Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Surface Roughness


Experimental Investigation of Wire EDM Process Parameters on Heat Affected Zone

V.N. Najm

Engineering and Technology Journal, 2018, Volume 36, Issue 1, Pages 46-54

It is vital to study the impact of heat since it has an unwanted phenomenon on the operating life of parts produced, which is in turn effect the cost of production. when dimension accuracy is the primary function Wire cut machining comprehensively used specially when machining hard metal by using precisely controlled sparks that occur between a very thin wire and a workpiece in the presence of a dielectric fluid. The aim of this research is to study the effects of some Wire Electrical Discharge Machining (WEDM) variables on heat affected zone, white layer and Surface Roughness (SR) of high speed steel using ANOVA method to analyze the behavior of control parameters such as pulse on time (μs), current and wire tension. Experimental investigations separates into two main parts in the first one the wire electrical discharge machining process was accomplished on smart EDM (Electra wire cut machine), and in the second part the roughness of the machined samples surface was tested and the samples were prepared to be measured. The results shows that the heat affected zone and the white layer are affected with the risen of the current and pulse on time values more than the risen in wire tension values, as well as the wire tension affects the surface roughness more than the current and pulse on time.

Prediction of Surface Roughness and Material Removal Rate for 7024 AL-Alloy in EDM Process

Abbas Fadhil Ibrahim; Mostafa Adel Abdullah; Safaa Kadhim Ghazi

Engineering and Technology Journal, 2016, Volume 34, Issue 15, Pages 2796-2804

This paper studies prediction the values of MRR and surface roughness in Electrical discharge operations. It is a operation in which the material removal rate is machined with elevation spark in the midst work piece and electrode sunken through dielectric solution.Through use Taguchi found that the accuracy of the measured and prediction values that have been is 93% and 99% for each of the MRR and surface roughness respectively. The effect of different Electrical discharge machining factors are (Gap, pulse off time and pulse on time) to predict the (material removal rate) and (roughness). Note that connected pole that was used is copper. From (ANOVA) found that the large parameter effect on MRR is pulse-on 65% and pulse-off 25% while large parameter effect for surface roughness is pulse-on 96% . The least influential parameter for metal removal rate is the gap and the least influential parameter for surface roughness is pulse-off and Gap.

Study the Effect of Coupling Agents (Polyvinyl alcohol) and (Lignin) on Mechanical Properties for Polymer Composite Materials

Balkees Mohammed Diaa

Engineering and Technology Journal, 2016, Volume 34, Issue 2, Pages 26-34

In this research study the mechanical properties of (Impact, Hardness and Surface roughness) for PMCs materials that used for (Load-bearing structure, Sandwich panels , radio controlled vehicles, sporting goods …etc.), the PMCs materials made from epoxy resin (Polyp rime-EP) type as matrix and a random glass fiber (E-type) as a reinforcementwith volume fraction (20%) by Hand-Lay up process after addition of coupling agent (Polyvinylalcohol (PVA)) with percent of (0.5%) for first sample and addition of coupling agent (Lignin (Lg)) with percent of (0.5%)for second sample but third sample was polymer composite material without addition of coupling agent for comparing with others, and we noticed an enhancement in mechanical properties for polymer composite material after addition of coupling agent. Either when immersion the three samples in solutions, first solution was water (H2O) and the second solution nitric acid (HNO3) diluted with concentration (0.1N), for seven weeks to each solution, mechanical properties were tested for samples every week, showed decreasing in values of mechanical properties, the polymer composite materials that contains coupling agents expressed more resistance than polymer composite material untreated with coupling agent. And the material that contains coupling agent after immersion in water showed much higher resistance to mechanical properties than immersion in diluted nitric acid.

Determining the Effect of Process Parameters on Surface Roughness in two Point Incremental Sheet Metal Forming Process using the Taguchi Method

Harith Yarub Maan

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 1569-1582

The main aim of this study is determining the effect of process parameters on surface roughness in two-point incremental sheet metal forming process using the Taguchi method. The experimental plan and analysis were basedon the mixed L18 Taguchi orthogonal array withfour forming parameters, tool radius (r), feed rate (f), stepover (Δz) and type of support (full and partial support) were analyzed andpyramid shape was used (57°) wall angle. The influence of the process parameters has been investigated and optimum forming condition for minimizing the surface roughness is evaluated. The analysis results show that the stepover has the highest effect on the surface roughness and followed by tool radius, feed rate and die.The result shows that the errorof predicted accuracy for the surface roughness is (1.2%).

Experimental Investigation to Improve Metal Removal Rate (MRR) and Surface Roughness in Electrochemical Machining

Saad Kariem Shather; Baqer Ayad Ahmed

Engineering and Technology Journal, 2012, Volume 30, Issue 11, Pages 1948-1959

Electrochemical machining (ECM) is a non-traditional machining process
which is the controlled removal of metal by anodic dissolution in an electrolytic
cell in which the workpiece is the anode and the tool is cathode. In ECM, metal
removal rate (MRR) takes place due to atomic dissolution of work material.
Electrochemical dissolution is governed by Faraday’s laws.I n this study the ECM
is used to remove metal from the internal hole of the workpiece from aluminum
alloy using NaCl solution. The rates of improvement in MRR are (6.48, 1.81, 3.74,
13.24, 3.11) % for current densities of (2.82, 4.24, 5.65, 7.07, 8.48) A/cm2
respectively, when compared with the stationary tool, and the rotating electrode
gives better surface finish than the stationary electrode, were the enhancement rates
in roughness are (7, 31.72, 7.91, 15.49, 1.34)% for current density values of (2.82,
4.24, 5.65, 7.07, 8.48) A/cm2 respectively.

Study the Effect of Electrical Current on Average Surface Roughness of Borosilicate Glass at EDM Machining and Comparison Using Matlab Program

Shukry H. Aghdeab; Ahmed A. Abulwahhab

Engineering and Technology Journal, 2011, Volume 29, Issue 6, Pages 1157-1165

Machining of electrically non-conducting materials like glass is still a major
problem. The principle of electric arc was used to generate high electrical
discharge (spark) at high currents to machine non-conducting materials at any
hardness.
EDM system was build for machining of non-conducting cutting materials
such as glass including the use of powder (graphite) mixed for dielectric solution
(tap water) by supplied DC current values (200, 250, 300, 350 and 400A). Voltage
of (70V) was used to cut 3mm thickness of borosilicate glass (BSG) to obtain the
average surface roughness (Ra) of about (0.003-0.012μm).
Matlab program has been used to investigate the process control for EDM that
could the Ra experimental and theoretical with accuracies of 94.236, 94.034,
96.628 and 92.875% respectively.
From the reading of the magnitude of the roughness it was found that differences
between the theoretical and experimental values for 3mm thickness of BSG was
never exceed (8%).

Predictive Modeling of Surface Roughness Of Centered And Un-Centered Workpiece Lengths In Turning Operation

Abdullah H. Singal; Farhad M. Kushnaw; Ali Abbar Khleif

Engineering and Technology Journal, 2010, Volume 28, Issue 1, Pages 65-71

The attempt of the present study has addressed an area that has been relatively
neglected in the past researches. This area focuses on studying and analysis the effect
of different centered and un-centered workpiece lengths, using turning machine
tailstock, on the products surface roughness, and then collecting data to generate an
experimental charts and equations for the prediction modeling of surface roughness
and increasing productivity for many turned products. These charts and equations
could be serving as a quick indication for manufacturers to avoid pre-chatter conditions
and the trial and error methods, and consequently reduce the required experience in
this field. So, the applicable range of workpiece lengths can be safely extended from
10 mm to 60 mm bars with 10 mm in diameter, and from 10 to 75 mm bars with 20
mm in diameter. This range could be increasing as bar diameter increasing and vise
versa.

Effect of Current on Average Surface Roughness of Borosilicate Glass at EDM Machining and Comparison with Numerical Programs

Wathik I. Mahdi; Maan A. Tawfiq; Shukry H. Aghdeab

Engineering and Technology Journal, 2009, Volume 27, Issue 6, Pages 1026-1038

Machining of electrically non-conducting materials like glass is still a major problem. The principle of electric arc was used to generate high electrical discharge (spark) at high currents to machine non-conducting materials at any hardness, which is a new approach.
EDM system was build for machining of non-conducting cutting materials such as glass with new technology including the use of powder (graphite) mixed for dielectric solution (tap water) by supplied AC current values (200, 250, 300, 350 and 400A). Voltage of (70V) was used to cut 3mm thickness of borosilicate glass (BSG) to obtain the average surface roughness (Ra) of about (0.003-0.012μm) but the Ra before the machining was (0.005-0.006μm).
Numerical program called "Simulent" has been used to investigate the process control for EDM by using GN, BPN, PN and VQN that could predict the Ra with accuracies of 94.236, 94.034, 96.628 and 92.875% respectively from training data sets.
The differences on the Ra at different network models for 3mm thickness of BSG never exceed (8%) from testing data sets while the comparison of numerical results with experimental results of Ra among the measured values and prediction various network models, shows a differences between (1-8%).
The best predication accuracy is by the use of PN than other network models.