scholarly journals An experimental study of surface roughness in electrical discharge machining of AISI 304 stainless steel

2018 ◽  
Vol 38 (2) ◽  
pp. 90-96 ◽  
Author(s):  
IGNACIO HERNÁNDEZ CASTILLO ◽  
ORQUÍDEA SÁNCHEZ LÓPEZ ◽  
GUILLERMO ARTURO LANCHO ROMERO ◽  
CUAUHTÉMOC HÉCTOR CASTAÑEDA ROLDÁN

The effect of the pulse current, pulse on time and pulse off time on the surface roughness of AISI 304 stainless steel workpieces produced by electric discharge machining (EDM) using grade GSP-70 graphite electrodes was studied. A factorial design was performed, considering two levels for each of the three established parameters. From the statistical analysis, it was obtained that the pulse current and pulse on time are the most significant machining parameters on the obtained surface roughness values of the stainless steel AISI 304 workpieces machined by EDM. On the other hand, the regression analysis of a second order model was done to estimate the average roughness (Ra) in terms of the pulse current, pulse on time and pulse off time. Finally, the mean absolute percentage error (MAPE) of the roughness values estimated by the second order regression model and the roughness obtained experimentally is also presented.

Author(s):  
Gregory Bicknell ◽  
Guha Manogharan

Wire electric discharge machining (EDM) is a non-traditional machining method that has the ability to machine hard, conductive materials, with no force and high precision. This technology is used in industries, like the aerospace industry, to create precision parts used in high stress applications. Wire EDM is also commonly used in additive manufacturing (AM) applications to remove printed parts from the base-plates onto which they are printed. Numerous studies show the effects of EDM parameters, like pulse-on time, pulse-off time, and cutting voltage, on the processing of traditionally fabricated metal parts. However, very few studies identify how the parameters of wire EDM affect the processing of AM parts. This paper studies the effect of wire EDM pulse-on time, pulse-off time, and cutting voltage on the machining time, surface roughness, and hardness of additively manufactured 316L stainless steel cylinders. The effects of these wire EDM parameters are then tested on the machining time, surface roughness, and hardness of wrought 316L stainless steel cylinders. It was found that machining time of AM samples was statistically significantly lower than wrought samples and also had better surface finish and lower surface hardness.


2020 ◽  
Vol 62 (9) ◽  
pp. 957-961
Author(s):  
Nursel Altan Özbek ◽  
Metin İbrahim Karadag ◽  
Onur Özbek

Abstract This paper presents the effect of cutting tool, cutting speed and feed rate on the flank wear and surface roughness of austenitic stainless steel (AISI 304) during wet turning. Turning tests were designed based on the Taguchi method (L18). An orthogonal array, the signal-to-noise ratio (S/N) and the ANOVA were used to investigate the machinability of AISI 304 stainless steel with PVD and CVD coated tungsten carbide inserts. As a result of ANOVA, it was found that the feed rate was the most effective parameter on both flank wear and surface roughness.


Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1408
Author(s):  
Yu-Hsuan Chung ◽  
Tai-Cheng Chen ◽  
Hung-Bin Lee ◽  
Leu-Wen Tsay

The effects of micro-shot peening on the rotating bending fatigue resistance of AISI 304 stainless steel (SS) were investigated in this study. The strain-hardening, surface roughness and induced residual stress were inspected and correlated with fatigue strength. Micro-shot peening caused intense strain-hardening, phase transformation and residual stress but was also accompanied by a minor increase in surface roughness. A nanograined structure, which was advantageous to fatigue resistance, was observed in the severe shot-peened layer. The absence of microcracks, minor increase in surface roughness, nanograined structure and induced high compressive residual stress in the shot-peened layer were responsible for the improved fatigue strength of AISI 304 SS.


Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 36 ◽  
Author(s):  
Thi-Hong Tran ◽  
Manh-Cuong Nguyen ◽  
Anh-Tung Luu ◽  
The-Vinh Do ◽  
Thu-Quy Le ◽  
...  

As a successful solution applied to electrical discharge machining (EDM), powder-mixed electrical discharge machining (PMEDM) has been proposed as an upgrade of the EDM process. The optimization of the process parameters of PMEDM is essential and pressing. In this study, Taguchi methods and analysis of variance (ANOVA) were used to find the main parameters affecting surface roughness in the EDM process with SiC powder-mixed-dielectric of hardened 90CrSi steel. The PMEDM parameters selected were the powder concentration, the pulse-on-time, the pulse-off-time, the pulse current, and the server voltage. It was found that SiC powder exhibits positive effects on reducing surface roughness. The roughness obtained with the optimum powder concentration of 4 g/L was reduced by 30.02% compared to that when processed by conventional EDM. Furthermore, the pulse-off-time was found to be the most influential factor that gave an important effect on surface roughness followed by the powder concentration. The EDM condition including a powder concentration of 4 g/L, a pulse-on-time of 6 µs, a pulse-off-time of 21 µs, a pulse current of 8 A, and a server voltage of 4 V resulted in the best surface roughness.


2006 ◽  
Vol 200 (20-21) ◽  
pp. 5807-5811 ◽  
Author(s):  
Gajendra Prasad Singh ◽  
J. Alphonsa ◽  
P.K. Barhai ◽  
P.A. Rayjada ◽  
P.M. Raole ◽  
...  

2021 ◽  
Vol 118 (6) ◽  
pp. 615
Author(s):  
Narayanasamy Ananthi ◽  
Uthirapathi Elaiyarasan ◽  
Vinaitheerthan Satheeshkumar ◽  
Chinnamuthu Senthilkumar ◽  
Subbarayan Sathiyamurthy ◽  
...  

Magnesium and its alloys play a vital role in various applications such as automobile, aircraft, biomedical and military etc. Mg alloys have superior characteristics such as light weight, high strength, good damping capacity and easily castability etc. Eventhough it has attractive range of properties, the machining of magnesium alloys using conventional machining methods is difficult. To overcome that issue, non traditional machining is considered as a potential process. EDM is an electro thermal process extensively used for machining hard materials. In this investigation, the ZE41A magnesium alloy is machined using EDM with copper electrode. In order to improve surface characteristics such as material removal rate (MRR) and surface roughness (SR), various parameters namely current, pulse on time and pulse off time were selected. The regression values of MRR and SR are 97.20% and 99.62% respectively indicating an empirical relationship between the parameters and responses. Pulse off time was found as a significant parameter on the response followed by pulse on time and current. MRR and SR increased with increasing current, pulse on time and pulse off time. At a current of 5A, the produced spark density is high so that the removed quantity of material from the workpiece is high. At a pulse on time of 95 μs, the spark intensity is high affecting the local temperature in the machined zone, and hence MRR increases. SR drastically increases at increasing current. At higher current, large size crater are observed on the machined surface that made the surface rough, and hence SR increases.


Author(s):  
J. A. Korbonski ◽  
L. E. Murr

Comparison of recovery rates in materials deformed by a unidimensional and two dimensional strains at strain rates in excess of 104 sec.−1 was performed on AISI 304 Stainless Steel. A number of unidirectionally strained foil samples were deformed by shock waves at graduated pressure levels as described by Murr and Grace. The two dimensionally strained foil samples were obtained from radially expanded cylinders by a constant shock pressure pulse and graduated strain as described by Foitz, et al.


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