Showing 5 results for Electrochemical Discharge
A.h. Torabi, S. Elhami, M.r. Razfar,
Volume 20, Issue 1 (1-2020)
Abstract
Glass as a non-conductive material has special properties such as transparency, chemical resistance, and hardness. Traditional machining methods have noticeable limitations in their capability for shaping the glass parts. Electrochemical discharge machining (ECDM), as an advanced machining method, gives a chance to implement special processes on the glass. There are many effective parameters in the ECDM process and each of them has its special effect, but the influence of electrolyte type has been rarely evaluated in the literature. In this research, the effects of two types of NaOH and H2SO4 electrolytes on the glass have been studied. Electrolyte temperature, as another effective parameter on the chemical reactions, is also considered in these experiments. Surface quality, machining depth and overcut are considered as the machining outputs. The experimental results obtained in this research indicated that the application of H2SO4 acidic electrolyte after machining in NaOH electrolyte rather than machining solely in NaOH electrolyte has a significant effect on the walls of the holes. It is also observed that with a higher electrolyte temperature, the walls of the holes become smoother. It is also shown that, by applying two steps implementation of drilling and application of acidic electrolyte (NaOH/H2SO4), holes have a lower overcut, and the machining depth is improved up to 20.5% in the hydrodynamic regime.
Arsalan Torabi, Mohammad Reza Razfar,
Volume 20, Issue 11 (11-2020)
Abstract
In recent years, forming a 3D microfluidic channels on the electrical non-conductive material such as Polydimethylsiloxane (PDMS) in the micro-electromechanical system (MEMS) and medical applications is of great interest. Lithography is the most know process to create patterns on the PDMS however there are a few drawbacks to this process such as high operational cost and time, and sidewall angle. In all applications, the quality of the microchannel surface determines the performance of it. In this research as innovatively the electrochemical discharge milling (ECDM) which is known for lower operational cost and proper material removal rate (MRR) (i.e. process time), and is capable of creating patterns on electrical non-conductive material, was used to form a microchannel on the PDMS. To that end, the effect of process parameters such as electrolyte concentration, feed rate and cutting speed and voltage on the surface roughness and surface integrity deeply investigated. It was observed that ECDM is capable of creating patterns on the PDMS with surface integrity which is comparable with the lithography microchannel. It is also observed that decreasing the rotational speed from 10000 to 0 rpm results in increasing the surface roughness 2 to 4 times, this happens due to the increasing the thickness of the gas film around the tool, and subsequently increasing the flying sparks which results in higher surface roughness. Increasing the Voltage from 38 to 42 V results in 38% enhancement of surface roughness. The 25% electrolyte concentration results in lower surface roughness.
Pargol Rezvani, Sadegh Elhami, Mohammad Reza Razfar,
Volume 22, Issue 10 (10-2022)
Abstract
Electrochemical discharge machining (ECDM) is a novel non-conventional micro-machining method that can be applied to machining hard, brittle and non-conductive materials such as glass and ceramic. Due to the hardness and brittleness of mentioned materials, the application of conventional machining is associated with serious technical problems. In this article, the machining process was performed in two steps, and hole depth is considered as the main machining output. The obtained results of the new method are compared to single pass micro-drilling (a common micro-drilling process). The achieved results indicated that depth improvements of 36% and 70% were obtained for voltages of 33 and 38V. Also, by increasing the diameter difference, a deeper hole can be achieved.
Sadegh Elhami , Pargol Rezvani, Mohammad Reza Razfar,
Volume 22, Issue 10 (10-2022)
Abstract
Today, the application of materials such as glass has been widely developed in the manufacture of micronutrients, electronics and medical equipment because of its high hardness, chemical resistance and high abrasion. But due to high hardness and low toughness, mechanical machining cannot be applied. The Electrochemical discharge method is a new machining method that is capable of machining hard and non-conductive electrical materials such as glass. In the process of electrochemical discharge drilling, the dimensional accuracy of the hole and especially its inlet area is important. But almost, the inlet of the hole has a high slope, which leads to excessive hole overcut and tapering of the hole side wall. In this study, to remove the high slope entrance area, a thin intermediate part was used which will be separated from the main workpiece after the drilling process. The results showed that mentioned method reduced the entrance overcut of the hole by 50 to 76% depending on the diameter of the tool. Also, the hardness measuring of points on the hole inlet showed that using the intermediate part led to the smaller heat-affected zone (HAZ) around the hole entrance.
Sadegh Elhami, Pargol Rezvani, Mohammad Reza Razfar,
Volume 23, Issue 4 (3-2023)
Abstract
Today, the application of materials such as glass has been widely developed in the
manufacture of micronutrients, electronics and medical equipment because of its high
hardness, chemical resistance and high abrasion. But due to high hardness and low
toughness, mechanical machining can not be applied. The Electrochemical discharge
method is a new machining method that is capable of machining hard and non-conductive
electrical materials such as glass. In the process of electrochemical discharge drilling, the
dimensional accuracy of the hole and especially its inlet area is important. but almost, the
inlet of the hole has a high slope, which leads to excessive hole overcut and tapering of the
hole side wall. In this study, to remove the high slope entrance area, a thin intermediate part
was used which will be separated from the main workpiece after the drilling process. The
results showed that mentioned method reduced the entrance overcut of the hole by 50 to
76% depending on the diameter of the tool. Also, the hardness measuring of points on the
hole inlet showed that using the intermediate part led to the smaller heat-affected zone
(HAZ) around the hole entrance.
