness value of 703 BHN (N/mm2), almost double that of Everhard C500LE.

Friction Stir Welding of Different Aluminum-Silicon Alloy Compositions Utilizing Conventional Vertical Milling Machine

Friction-Stir Welding (FSW) is a solid-state procedure for welding two plates in which there is relative motion between the tool and workpiece, which creates the heat required for the material of the two edges to join by atomic diffusion. The present research article focuses on friction stir welding of dissimilar aluminum-silicon alloys utilizing a vertical milling machine and altering process parameters. Moreover, testing is done on the weld joints for the best process parameter. The process parameters considered in the present work for joining dissimilar aluminum alloys primarily were a constant tool feed rate of 63 mm/min and three varied tool rotational speed rates of 710, 1000 and 1400 rpm. Mechanical characterization of weld joints, such as tensile, hardness, microstructural studies and surface roughness tests, were used to identify the most optimal parameter. The results indicated that Al-Si alloys having Al-5%Si with Al-12%Si FSW joints welded using 1000 rpm tool rotational speed proved to have better hardness and lesser surface roughness while, Al-Si alloys having Al-12%Si with Al-17%Si FSW joints, had better hardness and roughness properties when welded using 1400 rpm tool rotational speed. Concerning the ultimate tensile strength, Al-Si alloys having Al-5%Si with Al-12%Si and Al-12%Si with Al-17%Si FSW joints welded using 1400 rpm tool rotational speed offered better results.