Surface Roughness Of Workpiece Research Articles

Development of a new high-shear and low-pressure grinding wheel and its grinding characteristics for Inconel718 alloy

Nickel-based alloy has been widely used due to its outstanding mechanical properties. However, Nickel-based alloy is a typical difficult-to-machine material, which is a great constrain for its application in the manufacturing field. To improve the surface quality of the ground workpiece, a new high-shear and low-pressure grinding wheel, with high ratio of tangential grinding force to normal grinding force, was fabricated for the grinding of selective laser melting (SLM) manufactured Inconel718 alloy. The principle of high-shear and low-pressure grinding process was introduced in detail, which was quite different from the conventional grinding process. The fabrication process of the new grinding wheel was illustrated. A serial of experiments with different processing parameters were carried out to investigate the grinding performance of the developed grinding wheel via analyzing surface roughness and surface morphology of the ground workpiece. The optimal processing parameters of high-shear and low-pressure grinding were obtained. The surface roughness of ground workpiece was reduced to 0.232 μm from the initial value of 0.490 μm under the optimal grinding conditions. It was found that the initial scratches on the ground workpiece were almost completely removed after the observations with the metalloscopy and the field-emission scanning electron microscopy (FE-SEM). The capability of the newly developed high-shear and low-pressure grinding wheel was validated.

Molecular dynamics simulation of ultra-precision machining 3C-SiC assisted by ion implantation

In this paper, molecular dynamics simulations were performed to simulate ion implantation and diamond grinding processes of SiC. Moreover, workpiece surface roughness was predicted based on Rayleigh probability distribution. Effects of ion implantation energy on the temperature, potential energy, cutting force, friction coefficient, and surface morphology of the workpiece during machining were analyzed. It has been revealed that the higher the ion implantation energy, the higher the proportion of internal damage, the lower the temperature rise rate in the workpiece, the lower the cutting force, the smaller the length and number of dislocations, the higher the removal efficiency of single abrasive particles, and the higher the final surface roughness. Among them, the changing trend of surface roughness is qualitative analysis under specific experimental conditions. In conclusion, ion implantation is favorable to SiC processing, and revealing its influence mechanisms has important guiding significance for practical applications.

Research on the relationship between workpiece surface machining quality and turning tool wear

In order to apply the workpiece surface machining quality detection data to tool wear prediction, an experiment on the relationship between workpiece surface machining quality and turning tool wear was carried out. Firstly, the experimental parameters are selected, and the workpiece surface quality is determined as the parameter to study the tool wear law; Secondly, by changing the tool material and workpiece material, the change law of tool wear is analyzed, and the internal reason of blade initial wear is revealed; Finally, the relationship between workpiece surface machining quality and tool wear is analyzed by measuring workpiece surface machining quality parameters. The experimental results show that the relative hardness of workpiece material and tool is the main factor determining the wear speed of tool flank, and the tool geometry is the main factor of rapid tool wear in the initial stage. The workpiece surface roughness increases gradually with tool wear. When the tool enters the severe wear stage, it decreases slightly and then continues to increase. The outer diameter of the workpiece decreases with the tool wear in the initial stage, and then fluctuates and increases gradually. The influence of tool wear on the cylindricity error of shaft parts can be ignored.

Shear Thickening Polishing of Quartz Glass.

Quartz glass is a typical optical material. In this research, colloidal silica (SiO2) and colloidal cerium oxide (CeO2) are used as abrasive grains to polish quartz glass in the shear thickening polishing (STP) process. The STP method employs the shear-thickening mechanism of non-Newtonian power-law fluid to achieve high-efficiency and high-quality polishing. The different performance in material removal and surface roughness between SiO2 and CeO2 slurries was analyzed. The influence of the main factors including polishing speed, abrasive concentration, and pH value on the MRR, workpiece surface roughness, and the surface topography was discussed. Two different slurries can both achieve fine quartz surface in shear thickening polishing with the polishing speed 100 rpm, and pH value 8. The quartz glass surface roughness Ra decreases from 120 ± 10 to 2.3 nm in 14 minutes’ polishing with 8 wt% 80 nm SiO2 slurry, and the MRR reaches 121.6 nm/min. The quartz glass surface roughness Ra decreases from 120 ± 10 to 2.1 nm in 12 minutes polishing by 6 wt% 100 nm CeO2 slurry and the MRR reaches 126.2 nm/min.

Machining of hard materials using textured tool with minimum quantity nano-green cutting fluid

Metal cutting causes severe friction and heat generation in the machining zone. Previously, petroleum-based cutting fluids were applied for reducing friction and machining temperature at the machining zone. Nowadays, nano-cutting fluids are preferred owing to their higher thermal conductivity and better lubricating ability. However, during machining of hard materials (hardness, ≥50 HRC), the effectiveness of these nano-cutting fluids is limited, as they rarely reach to the cutting edge of cutting tool because of high normal stresses. In this regard, the combination of rake face micro-textured cutting tool with indigenously synthesized nano-green cutting fluids under in-house developed minimum quantity cutting fluid (MQCF) environment is accomplished for hard machining experiments. For comparison, hard machining experiments are also performed under dry machining, green cutting fluid and nano-green cutting fluid (NGCF) with untextured cutting tools. Detailed analysis shows significant improvement in hard machining performance using combination of micro-textured tools with NGCF corresponding to forces, chip-tool interface friction, workpiece surface roughness and chip morphology. It is attributed to better infiltration of NGCF in-between chip-tool interface by virtue of micro-textures present on the cutting tool rake face. Further, the proposed analytical model captures the effect of textures on the tool surface in the same way as reduced contact tools. It is in a good agreement with corresponding experimental cutting forces.

Analyzing the Vibration Effect of Cutting Tool on Surface Roughness of Turning Work Piece in Lathe Machine

Tool condition observation systems area unit essential in small milling applications. A tool's slenderness needs high-precision observation systems for on-line measurements. In most cases, tool health is indirectly calculable by process and analyzing the cutting method parameters cutlery wear may be a essential development that influences the standard of the machined half. Vibration signals from metal cutting processes are investigated for varied functions, together with in-process tool wear monitoring. Reducing the machining energy consumption (MEC) of machine tools for turning operations is important to market manufacturing producing. during this study, the link between vibration and gear wear is investigated throughout high-speed dry turning by victimization applied math parameters. it's aimed to show however tool wear and therefore the work piece surface roughness changes with tool vibration signals. For this purpose, a series of experiments were conducted in a lathe machine. Modal analysis of each traditional and wear cutlery are going to be perform for locating Natural frequency of cutting tools in ANSYS 19 code. Experimental testing of cutlery are going to be perform using FFT instrument. afterward the comparative analysis are going to be dispensed between the experimental and analysis results and afterward the result & conclusion are going to be drawn.

EXPERIMENTAL INVESTIGATION AND OPTIMIZATION OF HIGH SPEED MACHINING OF TITANIUM ALLOY FOR BIOMEDICAL APPLICATION

The Ti-6Al-4V alloy is known as materials with high hardness and good mechanical properties. However, the machining process of this material faces many difficulties due to unfavorable machining conditions. When the machining parameters are not selected in accordance with the Ti-6Al-4V alloy, the surface quality of workpieces does not meet technical requirements. Therefore, the appropriate machining parameters are needed to upgrade the surface roughness of workpieces in high-speed machining (HSM) conditions. The main cutting forces Py and Pz, and surface roughness Rz during turning of Ti-6Al-4V alloy in HSM were investigated and evaluated in this study. The response surface method (RSM) was used to conduct experiments and establish the models of Rz, Py, and Pz under various cutting conditions of feed rate ([Formula: see text]), tool nose radius ([Formula: see text]), and approach angle ([Formula: see text]). As a result, the [Formula: see text] value has the largest impact on the Pz. Moreover, the machining parameters such as [Formula: see text], [Formula: see text], and [Formula: see text] have a great influence on the Py. The magnitude of Rz is mainly affected by [Formula: see text] value. Based on the optimal parameters, the average value of the force Pz has decreased from 238[Formula: see text]N to 169[Formula: see text]N, corresponding reduction of about 29%. The value of the force Py has reduced from 184[Formula: see text]N to 118[Formula: see text]N, corresponding reduction of about 36%. In addition, the surface roughness of the workpiece has been improved significantly from Rz of 5.6[Formula: see text][Formula: see text]m to 2.7[Formula: see text][Formula: see text]m under optimal parameters condition. The surface roughness of the workpiece after processing in high speed machining was reduced of 52% compared with cutting under non-optimal parameters condition. The best surface quality and minimum cutting force could be achieved under optimal processing parameters in high speed cutting method.

Study the Effect of Inductor and Pole Geometry on the Surface Roughness and Material Removal Weight Using Magnetic Abrasive Finishing Method

The traditional finishing method cannot keep up with recent labor market requirements, solve the problem of increasing production, improve the surface roughness and accuracy of workpiece. While the unconventional magnetic abrasive finishing (MAF) method has shown as a promising technique that can be used to finish complicated surfaces. MAF finishes metals, alloy, ceramic, and other materials that are difficult to finish by other processes. In another word, MAF improves the quality of surfaces with low cost.
 This paper focuses on optimize and study the effect of inductor and pole geometry (radius of hole, angle of core, angle of pole, radius of pole), on (surface roughness (Ra) and material removal weight (W)) and fined the optimum values that increase the efficiency of MAF method. Taguchi method employed to study the influence of geometry parameters and find the optimum values using orthogonal array L9. The results conclude that the most significant factor that effects change in surface roughness (ΔRa) and material removal weight(ΔW) are radius of the hole (R) and angle of core (α), respectively.

Product Quality Prediction for Wire Electrical Discharge Machining with Markov Transition Fields and Convolutional Long Short-Term Memory Neural Networks

This paper proposes a wire electrical discharge machining (WEDM) product quality prediction method, called MTF-CLSTM, to integrate the Markov transition field (MTF) and the convolutional long short-term memory (CLSTM) neural network. The proposed MTF-CLSTM method can accurately predict WEDM workpiece surface roughness right after manufacturing by collecting and analyzing static machining parameters and dynamic manufacturing conditions. The highly accurate prediction is due to the following two reasons. First, MTF can transform data into images to extract data temporal information and state transition probability information. Second, the CLSTM neural network can extract image spacial features and temporal relationship of data that are separated far apart. In short, MTF-CLSTM predicts WEDM workpiece surface roughness with the MTF model and the CLSTM neural network using static machining parameters and dynamic manufacturing conditions. MTF-CLSTM is compared with 10 related research studies in many aspects. There is only one existing method that is like MTF-CLSTM to predict WEDM workpiece surface roughness by using static machining parameters and dynamic manufacturing conditions. Experiments are conducted to evaluate MTF-CLSTM performance to show that MTF-CLSTM significantly outperforms the existing method in terms of the prediction mean absolute percentage error.

Effects of tool rake angle and workpiece surface roughness on nanocutting of cu investigated using Multiscale simulation

ABSTRACT The effects of tool rake angle and workpiece surface roughness on the cutting mechanism and mechanics of Cu are studied using quasi-continuum simulations. These effects are investigated in terms of atomic trajectories, stress distribution, cutting force, resistance factor, and cutting ratio. The simulation results show that negative rake angles lead to a larger cutting force, lower resistance coefficient, and higher cutting ratio than those obtained with positive rake angles. For tools with an initial rake angle of 2° to 8°, the rake angle becomes negative during the cutting process due to the strong adhesion interaction between the tool rake face and chips. The resistance coefficient decreases with increasing tool rake angle for rake angles in the range of 2° to 8°. Tools with negative rake angles of −2° to −8° have similar cutting ratios. The cutting ratio decreases and cutting force increases with increasing surface roughness of the workpiece.

Study of the tool path generation method for an ultra-precision spherical complex surface based on a five-axis machine tool

The improvement of ultra-precision machining technology has significantly boosted the demand for the surface quality and surface accuracy of the workpieces to be machined. However, the geometric shapes of workpiece surfaces cannot be adequately manufactured with simple plane, cylindrical, or spherical surfaces because of their different applications in various fields. In this research, a method was proposed to generate tool paths for the machining of complex spherical surfaces based on an ultra-precise five-axis turning and milling machine with a C-Y-Z-X-B structure. Through the proposed tool path generation method, ultra-precise complex spherical surface machining was achieved. First, the complex spherical surface model was modeled and calculated, and then it was combined with the designed model to generate the tool path. Then the tool paths were generated with a numerically controlled (NC) program. Based on an ultra-precision three-coordinate measuring instrument and a white light interferometer, the machining accuracy of a workpiece surface was characterized, and the effectiveness of the tool path generation method was verified. The surface roughness of the machined workpiece was less than 90 nm. Furthermore, the surface roughness within the spherical region appeared to be less than 30 nm. The presented tool path generation method in this research produced ultra-precision spherical complex surfaces. The method could be applied to complex spherical surfaces with other characteristics.

Optimization of Machining Parameters in Hard Turning of Automotive Gears with PCBN tool using Taguchi Method

Hard turning, a comparatively modern machining technology, can replace the conventional grinding process for finishing of parts made out of steel. Nowadays, industries prefer hard turning to grinding. This is due to some of the most distinctive features of hard turning over grinding, such as lower machining time and manufacturing cost, and the achievement of grinding equivalent quality characteristics on parts and machining can be possible in a dry environment, which eliminates the hazardous effect of cooling media used during machining on the environment and humans. However, in hard turning, machining parameters (cutting speed-vc, depth of cut-ap, and feed rate-f) are critical for achieving specified quality attributes and establishing a cost-effective setup. The influence of machining parameters on workpiece surface roughness (Ra) and tool flank wear (VB) has been investigated in this research using the Taguchi Design of Experiment (DOE) approach, as well as signal to noise (S/N) ratio, and Analysis of variance (ANOVA) techniques. The experiments have been carried out on automotive gear made of SAE-AISI 5120-compliant 20Mn5Cr5 alloyed hardened steel. The CBN cutting tool has been used for this research.

An Experimental and Finite Element Approach for a Better Understanding of Ti-6Al-4V Behavior When Machining under Cryogenic Environment.

Due to increasing demand in manufacturing industries, process optimization has become a major area of focus for researchers. This research optimizes the cryogenic machining of aerospace titanium alloy Ti-6Al-4V for industrial applications by studying the effect of varying the nozzle position using two parameters: the nozzle’s separation distance from the tool–chip interface and its inclination angle with respect to the tool rake face. A finite element model (FEM) and computational fluid dynamics (CFD) model are used to simulate the cryogenic impingement of cryogenic carbon dioxide on the tool–workpiece geometry. Experiments are conducted to evaluate cutting forces, tool wear, and surface roughness of the workpiece, and the results are related to the CFD and FEM analyses. The nozzle location is shown to have a significant impact on the cutting temperatures and forces, reducing them by up to 45% and 46%, respectively, while the dominant parameter affecting the results is shown to be the separation distance. Cryogenic machining is shown to decrease adhesion-diffusion wear as well as macroscopic brittle chipping of the cutting insert compared to dry turning, while the workpiece surface roughness is found to decrease by 44% in the case of cryogenic machining.

Optimization of CNC Milling Parameters for Complex 3D Surfaces of SIMOLD 2083 Alloy Mold Core Utilizing Multiobjective Water Cycle Algorithm

In this article, an effective multiobjective optimization approach is exploited to search for the best milling parameters for CNC for complex 3d surfaces of SIMOLD 2083 alloy mold core. To improve the quality responses, the cutting factors are optimized by a combination of Taguchi method (TM), response surface method (RSM), and multiobjective water cycle algorithm (MWCA). Firstly, the design for initial series experiments of the cutting factors was generated via the TM. Thereafter, the regression models between the cutting factors and the surface roughness of the machined workpiece surface as well as milling time are formed via applying the RSM. Moreover, analysis of variance and sensitivity analysis are also executed to define the influences and crucial contributions of cutting parameters on the surface roughness and milling time. The results of analysis of variance showed that the factors which have main effects on surface roughness were spindle speed (42.42%), feed rate (29.40%), and cutting depth (6.59%), respectively. Meanwhile, the feed rate with the influence of 92.6% was the most significant factor in controlling the milling time. Ultimately, based on mathematical models, the MWCA is performed to define the optimal factors. The optimal results indicated that the optimized surface roughness was about 0.260 μm and the milling time was roughly 1012.767 (s). In addition, the errors between forecasted results and experimental verifications for the surface roughness and milling time are 2.04% and 5.39%, respectively. Therefore, the results of experimental verifications are suitable with the forecasted results from the proposed optimization method. These results depicted that the proposed integration approach can define effectively the optimal cutting factors for CNC milling and expand to apply for complex multiobjective optimization problems.

Micro-milling mechanism and surface roughness of high volume fraction SiCp/Al composites

In this paper, a finite element simulation model of diamond tool milling SiCp/Al composites was established. The cutting stress, stress distribution and material removal mechanism of the SiC-reinforced material were studied. At the same time, the correctness of the finite element simulation was verified by a micro-milling experiment. The results show that the main particle removal methods include pulling out, crushing and pressing in and that the particle removal methods are different when the tool is cutting at different positions. With increasing cutting speed, the surface defects of the material are reduced and the surface quality is improved. The main surface defects in the milling process are voids, microcracks, scratches and pits. Through the optimization of cutting parameters, it is found that the milling depth has the greatest effect on the surface roughness, the spindle speed has the second greatest effect, and the feed rate has the least effect. The surface roughness of the machined workpiece is 0.238 μm when the process parameters have been optimized.

Feasibility Study on the Precision Polishing of Zirconia Ceramics with Magnetic Compound Fluid (MCF) Slurry Under the Assistance of Dielectrophoresis Effect

In this work, a new polishing method for zirconia ceramics was firstly proposed, which combined dielec-trophoresis effect with magnetic compound fluid polishing. A key experimental device was designed and constructed, and the influence behavior of dielectrophoresis phenomenon on the polishing efficiency, surface roughness and glossiness of zirconia ceramic workpiece were investigated. Also, the effects of voltage, electrode shape and electric field parameters on the polishing results were deeply discussed. The results showed that when the magnetic field was stronger, the polishing efficiency would become higher, while the surface quality of the workpiece getting worse. And the glossiness was positively correlated with the surface roughness. Moreover, the smaller the electrode shape and the larger the electric field gradient caused the better dielectrophoresis-assisted effect. It was indicated that when the electrode shape was a circle with a diameter of 20 mm and the voltage was 1500 V, the material removal efficiency was improved by 36.4% while ensuring the surface quality of zirconia ceramics.

Modeling of the Cutting Force and Workpiece Surface Roughness During the Milling Process with High Feed Using Artificial Neural Networks

Modeling of the Cutting Force and Workpiece Surface Roughness During the Milling Process with High Feed Using Artificial Neural Networks

Exploring the feasibility of novel coated wires in wire EDM of Ti-6Al-4 V aerospace alloy: a case of multi-pass strategy

Wire electric discharge machining (WEDM) is a thermoelectrical process wherein workpiece surface integrity still remains a concern due to process-generated thermal damage. Recent developments in WEDM, such as the use of novel coated wires and multi-pass strategy, present opportunity for reducing this thermal damage and improve surface integrity. Available literature shows that only uncoated wires have been used with multi-pass cutting strategy. Present work reports on the integrated benefits of coated wires with multi-pass cutting technique while employing three coated wires, namely brass core Zn coated, Broncocut Type X (Cu core-ZnCu50 coating) and Topas Plus X (Cu core-double Zn-rich layer coating), to machine superalloy Ti-6Al-4 V in view of its extensive aerospace applications. Five output responses involving workpiece surface roughness, over cut, cutting speed, material removal rate and recast layer thickness have been assessed. Each experiment constituted one rough pass followed by two trim cuts with each cut taken at offset/input parametric settings appropriate for the individual cut type. For comparison purposes, baseline experiment was conducted with uncoated brass wire using the same input parameters employed for rough and rough plus trim cuts for other coated wires considering the fact that rough cut is intended for high material removal, while trim cuts focusing on better surface integrity. Results show that Topas Plus X wire outperformed other wire types investigated in this work. Up to 8% reduction in Ra value, up to 31% increase in cutting speed, up to 26% higher material removal rate (in rough cut) and up to 40% lesser recast layer thickness have been obtained with Topas X wire. Though coated wires resulted in much better performance otherwise, however, higher “overcut” was observed for all coated wires when compared with the simple brass wire. Also, trim cuts that succeeded the rough passes produced crack-free surfaces.

Influence of turning tool wear on the surface integrity and anti-fatigue behavior of Ti1023

Titanium alloy Ti1023 is a typical difficult-to-cut material. Tool wear is easy to occur in machining Ti1023, which has a significant negative effect on surface integrity. Turning is one of the common methods to machine Ti1023 parts and machined surface integrity has a direct influence on the fatigue life of parts. To control surface integrity and improve anti-fatigue behavior of Ti1023 parts, it has an important significance to study the influence of tool wear on the surface integrity and fatigue life of Ti1023 in turning. Therefore, the effect of tool wear on the surface roughness, microhardness, residual stress, and plastic deformation layer of Ti1023 workpieces by turning and low-cycle fatigue tests were studied. Meanwhile, the influence mechanism of surface integrity on anti-fatigue behavior also was analyzed. The experimental results show that the change of surface roughness caused by worn tools has the most influence on anti-fatigue behavior when the tool wear VB is from 0.05 to 0.25 mm. On the other hand, the plastic deformation layer on the machined surface could properly improve the anti-fatigue behavior of specimens that were proved in the experiments. However, the higher surface roughness and significant surface defects on surface machined utilizing the worn tool with VB = 0.30 mm, which leads the anti-fatigue behavior of specimens to decrease sharply. Therefore, to ensure the anti-fatigue behavior of parts, the value of turning tool wear VB must be rigorously controlled under 0.30 mm during finishing machining of titanium alloy Ti1023.

Defect-free high-feed milling of Ti-6Al-4V alloy via a combination of cutting and wiper inserts

Ti-6Al-4V alloy machining is challenging due to inherent properties. Wiper inserts improve the surface finish at higher feed rates because of multi-radii geometry. Wiper inserts when combined with the cutting inserts can provide smooth surface finish. The current work is aimed to study the influence of cutting and wiper inserts in Ti-6Al-4V alloy milling while considering wear scar of tool/life, surface roughness, surface topography, micro-hardness, and microstructural evaluations as output responses under higher levels of feed rates in dry machining. The combination of cutting insert along with wiper geometry provides machining innovation due to the fact that good surface finish can be achieved in a single step. Three levels of feed rate (f) (1.2, 1.4, 1.6 mm/revolution) along with three levels of depth of cut (ap) (0.25, 0.40, 0.50 mm) were employed for the experimentation. The variation in workpiece surface roughness (Ra) was found in between 0.3 and 0.71 μm-Ra. Surface topography analysis under the scanning electron microscope (SEM) of the machined specimen revealed no voids/cracks; however, scratch marks/welding of microchips were noticed. No alteration in microstructure was found when milling at 1.2 and 1.4 mm/revolution feed rate. A white layer deepened to 18 μm from the milled surface was seen at a feed rate of 1.6 mm/revolution. In addition, approximately 15% increase in micro-hardness was observed beneath the milled surface when evaluated machining variables were at their peak levels, i.e., at 1.6 mm/revolution and 0.5 mm respectively, while only 5.4% increase in the said response was observed at f of 1.2 mm/revolution.