Cylindricity Error Research Articles

Minimum Zone Evaluation of Cylindricity Error Based on the Improved Whale Optimization Algorithm

Minimum Zone Evaluation of Cylindricity Error Based on the Improved Whale Optimization Algorithm

Dynamic uncertainty evaluation of cylindricity error based on Bayesian deep neural network propagation method

Most of the existing methods for measuring and evaluating product geometric tolerances are for static processes, which use lower dimensions, are more complex to calculate, and have poor traceability and dynamic manageability and control of the measurement process. In this paper, a dynamic evaluation model of cylindricity error uncertainty based on the Bayesian deep neural network propagation method is proposed. Firstly, the input random variable sampling sample containing error uncertainty is generated by proposing the improved Monte Carlo sampling method (IMCS), which has the characteristics of homogeneity and validity; then the principle and construction process of a Bayesian neural network model are introduced to generate the propagation model of multidimensional random error variables; further, the Gaussian mixture model is trained by the Monte Carlo method, and the probability density function of the target response is generated by using the Gaussian mixture model. Through numerical experiments, test analysis of bearing outer rings, and comparison with ISO standard methods, the results show that the model based on the dynamic Bayesian deep neural network propagation method can correctly and effectively assess the uncertainty dynamically, and the whole estimation process is stable.

Influence of HSS drill coatings on surface finish and cylindricity of AA6061/C/ZrO2 composite in CNC drilling operations under dry conditions

Abstract This study aims to evaluate the effect of HSS drill tool coatings, namely single-layer TiN, single-layer AlCrN, and double-layer AlTiN + TiSiXN (Durana), on the surface roughness and cylindricity of AA6061 (90 wt%)/C (5 wt%)/ZrO2 (5 wt%) hybrid composite material processed by the stir casting method. The fabricated sample was examined for the uniform particle distribution of reinforcements using Scanning Electron Microscope. The drilling operation was carried out on the fabricated in a CNC machining center by setting the spindle speeds of 800, 1200, and 1600 rpm, depths of cut of 0.5, 1, and 1.5 mm, and feeds of 50, 100, and 150 mm/rev. An orthogonal array (L27) designed by Taguchi’s method was used as the design of the experiment for the optimization of the best cutting parameters and coating. Surface roughness and cylindricity errors were determined for the 27 experimental runs. Field emission scanning electron microscopic (FESEM) examination and Energy Dispersive Spectroscopy (EDS) were used to analyze the surface integrity and elemental composition, respectively. The results revealed that Durana had a significant effect on the surface substrate with minimum surface roughness (Ra) of 1.666 μm and obtained the minimum cylindricity error for the parameters of depth of cut 0.5 mm, spindle speed of 1200 and feed of 100 mm rev−1.

Unsupervised machine learning application in the selection of measurement strategy on Coordinate Measuring Machine

It is indisputable that some type of coordinate measurement system (CMS) is generally used to assess the quality of dimensional and geometric characteristics. Considering the required accuracy, flexibility, and speed of measurement, a CMM with a scanning sensor may offer the best performance. These measurement systems are very complex, and many factors affect the reliability of the measurement results. A Metrologist’s choice represents the greatest variability in the measurement strategy. Previous research has shown that the measurement results can be changed up to 100 % by choosing a different measurement strategy when evaluating the form error. This paper conducts a detailed study of the impact of the measurement strategy on the cylindricity error when measuring eleven workpieces with the same nominal characteristics, but different real characteristics described by roughness and the reference value of cylindricity. To examine the influence and importance of certain factors and their levels, design of experiment (DoE) and unsupervised machine learning techniques of PCA (Principal Component Analysis) and Multiple Correspondence Analysis (MCA), were used. The results suggest that depending on the real geometry of the workpiece, different factors with different percentages influence the output characteristic. The objective was to choose a uniform measurement strategy when measuring cylindricity on the CMM, while the prior information about the actual geometry of the workpiece is lacking.

Cylinder accuracy analysis of tangential turning of disk-like workpieces with increased cutting speed

Tangential turning, a precision high-speed finishing procedure, is crucial for achieving superior surface quality and dimensional accuracy in cylindrical workpieces. This advanced machining technique leverages tangentially applied cutting forces to minimize tool deflection and vibration, thereby enhancing the surface integrity of the final product. Despite its advantages, tangential turning poses challenges in maintaining cylindrical accuracy, necessitating a thorough investigation of cylindrical error. Cylindrical error, the deviation of the machined surface from a perfect cylinder, significantly impacts the functional performance of precision components. Factors such as tool wear, machine dynamics, and thermal effects can induce these errors, demanding comprehensive studies to optimize process parameters and tool paths. By thoroughly analyzing cylindrical error, manufacturers can refine tangential turning processes, ensuring high precision and consistency in high-speed finishing operations. This research underscores the importance of precision error analysis in advancing manufacturing capabilities and achieving stringent quality standards. Cylindrical accuracy is analyzed using the full factorial experimental design methodology to carry out practical cutting experiments, where the cutting speed, feed, and depth of cut were the altered variables. The cylindricity error, peak maximum departure, their ratio, and coaxiality are measured and analyzed. The main effect analysis and detailed study are elaborated using the determined equation. It is found that decreasing the studied parameters is advisable if increasing cylinder accuracy is needed.

Method of inclined hole axis adjustment based on geometric optimization and minimum zone theory

The machining accuracy of the axis position and spatial angle of the array microholes with high aspect ratio on the components of the high-end equipment manufacturing industry will directly affect the performance of the whole machine. A method of tilt hole axis adjustment is proposed in this paper. It utilizes geometric optimization and minimum zone theory to measure the position and spatial angle of the hole axis. This addresses the slight angle error that occurs after correcting the inclined hole axis using visual techniques. Based on the minimum zone criterion for the cylindricity error, the evaluation model is re-established through the inner and the outer loop and spatial projection, which includes roundness evaluation of the projection curve by an improved particle swarm optimization (PSO) algorithm and elliptic fitting by a geometric parameter method, so as to obtain the optimal solution of the axis vector and spatial angle. Experimental comparison with the theory above shows that the precision of the method proposed is better than that of the least squares method and the traditional PSO algorithm based on the minimum zone criterion. The research results indicate that the precision of the tilt angle is better than 0.03°, and simultaneously the rotation angle is better than 0.1° in the range of 1°. This experiment verifies the effectiveness and accuracy of the proposed method.

An experimental investigation into the influence of water column height in submerged mode of abrasive waterjet trepanning on the hole quality

Abrasive waterjet (AWJ) trepanning/drilling exhibits immense potential to realize holes of various shapes and sizes in a diverse range of materials, ranging from soft-and-ductile to hard-and-brittle, making it highly valuable for various industries. AWJ trepanning offers the advantage of not requiring tool changes to accommodate different hole shapes and sizes; adjusting the jet path can produce the desired hole geometry, proving exceptionally advantageous for mass production. However, the stochastic nature of the jet results in geometrical errors (diametric deviation, taper angle (α)), form errors (circularity error (Ce), cylindricity error (Cy)) and quality issues (damage region, edge radius (R), surface roughness (Ra), and waviness (Wa)). To address these issues, trepanning in submerged mode can be adopted as it attenuates the mist region and aggressiveness of the jet. This study analyzes the influence of the submerged mode of trepanning on the geometry, form, and quality of trepanned holes relative to the in-air mode. The study found that submerged trepanning produces a more consistent hole diametrical profile along the depth and minimizes the average Ce and α by 23.18 % and 29.20 %, respectively. The maximum Cy in in-air trepanning was reduced in submerged mode by 36.76 %. The average damage region and R reduced by 50.80 % and 35.49 %, respectively. The qualitative and quantitative analysis of the trepanned surface morphology is presented in-air and submerged mode: the results show that the Ra and Wa decrease at the hole entry and middle zone and increase at the exit zone. Finally, the process parameters level settings for achieving near-optimal trepanning responses (α, Cy, Ce, damage region, R, Ra, and Wa) suggested with the help of mean response- and parallel coordinate- plots. Micrographs of submerged trepanned surfaces show that the material removal mechanism (MRM) governs by shallower craters and grooves at the entry and middle zone of the hole, and at the exit zone, the MRM is random, in comparison to the in-air mode.

Experimental and Analytical Investigation of Performance of Liquid Metal Herringbone Grooved Bearings with Cylindricity Errors

Liquid metal herringbone grooved bearings (LM-HGBs) are customarily used in high-performance x-ray tubes to support the high-speed rotating anode and facilitate heat transfer from the anode to the coolant. This article investigates the impact of cylindricity errors on LM-HGBs performance through simulations and experiments. The analysis considers both the Reynolds equation modified by turbulence and the film equation incorporating cylindricity errors to construct the prediction model of LM-HGBs. An experiment rig was constructed to measure the friction torque of LM-HGBs. The predictions were validated by comparing to experimental results. The pressure distribution was predicted under different cylindricity errors. The test and experimental results demonstrate that cylindricity error impacts the uniformity of groove depth and has a significant effect on the friction torque of the bearings. Theoretical results reveal that concavity and convexity errors alter the pressure distribution and have opposing effects on bearing static and dynamic parameters. Decreasing the ratio of error amplitude to groove depth and the ratio of error amplitude to radius clearance can reduce the effect of cylindricity errors.

Manufacturing errors detection and visualization system for parts with complex internal cavity structural through industrial CT image

To address the challenge of detection and visualization manufacturing errors in part with complex internal cavity structures, this paper present a method based on industrial computed tomography (CT) image. First, a two-dimensional (2D) CT sequence slice images are obtained using fan-beam high energy industrial CT scanning, which is then reconstructed into a three-dimensional (3D) measurement model. The measurement 3D model is registered with the original design model, and the surface information of the part is obtained by segmenting the surfaces. The error between reference surface of original design model and test surface of measurement model is calculated. By comparing the error value with the tolerance, the detection result is obtained and analyzed. The developed software system enables areas that do not meet the tolerance requirements to be visualized. This method can detect manufacturing errors for part with complex internal cavity structures, such as planeness error, cylindricity error, verticality error, and parallelism error. This method provides a basis for assessing the manufacturing and processing quality of part with complex internal cavity structures.

Influence of shape errors and inertia effects on the error motion of the aerostatic spindle

In this study, an extended Reynolds equation incorporating the shape errors and the inertia effects of compressible fluid was formulated. The pressure-solving equation for the gas film was constructed using a second-order finite difference method. By combining the measurement data from the cylindricity of multiple shafts obtained from a cylindricity measuring instrument, the variation of the aerostatic bearing load capacity with the rotation of the shaft was calculated, both with and without considering the inertia effect. An experimental rig was also constructed to measure the error motion data of the corresponding shaft. The results of numerical analysis and experimental validation demonstrated that shafts with larger cylindricity error values exhibit greater deviations in the calculated bearing load capacity, which correspondingly leads to larger radial error motion values measured in the experiment. When the roundness error value of the shaft is small or the shaft speed is low, the influence of inertial effects on the calculation results of the load capacity deviation is minimal and can generally be disregarded.

Single sensor three point on-line measurement method of precision rolling bearings

With the continuous development of machining methods, it is necessary to explore grinding and measuring methods to ensure the fatigue life and improved accuracy of bearings. In this study, a single-sensor three-point (SSTP) on-line outer-diameter measuring instrument was designed to ensure the consistency of the machining accuracy of precision bearing rings. Moreover, the mathematical model of the measuring instrument was established. The roundness and cylindricity error measurements of the ring outer diameter of precision bearings A and B form different manufacturers of countries were compared and analyzed. In addition, the accuracy measurement of the experimental grinder was investigated through multidimensional experiments. The results demonstrated a measuring and repetitive accuracy of ±1.25 and 1 μm, respectively. The measuring results conformed to the 3 б principle. The measured outer diameter was within the actual value of the workpiece outer diameter ±3 б, and the accuracy was over 99.73%. The instrument did only measure the outer diameter, but also measured the waviness error. The outer diameter and rotating speed did not clearly affect the measuring accuracy. The use of a lubricating fluid reduced the contact resistance of the on-line measuring instrument and significantly reduced the absolute error of outer diameter measurement, which is beneficial in improving the outer diameter measurement accuracy of the instrument.

Cylindricity error evaluation based on an improved artificial gorilla troop optimizer

Cylindricity error evaluation based on an improved artificial gorilla troop optimizer

Effects of fiber orientations on fracture mechanisms in rotary ultrasonic drilling of carbon fiber reinforced plastic laminates

The fracture mechanisms of the carbon fibers seriously depend on fiber orientations which significantly influence the surface quality of carbon fiber reinforced plastics (CFRPs). Rotary ultrasonic drilling (RUD), possessing some excellent characteristics including the superior sidewall quality and high cylindricity error, offers a possibility for the efficient drilling of the CFRP components. In contrast, the effects of fiber orientations on fiber fracture mechanisms are still not fully recognized in RUD of CFRP composites. Incorporated with kinematic characteristics of the abrasive, a novel theoretical model was developed to quantitatively describe the effective orientation of the fiber. Afterwards, the drilling experiments with and without ultrasonic were conducted under the same parameters. The surface topographies of the hole sidewalls at various orientations were comparatively characterized to explore the fiber fracture mechanisms. Subsequently, the influences of these mechanisms and the drilling parameters the surface qualities were also investigated. Moreover, the bending failure mechanisms of the carbon fibers were explored through theoretical analysis. As a result, another fiber fracture mechanism, bending failure, was identified with the smooth fracture and micro-fragmentation topographies at upwind and leeward parts of the fiber cross-section, respectively. Ultrasonic superimposition by means of the immense inertia force of the abrasive promoted the micro-fracture of the carbon fiber. The weaker sustainment from the back-up materials brought about the serious bending failure of fiber oriented at 135°, while the axial load component aggravated the tensile fracture of the carbon fiber with the effective orientation of 45°. The critical moment of the fiber bending failure was also established, by incorporating the beam theory and linear elastic fracture mechanics. The fundamental investigation provided a favorable foundation for further optimizing the parameters to improve the drilling quality and efficiency in formal RUD of CFRP composites.

Optimization of drilling parameters in vertical machining centre drilling on magnesium AZ91D alloy under dry condition with Taguchi design

Drilling using a Vertical Machining Centre (VMC) remains a prevalent machining technique, even if current metal cutting processes have improved. Drilling settings on a VMC are optimized using the Taguchi technique to minimize surface roughness, hole diameter, and circularity error roundness test in this experimental investigation. In order to obtain the optimum process parameters in the VMC drilling on Magnesium AZ91D Alloys, L16 orthogonal arrays was formed by changing the four different speed, feed and end point angle. In the trials, an AZ91D alloy was employed and a variety of process factors, like drilling speed (250, 350, 450 and 550 rpm), feed rate 0.025, 0.05, 0.075 and 0.1 mm/rev), and end point angle (55, 75, 95 and 118°) were examined. Experimental results shows that a combination of slow speed (250 rpm), higher feed (0.1 mm/rev), and a medium end point angle (75°) resulted in the lowest roughness average value. It was possible to achieve the hole diameter accuracy by using the parameter at higher speed (450 rpm), higher feed (0.1 rev/min) and an end point angle of 118°. The lowest possible cylindricity error was perceived at 250 rpm speed, 0.01 mm/rev feed and 118° end point angle respectively. The lowest possible roundness error was perceived at 250 rpm speed, 0.05 mm/rev feed and 118° end point angle respectively. It was noticed from this experimental study and Taguchi technique, the surface roughness of the drilled hole is greatly affected by speed, feed and end point angle of the drill bit tool. Lower magnitude of drill tool speed and lower end point angles cause the good surface roughness values rather than the higher magnitude. The drilled hole’s diameter accuracy is significantly influenced by lower tool speed, higher feed rate and higher end point angle of the drill bit tool. The lower tool speed and higher end point angle of the drill bit tool are the two major factors, which are influenced the minimum cylindricity and roundness errors. It was observed from this experimental study, the lower drill bit tool speeds, higher tool feeds and higher end point angles are the important factors, which are significantly affected the quality of the drill holes during the machining of Magnesium AZ91D alloy in Vertical Machining Centre ((VMC) under dry conditions.

Study on helical milling of SS 304 with small diameter tools under the influence of minimum quantity lubrication (MQL)

The objective of the present work is to study the effect of minimum quantity lubrication (MQL) on the performance of helical milling for machining high-quality holes with a small-diameter tool. Helical milling with small tools (diameter < 5 mm) has been a challenging domain due to the problem of tool deflection, which deteriorates the hole quality and adversely affects the process efficiency. In this study, helical milling of stainless steel (SS 304) is carried to machine holes using a 3 mm diameter coated carbide tool in minimum quantity lubrication (MQL), and the performance is compared with dry and conventional flood cooling based on the hole quality and tool wear. The findings of this study reveal that MQL results in high-quality holes with the least circularity and cylindricity errors compared to dry and flood lubrication. Surface morphology study of the machined holes shows that the holes generated in MQL have smoother surfaces with no evidence of severe surface defects. MQL can also significantly mitigate the problem of tool deflection encountered in small-diameter tools and reduce tool wear by 33.3% and 21.7% compared to dry and flood lubrication, respectively. As per ISO 286-2 standard, hole quality up to grade H8 is achieved with MQL, while dry condition and flood lubrication yield hole quality corresponding to H9 grade. This study concludes that MQL-assisted helical milling is one of the sustainable alternatives for the production of high-quality small-diameter holes in stainless steel.

Modeling of process parameters on DSS 2205 through RSM, ANN, fuzzy under cryo-MQL process

Duplex stainless steel (DSS) 2205 is considered difficult to cut machine materials. Therefore, an advanced cooling technique, such as a hybrid Liquid carbon dioxide (LCO2)-Minimum quantity of lubrication (MQL) approach, is proposed for drilling duplex stainless steel 2205. In this research study, parametric optimization was performed by using the Response surface method (RSM) with the box-Behnken design of the matrix. For parametric optimization, select three input parameters: drill diameter, spindle speed, and feed rate, while hole deviation and cylindricity error are output responses. The Analysis of variances (ANOVA) test showed that spindle speed is the major factor that influences both responses, e.g., hole deviation and cylindricity error, with contributions of 38.90% and 59.42%, respectively. The modeling and predictive abilities of developed Fuzzy logic system (FLS) and Artificial neural network (ANN) to the comparison of experimental results. It was also found that the predicted values from regression analysis, artificial neural networks, fuzzy logic interfaces, and the proposed method were in good agreement with actual experiment results. Also, the Artificial neural network model provides a minimum % of error of 1.36% and 2.44 %, respectively responses compared to other models.

Investigation of Abrasive Aqua Jet Hole Making (AAJHM) parameters using desirability analysis on Inconel-625 space alloy

Inconel-625 is one of the high-strength space alloys with wide applications in aerospace industries and corrosion resistance environments. The applications of Inconel-625 material require blind holes with adequate quality characteristics. In the conventional method, the hole-making on Inconel-625 is difficult due to its mechanical behaviour. The abrasive aqua jet machining process can cut hard and brittle materials among various unconventional machining processes. This work proposes to determine the ideal values of process parameters to generate quality holes on Inconel-625 space alloy by optimizing the abrasive aqua jet hole-making process parameters using a desirability analysis. Abrasive jet pressure (AJP), gap distance (Gdi), traverse speed (Tspeed), and abrasive mixture (Abrmix) of garnet and silicon carbide were identified as potential process variables. The quality hole surface is discussed through surface roughness (SR), erosion rate (Er), circularity error (CI), and cylindricity error (CY). The experimental investigation discloses that SR, CI, and CY decreased by 27.35 %, 56.23 %, and 42.56 %, and Er increased by 32.83 % when the AJP reached its higher value of 300 MPa. According to desirability analysis, the optimal level of machining parameters for numerous solutions is AJP = 300 MPa, Gdi = 1 mm, Tspeed = 96 mm/min, and Abrmix = 100%SiC (AJP-2, Gdi-2, Tspeed-1, Abrmix-2). The ANOVA investigation revealed that AJP was the most contributed parameter, trailed by Abrmix as 100%SiC. SEM and 3D images were used to analyze the surface topography of the hole surface of Inconel-625.

Multi-objective optimization of tool wear, surface roughness, and material removal rate in finishing honing processes using adaptive neural fuzzy inference systems

Honing processes are usually employed to manufacture combustion engine cylinders and hydraulic cylinders. Honing provides a crosshatch pattern that favors the oil flow. In this paper, Adaptive Neural Fuzzy Inference System (ANFIS) models were obtained for tool wear, average roughness Ra, cylindricity and material removal rate in finishing honing processes. In addition, multi-objective optimization with the desirability function method was applied, in order to determine the process parameters that allow minimizing roughness, cylindricity error and tool wear, while maximizing material removal rate. The results showed that grain size and tangential velocity should be at their minimum levels, while density, pressure and linear velocity should be at their maximum levels. If only roughness, cylindricity error and tool wear are considered, then low grain size, low pressure and low linear velocity are recommended, while density and tangential velocity vary, depending on the optimization algorithm employed. This work will help to select appropriate process parameters in finishing honing processes, when roughness, cylindricity error and tool wear are to be minimized.

Study on the influence of journal form and position errors on the lubrication performance of four‐recess capillary restrictor hybrid journal bearing

AbstractIn the actual working condition, due to the manufacturing errors, improper installation, load, thermal deformation or other factors can cause the journal surface to produce the form and position errors. The mathematical models are developed that takes into account the form and position errors, the lubrication performance of four‐recess capillary restrictor hybrid journal bearings with different journal tilt angles and cylindricities is studied, and the effect of eccentricity on the oil film lubrication performance is analysed. The results show that the dimensionless oil film pressure and loading capacity increase as the journal tilt angle and eccentricity increase considering journal tilt, and the friction coefficient tends to increase and then decrease. Compared with journal alignment, the oil film thickness distorts, the oil film pressure peak shifts to the edge of bearing, and the horizontal tilt has a greater impact on bearing when the journal is tilted. The oil film pressure distribution has no significant change considering cylindricity errors, while the oil film pressure value increases, the loading capacity increases and the coefficient of friction decreases as the cylindricity and eccentricity increase. The research shows that the presence of a certain cylindricity error contributes to the lubrication performance of four‐recess capillary restrictor hybrid journal bearings.

Parameters affecting the quality of friction drilled holes and formed thread in austenitic stainless steel AISI 304

The main purpose of this research paper is to improve the quality of the friction-drilled holes and formed thread by investigating the influence of the input working parameters that have not been investigated yet on the quality of the produced bores. Due to lack of research related to the hardness macro- and microstructure of formed threads, experiments were conducted to investigate these important issues. Finally, a tension test was performed to compare the performance of the form tapped thread with the conventionally cut thread. The experiments were conducted on difficult-to-cut material AISI 304 stainless steel workpieces with (2 and 3 mm) wall thicknesses. Tungsten carbide friction drills with diameters (Ø9.2, Ø7.3, and Ø4.5 mm) were used to perform the experiments. The effects of the ratio of workpiece thickness (t) to tool diameter (dT), rotational speed (N), and feed speed (f) on the hole diametral oversize (U), cylindricity error, and collar height were studied. The analysis of variance (ANOVA) showed that the t/d ratio was the most significant factor affecting the mean cylindricity error and the collar height. By comparing the performance of the three tools, it was noticeable that the friction drill Ø7.3 realized better results in terms of mean hole diametral oversize and mean cylindricity error. The elevated temperature associated with high plastic deformation during the processes resulting in fine grains with high hardness values were observed at the heat-affected zone. The longer effective thread length of the formed thread realized higher strength values than the cut thread.Graphical abstract