Experimental Investigation of Electrochemical Micro Turning of Ti6Al4V With NaOH Solution

Author(s):  
Arnab Das ◽  
Deepak Kumar ◽  
Mohan Kumar ◽  
Vivek Bajpai

Abstract Ti6Al4V is a highly favorable material in biomedical, aerospace and many other industries. However, rapid tool wear during machining has made Ti6Al4V into a difficult-to-machine material. Electrochemical machining may be a solution to that challenge. Moreover, high chemical affinity and formation of oxide layer over the surface have limited the application electrochemical machining for Ti6Al4V. In this paper, an experimental approach of electrochemical micro turning of Ti6Al4V has been described. The electrolyte was 10% aqueous solution of NaOH and the tool was SS 310. For each and every experiment workpiece rotational speed and machining time were kept constant. Constant DC voltage was applied and the inter-electrode gap between tool and workpiece was kept constant for each experiment. Experiments were performed using two different levels of applied voltage, axial feed rate and inter-electrode gap. Their effects over MRR and surface roughness have been determined. Additionally, the optimum working condition was determined in order to maximize MRR and minimize surface roughness. For each experiment, acceptable material removal and good surface finish have been achieved. The maximum surface roughness (Ra) was found 1.128 μm in experiment 1. The utilization of NaOH solution has resulted in controlled electrolyzing current, controlled material removal and therefore, good surface finish.

2011 ◽  
Vol 291-294 ◽  
pp. 810-815 ◽  
Author(s):  
Qi Wu ◽  
Jun Wang

An experimental study of the pulsed laser milling process for a sintered polycrystalline diamond is presented. The characteristics and quality of the cavities machined with a Yd laser under different pulse energies, pulse overlaps, scan overlaps and numbers of passes are discussed, together with the effects of these parameters on the cavity profile, depth of cut and surface roughness. A statistical analysis is also presented to study the relationship between the process parameters and surface roughness. It shows that the optimum pulse overlap and pulse energy may be used to achieve good surface finish, whereas scan overlap and number of passes can be selected to improve the depth of cut without much effect on the surface finish.


2016 ◽  
Vol 874 ◽  
pp. 158-166
Author(s):  
Run Chen ◽  
Jia Bin Lu ◽  
Qiu Sheng Yan ◽  
Xiao Lan Xiao ◽  
De Yuan Li

The polishing experiments of anodic oxide film of aluminum were performed to research the influence of polishing parameters on the surface roughness and material removal rate in the cluster magnetorheological finishing (MRF). Experimental results demonstrate that a mirror effect can be reached when the anodic oxide film of aluminum is polished by the Cluster MRF. The roughness of the workpiece surface after polishing for 15 min is decreased from Ra 0.575μm to Ra 4.13nm and the material removal rate is 0.653mg/min. With the extension of the polishing time, the surface roughness rapidly declines at first and then slowly decreases. When the machining time is more than 15min, the anodic oxide film of aluminum is easily worn out, resulting in a sharp increase in the surface roughness. The machining gap between the workpiece and the polishing plate influences the polishing effect of anodic oxide film of aluminum. With the increase of the machining gap, the material removal rate decreases and the surface roughness increases. A good surface quality can be got at the machining gap of 1.1mm. The type and size of abrasive particles will directly affect the polishing effect of anodic oxide film of aluminum, and when using CeO2 abrasive with the particle size of W3, a higher material removal rate and a smaller surface roughness can be obtained.


2015 ◽  
Vol 766-767 ◽  
pp. 674-680
Author(s):  
P. Karunakaran ◽  
J. Arun ◽  
V. Palanisamy ◽  
N.R.R. Anbusagar ◽  
P. Sengottuvel

Improving the Material Removal Rate (MRR), reduce Tool Wear Rate (TWR), achieve the good Surface Finish (SF) and Over Cut (OC) are very demanding in Electrical Discharging Machining (EDM). This paper focused on performance of Silicon powder mixed with kerosene servotherm dielectric medium in EDM of Monel 400. The optimum range of Silicon powder, Graphite powder 6g mixes with the dielectric medium of kerosene servotherm (75:25) were developed experimentally. It was reported slightly more MRR, very low TWR, better OC and good surface finish (SF) in Monel 400.


Author(s):  
Nguyen Thi Bich Nhung ◽  
Dao Thanh Liem ◽  
Truong Quoc Thanh

Based on the number of previous studies, this study aims to investigate the effects of process parameters of an Electrochemical Machining process, which are electrolyte concentration, the voltage applied to the machine, feed rate of the electrode, and Inter-Electrode Gap between tool and workpiece. Aluminum samples of 25 mm diameter x 25 mm height and 30mm diameter x 25mm height of the tool is made up of copper with a circular cross-section with 2 mm internal hole. The design of the system is based on the Taguchi method. Here, the signal-to-noise (S/N) model, the analysis of variance (ANOVA) and regression analyses are applied to determine optimal levels and to investigate the effects of these parameters on surface quality. Finally, the experiments that use the optimal levels of machining parameters are conducted to verify the effects of the process parameters on the surface quality of the products. The results pointed out a set of optimal parameters of the ECM process. The Inter-Electrode Gap between the tool and workpiece has extremely effected on these Material Removal rates and surface roughness. The Material Removal Rate increases with diseases in Inter-Electrode Gap, and Ra diseases with diseases in Inter-Electrode Gap. The experimental results show that maximum Material Removal Rate has obtained with electrolyte concentration at 100 g/l, feed rate at 0.0375 mm/min, the voltage at 15V, and Inter-Electrode Gap at 0.5mm. The minimum Ra has obtained with electrolyte concentration at 80 g/l, feed rate at 0.0468 mm/min, the voltage at 10V, and Inter-Electrode Gap at 0.5mm. This result has led to need studies on these parameters in Electrochemical Machining, which are improving productivities and surface roughness of the products.   


2021 ◽  
Vol 06 ◽  
Author(s):  
Irfan Ahmad Ansari ◽  
Dipti Sharma ◽  
Kamal K. Kar ◽  
Janakarajan Ramkumar

The good surface finish of gears is one of the critical parameters which leads to its noise-free operation, efficient power transmission, and longer service life. However, most of the gear manufacturing processes do not produce a good surface finish. Therefore, gears need post-processing to finish their surface. Out of several methods of gear finishing like gear grinding, lapping, and honing, the abrasive flow finishing process offers more flexibility due to its self-deformable abrasive medium which can easily flow across complex internal or external geometry. The present study aims to improve the surface finish of helical gear by abrasive flow finishing (AFF) by experimentally identifying the optimum range of the potential input process parameters. An AFF set up was used for gear finishing by using a medium of styrene-butadiene and soft silicone polymer, Silicon carbide abrasive, and silicone oil as a blending agent. A special fixture was developed comprising of five parts namely spider, mandrel, upper, middle, and bottom cylinder with a circumferential hole, which allows the back and forth movement of AFF medium through the annular volume between fixture and gear. Further, an experimental investigation of process parameters like viscosity, effect of percentage of various components in medium, operating pressure, and helix angle of helical gears have been studied on percentage improvement of surface roughness (Ra) value of the gear. It is found that the concentration of abrasives in media and extrusion pressure were the two most significant parameters that have a maximum effect on the percentage reduction in surface roughness and finishing rate. Results show that the optimum combination of the extrusion pressure and abrasive weight percentage is 38 bar and 40 % that produces best results of around 76 and 69 % improvement in Ra for gear of helix angle 30 degree and 45 degree respectively.


2005 ◽  
Vol 20 (2) ◽  
pp. 504-520 ◽  
Author(s):  
Honglin Zhu ◽  
Dale E. Niesz ◽  
Victor A. Greenhut ◽  
Robert Sabia

A series of abrasives with various hardness values including monocrystalline and polycrystalline diamond, α- and γ-alumina, zirconia, ceria, and silica were used to examine the concept of chemical-assisted polishing for finishing the (0001), c-plane (basal plane), of sapphire. Diaspore, a monohydrate of alumina, was also evaluated. Atomic force microscopy suggested that the hydrated layer of the c-plane surface was about 1 nm thick. Polishing experiments were designed to determine whether the chemically modified surface hydration layer forms on the basal plane in water. The results indicate that harder abrasives do not necessarily cause faster material removal and better surface finish for similar abrasive particle size. Abrasives with hardness equal to or less than sapphire such as α-Al2O3 and γ-Al2O3 achieved the best surface finish and greatest efficiency of material removal. It is proposed that the (0001) c-plane sapphire surface was modified by water to form a thin hydration layer with structure and hardness close to diaspore. This reaction layer can be removed by an abrasive that is softer than sapphire but harder than the reaction layer. α-Al2O3 was particularly effective. This result is attributed to adhesion between identical reaction layers on the basal planes of the alumina abrasive and the sapphire. This demonstrates that high removal rates and good surface finish can be achieved without costly diamond polishing.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
A. Bovas Herbert Bejaxhin ◽  
G.M. Balamurugan ◽  
S.M. Sivagami ◽  
K. Ramkumar ◽  
V. Vijayan ◽  
...  

Dual heat treatment (DHT) effect is analyzed using the machining of Al6061-T6 alloy, a readily available material for quickly finding the machining properties. The heat treatments are conducted twice over the specimen by the furnace heating before processing through CNC machining. The HSS and WC milling cutters are preferred for the diameter of 10 mm for the reviewed rotational speeds of 2000 rpm and 4000 rpm, and the constant depth of cut of 0.5 mm is chosen based on various reviews. Worthy roughness could be provided mostly by the influence of feed rates preferred here as 0.05 mm/rev and 0.1 mm/rev. The influencing factors are identified by the Taguchi, genetic algorithm (GA), and Artificial Neural Network (ANN) techniques and compared within it. The simulation finding also helps to clarify the relationship between influenced machining constraints and roughness outcomes of this project. The average values of heat treated and nonheat treated Al6061-T6 are compared and it is to be evaluated that 41% improvement is obtained with the lower surface roughness of 1.78975 µm and it shows good surface finish with the help of dual heat treatment process.


2021 ◽  
Author(s):  
Sonia Ezeddini ◽  
Wajdi Rajhi ◽  
Mohamed Boujelbene ◽  
Emin Bayraktar ◽  
Sahbi Ben Salem

Abstract Ti-6242 is a super alloy which exhibits the best creep resistance among available titanium alloys and is widely used in the manufacture by WEDM of aircraft engine turbomachinery components. However, the final quality of wire EDMed surface is a great challenge as it is affected by various factors that need optimization for surface integrity and machine efficiency improvement. The aim of this study is to investigate the effect of a set of cutting process parameters such as pulse on time (Ton), servo voltage (U), feed rate (S) and flushing pressure (p) on surface roughness (SR) when machining Ti-6242 super alloy by WEDM process using a brass tool electrode and deionized water as a dielectric fluid. WEDM experiments were conducted, and SR (Ra) measurement was carried out using a 3D optical surface roughness-meter (3D–SurfaScan). As a tool to optimize cutting parameters for SR improvement, Taguchi's signal‐to‐noise ratio (S/N) approach was applied using L9 (3^4) orthogonal array and Lower-The-Better (LTB) criteria. Substantially, the findings from current investigation suggest the application of the values 0.9 µs, 100V, 29 mm/min, and 60 bar for Ton, U, S and p cutting parameters, respectively, for producing a good surface finish quality. Percent contributions of the machining parameters on SR (Ra) assessed based on ANOVA analysis are 62.94%, 20.84%, 11.46% and 4.74% for U, S, Ton and p, respectively. Subsequently, accurate predictive model for SR (Ra) is established based on response surface analysis (RSA). The contour plots for SR (Ra) indicate that when flushing pressure p converges to a critical value (80 bar), a poor-quality surface finish is highly expected with the excessive increase in U and S. Electron microscope scanning (SEM) observations have been performed on machined surface for a wide range of cutting parameters to characterize wire EDMed surface of Ti-6242. SEM micrographs indicate that the machined surface acquires a foamy structure and shows white layer and machining-induced damage that the characteristics are highly dependent on cutting parameters. At high servo-voltage, the decrease in pulse on time Ton and feed rate S results in a large decrease in overall machining-induced surface damage. Moreover, for high servo-voltage and feed rate levels, it has been observed that pulse on time could play a role of controlling the surface microcracks density. In fact, the use of a low pulse duration of cut combined with high servo-voltage and feed rate has been shown to inhibit surface microcracks formation giving the material surface a better resistance to cracking than at high pulse duration.


Author(s):  
Hui-Qun Chen ◽  
Qing-Hui Wang

Based on the Z-map model of a workpiece and the dynamic cutting forces model of peripheral milling in which the regenerative effect of tool radial runout and axial drift are considered, a model for the prediction of surface topography in peripheral milling operations is presented. According to the stability lobe diagram obtained by the zero-order analytical method, the relationship between spindle speed and surface topography, the tool radial runout, and the axial drift following the chatter are studied. The results show that a stable cutting status but a poor surface finish is obtained at the spindle speeds at which the dominant frequency of the milling system is integral multiples of the selected machining frequency, and a stable cutting status with a good surface finish can be obtained near and on the left side of the resonant spindle speeds determined by the predicted stability lobe diagram. The motion equations of any tooth end mill for peripheral milling are established, and these equations are based on the transformation matrix and the vector operation principle of motion-homogeneous coordinates. In addition, the simulation algorithm and the system of surface topography generated in peripheral milling are given based on the Z-map model. Cutting tests are carried out, and good agreement between the measured surface topographies and the topographies predicted by the model in this study is found in terms of their shape, magnitude, feed mark, profile height of cross-section, and surface roughness. The simulation results show that the milling surface roughness increases with the increase in feed per tooth, which further shows that this simulation system has high credibility. Thus, the simulation and experimental results can provide some practical instructions for the actual peripheral milling in determining the optimal machining conditions.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3505
Author(s):  
Basem M. A. Abdo ◽  
Syed Hammad Mian ◽  
Abdualziz El-Tamimi ◽  
Hisham Alkhalefah ◽  
Khaja Moiduddin

Micromachining has gained considerable interest across a wide range of applications. It ensures the production of microfeatures such as microchannels, micropockets, etc. Typically, the manufacturing of microchannels in bioceramics is a demanding task. The ubiquitous technologies, laser beam machining (LBM) and rotary ultrasonic machining (RUM), have tremendous potential. However, again, these machining methods do have inherent problems. LBM has issues concerning thermal damage, high surface roughness, and vulnerable dimensional accuracy. Likewise, RUM is associated with high machining costs and low material-removal rates. To overcome their limits, a synthesis of LBM and RUM processes known as laser rotary ultrasonic machining (LRUM) has been conceived. The bioceramic known as biolox forte was utilized in this investigation. The approach encompasses the exploratory study of the effects of fundamental input process parameters of LBM and RUM on the surface quality, machining time, and dimensional accuracy of the manufactured microchannels. The performance of LRUM was analyzed and the mechanism of LRUM tool wear was also investigated. The results revealed that the surface roughness, depth error, and width error is decreased by 88%, 70%, and 80% respectively in the LRUM process. Moreover, the machining time of LRUM is reduced by 85%.


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