Spindle Speed Research Articles

Discrete element method study of parameter optimization and particle mixing behaviour in a soil mixer

Soil mixing is an emerging research in the field of construction resource recovery. In this study, the mixing behaviour of soil particles in a mixer is numerically simulated by the discrete element method (DEM). A four-factor, three-level orthogonal experiment is designed to optimize the mixer design by selecting the fly-cutter speed, spindle speed, number of blades and fly-cutter diameter, using Lacey mixing index and power consumption as evaluation indicators. Then, the impact of soil cohesion and type on the mixing behaviour is investigated. The results show that the optimal parameter combination of this experiment is 280 rpm fly-cutter speed, 40 rpm spindle speed, 4 blades and 250 mm fly-cutter diameter. This optimal combination reaches a comparatively uniform state mix in 5.9 s with an average power consumption of 704.11 W. In addition, the wear and tear of the mixer increases as soil cohesion increases, while the mixing quality of materials declines, resulting in a “shaft hugging” phenomenon. The mixing efficiency varies greatly among different soil types, but the radial and tangential velocities have a similar law. This work can provide some guidance for the optimization design of a mixer and study of soil mixing.

Optimization of turning process parameters on EN8 unalloyed steel-based on MCDM methods

This research article is about optimizing turning parameters to find the best control parameter settings for maximum MRR and minimal tool wear. The experiment was performed on EN8 steel using the HSS S200 tool and input parameters were spindle speed, feed rate, depth of cut. Vegetable-based fluids were chosen as coolants for maintaining the sustainability of the operation.L9 orthogonal array design was used for making a combination set of 4 factors and 3 levels of control parameters. The Taguchi-based optimization technique was the subject of analysis with the TOPSIS, GRA & ARAS methods. The ideal control parameter settings for TOPSIS & GRA were discovered to be spindle speed 210 rpm, Feed rate 0.142 mm/rev, Depth of cut 1.5 mm, and Soya bean oil. For the ARAS method, it was found that 210 rpm spindle speed, 0.142 mm/rev feed rate, 1.0 mm depth of cut & Soya bean oil presented the optimal control parameter settings. Coolant shown maximum contribution over MRR & Tool wear. Finally the perfection of TOPSIS, GRA & ARAS results was validated by a prediction test & confirmation experiment.

Parametric optimization of dry-turning of Nickel-Chromoly steel with various cutting tool using WASPAS method

Many contemporary researchers have proposed the concept of dry machining, which has numerous benefits, ranging from the avoidance of adverse impacts on individuals as well as the ecosystem to the a number of cost cutting during machining, but it also has many disadvantages, such as an increase in the structural and thermal stresses of the tool. For the extent of cutting forces has a substantial effect on the creation of heat, toolwear, surface-finish, and the precision of the workpiece, determining cutting forces during machining operations can be one way to attain this and assess the machine-ability of a material. This study deals with cutting force investigation while dry turning AISI 4340 steel. Keeping the feed rate fixed and varying the spindle speed along with three different cutting inserts (PVD coated, uncoated, and CVD coated), the components of cutting force (thrust (Fx), feed (Fy), and cutting (Fz)) were investigated. The Weighted Aggregated Sum Product Assessment (WASPAS) technique combined with the Taguchi method was employed to minimise the cutting force and fetch the optimum result. ANOVA was performed to determine the most relevant variables influencing cutting force. Finally, convergence of the result with previous studies and a confirmation test were also done. It was found that CVD-coated cutting inserts induced minimum cutting force while turning AISI 4340 steel at low spindle speed.

Use of Spinning Roller in Cylindrical Densification; Spring back in Black Poplar, Larch and Cedar of Lebanon after Densification

Wood materials have been the solution to many needs throughout history due to their unique positive properties. By improving the properties of wood materials, their areas of use can be expanded and ensured that they are preferred. The densification process is one of the studies carried out to improve wood material properties. With densification, the physical and mechanical properties of the wood material are improved. There are many different methods used for densifying wood materials. While the densification process brings many positive properties to the wood material, an undesirable situation such as spring-back after the process is the negative side of the densification process. In this study, black poplar (Populus nigra L.), larch (Pinus nigra Arnold) and cedar of Lebanon (Cedrus libani A.Rich.) trees were shaped into cylinders on a lathe. After that, densification processes were carried out on the lathe machine using the spinning roller designed and manufactured for this purpose. Densification processes were carried out at 0.081, 0.121, and 0.202 mm/rev feed, at 200 and 400 rev/min, and 0.5 and 1 mm densification depths. The spring-back rates after densification in three different types of cylindrical wood materials were investigated. Theoretical and experimental spring-back amounts of test specimens whose surfaces were densified under different densification conditions were interpreted. When evaluated in general, the highest densification rate was obtained in black poplar wood species, 0.081 mm/rotate feed, 200 rpm spindle speed and 1 mm depth of densification. The lowest spring-back ratio was obtained in larch tree species, 0.121 mm/rotate feed, 400 rpm spindle speed and 1 mm depth of densification. The highest densification percentage was obtained in black poplar tree species, and the lowest in larch tree species. The lowest percentage of spring-back was obtained in the larch tree species and the highest in the black poplar tree species.

Multi-Objective Optimization of Process Parameters in Longitudinal-Torsional Ultrasonic Vibration Face Grinding CFRP

Due to its superior characteristics, carbon fiber reinforced plastics (CFRP) have been widely used in aerospace and other fields. However, their effective and economical processing remains a challenge. The purpose of this paper was to experimentally investigate the influence of several machining parameters, namely spindle speed, cutting depth, feed rate, and grit size on different machining performances, i.e., grinding force, and surface roughness through longitudinal-torsional (L&T) ultrasonic vibration grinding CFRP. The response surface methodology with a Box—Behnken design was used to create the experiments. The fitting mathematical models of grinding force and surface roughness were established separately to explore the interaction between the machining parameters and the impact on machining results. With the purpose of improving the surface quality and reducing the grinding force, the NSGA-II was used for multi-objective optimization to obtain the Pareto optimal solution. Compared with the initial experimental parameters, the optimized results can significantly improve the surface roughness and reduce the cutting force.

Experimental and statistical investigation into surface characteristics in micro milling of bottom pouring/gravity stir cast Al6061 alloy

Micro milling offers the best way to create micro channels; however, the burr formation and surface roughness of the micro channel are difficult to control. Micro channel fabrication and their characterization of stir cast Al6061 are rarely investigated. In the present study, Al6061 alloy was processed by the bottom pouring stir casting method. The micro channels were fabricated on a base and stir cast Al6061 alloys using TiSIN-coated micro end mill tools. The influence of micromachining parameters such as spindle speed, feed rate, and depth of cut on burr formation, cutting force, burr size, and surface roughness was investigated. A comparison was made between the findings obtained from the micro milling of the base and stir cast Al6061 alloys. The surface morphology of fabricated micro channels was analysed and correlated with the roughness profile to understand the channel profile and burr formation. The top burr formation mechanism in stir cast Al6061 alloy was investigated in detail. Low feed rate, low depth of cut, and high spindle speed produced the micro channel with fewer burrs, low surface roughness, and low cutting forces. At the optimum parameter, stir cast Al6061 alloy showed an approximate 420%, 16%, and 300% increase in Fy, Fz, and Ra, respectively, as compared to the base Al6061 alloy. Adhesion wear, built-up edge, and microchipping were found to be the main tool wear mechanisms in micro machining of stir cast alloy. This study directs the choice of cutting parameters for the stir cast micro milling process.

Energy-saving and noise-reducing integrated task allocation model for machining systems and its application

Abstract In this paper, firstly, based on the application model of optimal scheduling of machining system for green manufacturing, two application models of the energy-saving scheduling model and energy-saving and noise-reducing scheduling model in a multi-model framework are combined, and the resource environment coefficient matrix of the two application models is established as well as the solution process is studied with the parallel machine problem. Then the system's architecture is constructed, and its basic operation flow, functional modules, etc., are designed and conceived. The application of the system is studied in conjunction with a gear machining workshop of a machine tool factory, and the machining system's energy and noise reduction performance is verified based on experiments. The results show that the energy consumption of the machining system is reduced by 0.514 kW-h by machining only the above six gear parts with a small difference in the maximum machining completion time and that the spindle speed has the most significant effect on the machine tool machining noise at a significance level α of 0.05. The analysis of this study verifies that the energy-saving and noise-reducing scheduling arrangement method can reduce the system machining energy consumption and noise, which is important for green manufacturing.

Influence of tool pin profile on the mechanical strength and surface roughness of AA6061-T6 overlap joint friction stir welding

This study presents the tensile strength and surface roughness resulting from friction stir welding (FSW) on the lap joint method using AA 6061 –T6. FSW is conducted by comparing three different tool pin shapes: hexagon, thread, and square. Overlap welding using the FSW method is challenging if machine parameters, such as spindle speed and feed rate, are incompatible. The experiment was conducted using a conventional milling machine with a spindle speed of 1400 -1750 rpm and a feed rate of 20 – 30 mm/min. The results show that a spindle speed of 1750 rpm and a feed rate of 30 mm/min using a square tool pin results in 83.5088 MPa ultimate tensile strength and 0.85 µm surface roughness (Ra), which is much better than hexagon and thread type tool pins. In addition, the overall results on all three tool pin shapes show that higher processing parameters increase tensile strength and surface roughness. This study revealed the effect of parameters on AA6061 –T6 and the resulting implications of mechanical strength and surface roughness.

A geometric approach to milling stability uncertainty

Deterministic solutions for the milling stability boundary are provided by frequency-domain, time-domain, and semi-discretization methods. While these deterministic solutions are valuable, it is essential to consider the uncertainty in the predicted stability boundary to enable optimum milling parameter selection. Prior efforts have implemented Type A (statistical) uncertainty evaluations. This paper provides a Type B (other means) analysis, where the stability uncertainty is represented by offset boundaries based on user-selected uncertainties in spindle speed and axial depth. The geometric approach is demonstrated for a selected milling system using a frequency-domain stability solution.

Experimental investigation on cutting force and machining parameters optimization in in-situ laser-assisted machining of glass–ceramic

Glass-ceramic is a typical hard and brittle material that is difficult to use for ultra precision machining. In order to improve the machining quality of glass–ceramic, orthogonal experiments on in-situ laser-assisted machining (LAM) of glass–ceramic were carried out with cutting force as the characteristic value. The maximum reduction in the resultant force of cutting force in in-situ LAM was 56.13%. The contribution order of each machining parameter to reducing cutting force is: spindle speed > laser power > feed speed > cutting depth. Response surface methodology (RSM) was used to conduct experiments and establish a regression model for predicting cutting force. The influence law of four machining parameters on cutting force was studied through three-dimensional response surface. The optimal combination of machining parameters to minimize cutting force obtained through RSM optimization is: spindle speed 400.51 rpm, feed speed 0.03 mm/rev, cutting depth 18.91 μm, laser power 74.78 W. The RSM experiments were trained, predicted, and optimized using artificial neural network (ANN) and genetic algorithms (GA). The fitting values of the ANN model are highly consistent with the experimental values of RSM. The optimal machining parameter combination obtained through GA optimization is: spindle speed 400 rpm, feed speed 0.01 mm/rev, cutting depth 20 μm, laser power 75 W. Experiments were conducted using the optimal machining parameters of RSM and ANN respectively, and the results showed that ANN is more ideal for optimizing machining parameters and predicting minimum cutting force. This study provides guidance and reference for glass–ceramic in-situ LAM and parameter optimization method for cutting force.

Study on the Milling Machinability of Bamboo-Based Fiber Composites

Bamboo-based fiber composites, known as recombinant bamboo, have emerged as a new material in the construction and decoration industry. With its excellent mechanical and ornamental properties, recombinant bamboo is gaining popularity. However, its high hardness and abrasion resistance pose challenges in the milling process. To address this, we conducted an experimental study to investigate the milling machinability of recombinant bamboo. We studied the impact of various factors—fiber angle, feed rate, and spindle speed—on the tangential and normal roughness of milled surfaces. Our findings indicated that increasing the spindle speed within an acceptable range can effectively mitigate issues such as carbonization and endface cracking on a milled surface. Additionally, we developed a prediction model to assess the probability of end splitting in recombinant bamboo. This research aimed to enhance the milling quality of recombinant bamboo, improve control over surface roughness, reduce the likelihood of end splitting, and, ultimately, expand application possibilities.

Comparison of different 3Y-TZP substrates for the manufacture of all-ceramic micro end mills with respect to the cutting edge radius and the tool wear

In micro milling, size effects such as the ratio of uncut chip thickness to cutting edge radius result to high mechanical stresses. The tools need to be able to withstand these, with as little tool wear as possible. Cemented carbides are currently the tool substrates of choice. Technical ceramics are highly wear resistant as well, but they are not yet used in micro milling. To utilize their potential in micro cutting processes, we previously identified Y-TZP as the best ceramic for this purpose. Compared to cemented carbide, they exhibit only marginal tool wear when micro milling PMMA.To investigate whether the 3Y-TZP characteristics influence the performance of all-ceramic micro end mills, three different substrate materials were used to manufacture tools that were tested by micro milling of PMMA. Further varied factors were the feed per tooth and the spindle speed. The initial cutting edge sharpness of the tools and the tool wear were used to quantify the results. One substrate was found to result in lower cutting edge radii and a more stable manufacturing process than the others. Also, a feed per tooth dependent wear behavior was observed.

Investigation of Heat Annealing and Parametric Optimization for Drilling of Monel-400 Alloy

A nickel-based copper alloy known as Monel-400 is extensively applied in many industries including aerospace, marine engineering, and nuclear power generation, owing to its exceptional characteristics such as extreme tensile strength and toughness, excellent corrosion resistance, and the ability to retain shape even at extremely high temperatures. Traditional methods of drilling Monel-400 alloy are difficult due to quick tool wear and poor surface polishing, resulting in expensive machining costs. In this study, a technique called heat annealing was implemented to externally heat-treat the Monel-400 alloy material before the drilling process. Cutting force, surface roughness, and tool wear were used as the responses to investigate the effect of heat annealing and the drilling parameters on the machinability of Monel-400. The results revealed that the cutting force (Fz) and surface roughness (Ra and Rt) could be reduced by 33%, 31%, and 25%, respectively, after annealing at 700 °C compared to the results of the drilled Monel-400 at room temperature. It can be observed that the maximum improvement can reach 42% of Fz, 35% of Ra, and 59% of Rt while annealing Monel-400 at 1000 °C. A significant reduction was observed in the tool wear for machining the annealed material, which minimized the tooling and overall machining cost. Regarding the effects of the drilling process on the considered responses, the results revealed that the spindle speed has a greater effect on the cutting force, whereas the feed rate has the most significant effect on Ra. The significance of the drilling input parameters on the outputs is determined by analysis of the main effect plots and surface plots. Subsequently, the multi-objective genetic algorithm (MOGA) is used to identify the optimal parametric conditions for minimizing the cutting force and surface roughness of the drilled holes. The optimized values achieved via multi-objective optimization are the cutting force, Fz = 388–466 N, and the surface roughness, Ra = 0.17–0.19 μm and Rt = 3–3.5 μm, respectively.

Influences of Main Machining Process Parameters and Tool Wear on The Machining Damage Generated During Edge Milling CFRP Composites

Machining Carbon Fibre Reinforced Plastics (CFRPs) composites are typically accompanied by the appearance of machining damage which strongly impacts the structural integrity of composite parts during their service lives. Studying the correlation between machining damage and its affected factors has still been an open issue. Hence, it is necessary to do more research. This study focuses on investigating the influences of main process parameters and tool wear phenomenon in terms of machining length on the machining quality which was characterized by the surface roughness criterion, the ten-point max, Rz. A full factorial design of experiments was conducted including three levels of feed speed and two degrees of spindle speed. The results revealed that machining damage was mainly influenced by process parameters at a small machining distance, whereas at a longer machining distance, tool wear had a dominant effect on the machining quality than machining parameters. These findings could provide guidelines for selecting suitable machining parameters to enhance the machining quality of CFRP.

Experimental Analysis and Application of a Multivariable Regression Technique to Define the Optimal Drilling Conditions for Carbon Fiber Reinforced Polymer (CFRP) Composites.

Carbon fiber reinforced polymers (CFRPs) are interesting materials due to their excellent properties, such as their high strength-to-weight ratio, low thermal expansion, and high fatigue resistance. However, to meet the requirements for their assembly, the drilling processes involved should be optimized. Defects such as delamination, dimensional errors and poor internal surface finish can lead to the premature failure of parts when bolt-joined or rivet-connected. In addition, the characteristic anisotropy and heterogeneity of these materials, and the issues related to the temperature reached during drilling, make it difficult to obtain optimal cutting parameters or to achieve high material removal rates. This research focuses on the optimization of the CFRPs drilling process by means of experimental analysis-varying the feed and spindle speed-for two different types of commercial drills-a twist tool and a dagger tool. An automatic image processing methodology was developed for the evaluation of the dimensional accuracy and delamination of the holes. The optimization was carried out using a multi-objective regression technique based on the dimensional deviations, delamination and surface finish. The areas with favorable machining conditions have been delimited for both tools and the results indicate that the twist tool allows one to achieve more productive cutting conditions than the dagger tool, when the combination of low feeds and high spindle speeds are the conditions to be avoided.

Experimental study on ultrasonic vibration assisted grinding of GCr15SiMn bearing steel

Many problems of GCr15SiMn high-carbon chromium bearing steel have been found in the ordinary grinding (OG) process. Aiming at the problems of high grinding force, low residual compressive stress and low surface quality, ultrasonic machining technology is combined with OG. The test of ultrasonic vibration assisted grinding (UVAG) GCr15SiMn high carbon chromium bearing steel is carried out. The residual stress, surface roughness, grinding force, and surface morphology are analyzed by changing machining parameters. The research showed that as the grinding depth and feed speed become larger, the grinding force increased, when the spindle speed rises, the grinding force becomes smaller. In the test range, with the ultrasonic amplitude from small to large, the grinding force from large to small. The ultrasonic grinding force is 27.8% lower than that of OG. The surface roughness increases with increasing grinding depth and feed speed and decreases with increasing spindle speed and ultrasonic amplitude, and at an amplitude of 6 μm, the surface roughness is reduced by 27% compared to OG. When the feed speed and grinding depth are lowered or the ultrasonic amplitude is increased, the surface residual compressive stress is increased. Compared to OG, it is increased by more than 13.5% under the same parameters. At the same time, the phenomenon of burrs and surface tears can be reduced, and the surface quality of the workpiece becomes better.

Temperature Control Performance of a Built-In Motor Spindle by Developed Temperature Feedback Control System

The temperature control performance of a developed temperature feedback control system was experimentally investigated. The control system was based on a real-time temperature control of a cooling fluid. In particular, this study focused on the temperature control performance of a built-in motor spindle that used the developed temperature fedback control system. The built-in motor used in the study had water cooling jackets. The temperature of the built-in motor spindle was measured and feedback into the developed temperature feedback control system. Temperature control accuracy of the built-in motor spindle under steady state was then assessed. Furthermore, the effects of the time-variant changes in spindle rotation and ambient temperature on the performance of the temperature control system was investigated. The results of the experiments show that the temperature control accuracy of the built-in motor spindle under steady state condition was ±0.03°C. The temperature control performance of the built-in motor spindle under changes in the rotational speed of the spindle was examined. The experimental results show that the temperature change of the spindle could be suppressed to a maximum of approximately 0.3°C under transient state during sudden change in spindle speed. In addition, the effects of the changes in ambient and cooling water temperatures, which simulated actual environmental operating conditions, on the spindle temperature were investigated. The results show that the change in the spindle temperature could be suppressed by approximately less than ±0.1°C. These experimental results indicate that the developed temperature feedback control system achieved high temperature control accuracy and high response for the built-in motor spindle. In particular, the developed control system successfully controlled the time-variant change in the generated heat, thereby improving the thermal stability of the machine tool spindle.

An energy survey to optimize the technological parameters during the milling of AISI 304L steel using the RSM, ANN and genetic algorithm

ABSTRACT The world’s population growth has led to increased demand for products, which requires enormous energy consumption. Therefore, energy savings are becoming a primary objective for industrial sectors. This study uses artificial intelligence, specifically response surface methodology (RSM), artificial neural networks (ANN) and genetic algorithms (GA), to optimise machining parameters in the mechanical manufacturing sector. The findings demonstrate that the use of artificial intelligence can reduce the amount of energy used in machining operations, increasing both productivity and cost. According to the analysis of variance, the depth of cut a p and the feed rate V f are the most influential factors on total specific energy consumed (TSEC). Meanwhile, spindle speed is the most influential factor for energy efficiency (EE). EE increases when there is an increase in the rate of material removal as opposed to decreasing total specific energy. The study also shows that the multi-objective optimisation with the genetic algorithm can reduce TSEC by 44.13% and increase EE by 14.63%. The optimal cutting parameters given by the genetic algorithm are the spindle speed, feed, depth of cut and number of teeth.

An Experimental Investigation of Surface Quality in Single Point Incremental Forming of Cu-Al Composite Sheets

Single-point incremental forming (SPIF) has been developed as a customized substitute of traditional sheet metal forming techniques. SPIF is a great method for rapidly prototyping sheet metal objects, although it faces challenges in achieving surface quality and thickness distribution. In this investigation, sheets of Cu-Al bimetallic composite were formed utilizing a hemispherical-headed tool with a variety of step depths, spindle speeds, forming speeds, layer arrangements, and lubrication types. Surface roughness and minimum thickness were evaluated as response parameters in relation to the significance of process variables. The best surface quality was attained with 0.4 mm step depth, 750 mm/min forming speed, and 1500 rpm spindle speed with liquid lubrication support for both types of layer arrangements. Layer arrangement and lubricant type were the decisive factors for the minimum thickness response parameters.

Experimental investigations on Inconel 625 using single point incremental forming

Single point incremental forming (SPIF), which can form sheets without any prior setup is an ideal option for prototype and batch production. Geometrical accuracy is a major challenge in the formation of Inconel 625 super alloys. Parameters such as spindle speed, feed rate, step size and wall angle were considered to assess the influence of the forming factors on the geometric accuracy of the Inconel 625 super alloys. The investigation was performed on 100 × 100 mm flat sheets with a thickness of 1 mm. Sheet metal with the desired shape was designed and developed using computer aided design (CAD) software. A circular shape was manufactured via incremental forming using a hemispherical tool with a 5.8 mm radius. A tool path was generated using Fusion 360 software to perform SPIF on Inconel 625 super alloys by varying the parameters. When experimental and simulation data were examined, significant agreements were found.Thickness thinning of sheets were most affected by wall angle. Multi-stage solutions will improve the formation limits.