Surface morphology evaluation of hardened HSLA steel using cryogenic-treated brass wire in WEDM process

2019 ◽  
Vol 104 (9-12) ◽  
pp. 4445-4455 ◽  
Author(s):  
Waseem Tahir ◽  
Mirza Jahanzaib ◽  
Wasim Ahmad ◽  
Salman Hussain
Keyword(s):  
Surface Morphology ◽  
Hsla Steel ◽  
Wedm Process ◽  
Brass Wire

EFFECT OF ELECTRODE MATERIAL ON CUT QUALITIES OF SHAPE MEMORY ALLOY DURING WEDM: A COMPARATIVE STUDY

2019 ◽  
Vol 27 (04) ◽  
pp. 1950136
Author(s):  
HIMADRI MAJUMDER ◽  
KALIPADA MAITY
Keyword(s):  
Micro Hardness ◽  
Process Variables ◽  
Machining Time ◽  
Five Factors ◽  
Series Of Experiments ◽  
Pulse On Time ◽  
Wedm Process ◽  
Different Levels ◽  
Fesem Micrographs ◽  
Brass Wire

This paper compares some of the vigorous machinability characteristics of SMA-Nitinol during WEDM process using uncoated and zinc coated brass wire electrodes. A series of experiments were regulated based on Taguchi’s L[Formula: see text] orthogonal array with an objective of unveiling the benefits of using coated brass wire electrodes in comparison to uncoated counterparts. Five factors, namely pulse-on time ([Formula: see text]), discharge current ([Formula: see text]), wire tension (WT), wire speed (WS) and flushing pressure (FP), were considered, each at three different levels to scrutinize four responses, viz. surface roughness (Ra), kerf width (KW), machining time (MT) and micro-hardness ([Formula: see text]h). It was perceived that zinc-coated brass wire was more preferable to get favorable responses like Ra, KW and [Formula: see text]h when compared with brass wire counterparts. FESEM micrographs also revealed that micro and large cracks, wide craters, recast layer were more prominent on the WEDMed surface of brass wire compared to zinc-coated brass wire. Use of zinc-coated brass wire electrode significantly improves the machinability of the selected work material within the specified range of process variables.

scholarly journals Taguchi Optimization In Machining Inconel 600 With WEDM Process Using Cryogenically Treated Brass Wire

2021 ◽  
Vol 309 ◽  
pp. 01110
Author(s):  
K. Satyanarayana ◽  
B Ramya Krishna ◽  
M. Bhargavi ◽  
R. Eswari Vasuki ◽  
K. Raj Kiran
Keyword(s):  
Surface Roughness ◽  
Metal Removal ◽  
Removal Rate ◽  
Machining Parameters ◽  
Inconel 600 ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Wedm Process ◽  
Off Time ◽  
Brass Wire

Wire electric discharge machining (WEDM) is one amongst the unconventional machining processes which might cut all kinds of shapes with an accuracy of +/−0.001mm. It will cut the materials that conduct electricity and can even cut the exotic metals like tungsten carbide, Hastelloy, Inconel etc. In the present work, machining on Inconel 600 by wire EDM with cryogenically treated brass wire is performed. Brass wire of 0.25mm diameter has been cryogenically treated at −90°C, −100°C and −110°C temperatures separately. An Experimental layout is designed as per Taguchi’s L-9 orthogonal array and experiments were conducted by varying machining parameters viz. Voltage, Pulse ON time and Pulse OFF time. The machining parameters are optimized using Taguchi’s methodology for minimum surface roughness and maximum metal removal rate (MRR). A Mathematical regression model for surface roughness and MRR is generated with the help of regression analysis. Through the Analysis of Variance (ANOVA) It was found that for MRR, pulse on time is the foremost contributing factor with 32.69% and for surface roughness, pulse off time is the foremost contributing factor with 23.59%.

scholarly journals Effect of WEDM Process Parameters on Surface Morphology of Nitinol Shape Memory Alloy

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4943
Author(s):  
Rakesh Chaudhari ◽  
Jay J. Vora ◽  
Vivek Patel ◽  
L. N. López de Lacalle ◽  
D. M. Parikh
Keyword(s):  
Surface Morphology ◽  
Shape Memory ◽  
Surface Analysis ◽  
Process Parameters ◽  
Nickel Titanium ◽  
Machined Surface ◽  
Edx Analysis ◽  
Work Surface ◽  
Wedm Process ◽  
Conventional Machining

Nickel–titanium shape memory alloys (SMAs) have started becoming popular owing to their unique ability to memorize or regain their original shape from the plastically deformed condition by means of heating or magnetic or mechanical loading. Nickel–titanium alloys, commonly known as nitinol, have been widely used in actuators, microelectromechanical system (MEMS) devices, and many other applications, including in the biomedical, aerospace, and automotive fields. However, nitinol is a difficult-to-cut material because of its versatile specific properties such as the shape memory effect, superelasticity, high specific strength, high wear and corrosion resistance, and severe strain hardening. There are several challenges faced when machining nitinol SMA with conventional machining techniques. Noncontact operation of the wire electrical discharge machining (WEDM) process between the tool (wire) and workpiece significantly eliminates the problems of conventional machining processes. The WEDM process consists of multiple input parameters that should be controlled to obtain great surface quality. In this study, the effect of WEDM process parameters on the surface morphology of nitinol SMA was studied using 3D surface analysis, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. 3D surface analysis results indicated a higher value of surface roughness (SR) on the top of the work surface and a lower SR on the bottom portion of the work surface. The surface morphology of the machined sample obtained at optimized parameters showed a reduction in microcracks, micropores, and globules in comparison with the machined surface obtained at a high discharge energy level. EDX analysis indicated a machined surface free of molybdenum (tool electrode).

scholarly journals Milling Microchannels in Monel 400 Alloy by Wire EDM: An Experimental Analysis

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 469 ◽  
Author(s):  
Mustafa Saleh ◽  
Saqib Anwar ◽  
Abdualziz El-Tamimi ◽  
Muneer Khan Mohammed ◽  
Shafiq Ahmad
Keyword(s):  
Surface Morphology ◽  
Electrical Discharge Machining ◽  
Dimensional Accuracy ◽  
Cross Sectional ◽  
Microhardness And Microstructure ◽  
Monel 400 ◽  
The One ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Wedm Process

This paper presents the results of an investigation on the capacity of wire electrical discharge machining (WEDM) to produce microchannels in the Nickel-based alloy, Monel 400. The main objective of the current study is to produce microchannels with desired/target geometry and acceptable surface quality. Square cross-sectional microchannels with dimensions of 500 × 500 µm were investigated. Experiments were conducted based on the one-factor-at-a-time approach for the key input WEDM process parameters, namely pulse-on time (TON), pulse-off time (TOFF), average gap voltage (VGAP), wire feed (WF), and dielectric flow rate (FR). Dimensional accuracy, machining speed, surface roughness, surface morphology, microhardness, and microstructure were analyzed to evaluate the microchannels. The minimum errors of 6% and 3% were observed in the width and depth of the microchannels, respectively. Furthermore, microchannels with enhanced surface integrity could be produced exhibiting smooth surface morphology and shallow recast layer (~0–2.55 µm).

MICROSTRUCTURAL ANALYSIS OF TITANIUM ALLOY GEAR USING WEDM PROCESS

2018 ◽  
Vol 25 (06) ◽  
pp. 1850112
Author(s):  
K. D. MOHAPATRA ◽  
S. K. SAHOO
Keyword(s):  
Titanium Alloy ◽  
Microstructural Analysis ◽  
Machining Process ◽  
Material Surface ◽  
Work Piece ◽  
The Wire ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Wedm Process ◽  
Brass Wire

The present paper deals with the microstructural analysis of Titanium alloy gears (Ti-6Al-4V) by wire EDM process machined by both brass and combii wire electrodes. The objective of the present paper is to investigate the surface characteristics of both the wires and to analyze the effects on the material surface. Two types of wires i.e. brass wire and combii wires were selected for the analysis and the experiment was carried out using a full factorial design having 81 sets of combinations. Pulse on time, pulse off time, wire feed rate and servo voltage were taken as the input parameters and kerf width, material removal rate, surface roughness and wire wear rate were taken as the response parameters for the experiment. The output responses were optimized by using MOORA-based GA methodology. Microstructural analysis was carried out at the optimized settings obtained by two types of wires to investigate the surface defects and analysis present in the work-piece and the wire. The microstructural analysis for the brass wire was investigated depicting the formation of micro cracks, dendrites, spherical globules, melted debris, recast layer and wire rupture on the wire surface after the machining operation. Similarly the microstructural analysis for the combii wire was analyzed out depicting the formation of wire rupture, melted debris, spherical globules, cracks and wire burr formed on the wire after the machining process. The optical image confirms that brass wire has more rupture than the combii wire due to the spark efficiency of brass wire being more than the combii wire. The EDS of material and the wires have been analyzed depicting the presence of element and weight % in the sample. From the performance analysis and the present experiment attained, it was concluded that the combii wire is more desirable to produce high quality gears than the brass wires at the obtained optimized settings of the response.

An Established Epithelial Cell Line (NPC/HK1) from a Nasopharyngeal Carcinoma - II. A Sem Study

1982 ◽  
Vol 40 ◽  
pp. 224-225
Author(s):  
Li C.L. ◽  
Chew E.C. ◽  
Huang D.P. ◽  
Ho H.C. ◽  
Mak L.S. ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Epithelial Cell ◽  
Surface Morphology ◽  
Cell Line ◽  
Epithelial Cell Line ◽  
Present Communication ◽  
Cells In Culture ◽  
Sem Study ◽  
Well Differentiated

An epithelial cell line, NPC/HK1, has recently been successfully established from a nasopharyngeal carcinoma of the moderately to well differentiated squamous type. The present communication reports on the surface morphology of the NPC/HK1 cells in culture.

Specimen Collection Effect in Scanning Electron Microscopy Images

1972 ◽  
Vol 30 ◽  
pp. 448-449
Author(s):  
J. Temple Black ◽  
Jose Guerrero
Keyword(s):  
Surface Morphology ◽  
Secondary Electron Emission ◽  
Secondary Electrons ◽  
Charge Effects ◽  
Material Density ◽  
Specimen Collection ◽  
The Subject ◽  
Curved Paths ◽  
Subject Material ◽  
Microscopy Images

In the SEM, contrast in the image is the result of variations in the volume secondary electron emission and backscatter emission which reaches the detector and serves to intensity modulate the signal for the CRT's. This emission is a function of the accelerating potential, material density, chemistry, crystallography, local charge effects, surface morphology and especially the angle of the incident electron beam with the particular surface site. Aside from the influence of object inclination, the surface morphology is the most important feature In producing contrast. “Specimen collection“ is the name given the shielding of the collector by adjacent parts of the specimen, producing much image contrast. This type of contrast can occur for both secondary and backscatter electrons even though the secondary electrons take curved paths to the detector-collector.Figure 1 demonstrates, in a unique and striking fashion, the specimen collection effect. The subject material here is Armco Iron, 99.85% purity, which was spark machined.

The Effect of Benzene on Bluegill Olfactory Lamellae

1985 ◽  
Vol 43 ◽  
pp. 574-575
Author(s):  
D.R. Mattie ◽  
J.W. Fisher
Keyword(s):  
Surface Morphology ◽  
Soluble Fraction ◽  
Lepomis Macrochirus ◽  
Sublethal Concentration ◽  
Water Soluble ◽  
Major Constituent ◽  
Jet Fuels ◽  
Aquatic Biota ◽  
Normal Surface ◽  
Cacodylate Buffer

Jet fuels such as JP-4 can be introduced into the environment and come in contact with aquatic biota in several ways. Studies in this laboratory have demonstrated JP-4 toxicity to fish. Benzene is the major constituent of the water soluble fraction of JP-4. The normal surface morphology of bluegill olfactory lamellae was examined in conjunction with electrophysiology experiments. There was no information regarding the ultrastructural and physiological responses of the olfactory epithelium of bluegills to acute benzene exposure.The purpose of this investigation was to determine the effects of benzene on the surface morphology of the nasal rosettes of the bluegill sunfish (Lepomis macrochirus). Bluegills were exposed to a sublethal concentration of 7.7±0.2ppm (+S.E.M.) benzene for five, ten or fourteen days. Nasal rosettes were fixed in 2.5% glutaraldehyde and 2.0% paraformaldehyde in 0.1M cacodylate buffer (pH 7.4) containing 1.25mM calcium chloride. Specimens were processed for scanning electron microscopy.

Sign in / Sign up

Export Citation Format

Share Document