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Calculation the cutting force in machining processes is of great importance. In this paper, undeformed chip thickness in one-dimensional ultrasonic vibration assisted milling is calculated and then, a model for determining the cutting force in this process is presented. Analytical relations show that in ultrasonic assisted milling (UAM), the maximum cutting force is greater than in conventional milling (CM), but the average cutting force is decreased. To verify the proposed relations, with the aid of a particular experimental setup, one-dimensional vibration in feed direction is applied to workpiece and cutting force in CM and UAM is measured experimentally. Greater maximum cutting force in UAM and decrease of average cutting force in UAM compared to CM is observed experimentally as well. Comparison of average values of cutting force shows that the analytical relations for predicting the cutting force have 16% average error in CM and 40% average error in UAM. Given that the analytical calculation of undeformed chip thickness and cutting force in UAM and also comparison of experimental forces with the modeled ones has been done in this paper for the first time, the accuracy of proposed relations are acceptable.

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Plasma assisted machining (PAM) is a method to improve machinability of hard turning. The process of plasma assisted machining for turning applications utilizes a high-temperature plasma arc to provide a controlled source of localized heat, which softens only that small portion of the work material removed by the cutting tool. The goal of this study is to present a methodology for determination cutting force during plasma enhanced turning of hardened steel AISI 4140. In this regard, a finite differential model was made to estimate the uncut chip temperature under different plasma currents, cutting speeds and feeds during PAM. A mechanistic model developed to estimate cutting force under different PAM conditions by considering shear stresses in the primary, secondary shear zones and force on the tool edge. The proposed model was calibrated with experimental hard turning data, and further validated over practical PAM conditions. Mean errors of predicted values and experimental data is lower than 10 percent. It is shown that PAM can decrease main cutting force in comparison to convectional to 40 percent in turning of hardened steel at high levels of uncut chip temperature due to softening the material.

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Reduction of cutting force in a machining process offers several advantages including increase in tool life, and improvement in the quality of the machined surface. One the new techniques for reducing cutting force relates to ultrasonic vibration assisted machining. In the present paper, one-dimensional ultrasonic vibration-assisted side milling process of Al7022 aluminum alloy has been studied. In order to investigate the effect of cutting speed, feed rate, radial depth of cut, and vibration amplitude on three cutting force components and their resultant, a special experimental setup has been designed and established which applies one dimensional ultrasonic vibration to work piece. Applying the ultrasonic vibrations on milling process, affects mostly on feed component of cutting force which is unidirectional with the work piece vibration, and decreases it by 33.5% in average. Decrease in cutting speed and increase in vibration amplitude, results to increase the separation of tool and work piece from each other in a portion of each vibration cycle, and larger decrease of the feed force. The average decrease of the resultant cutting force in ultrasonic-assisted milling process is 10.8%.

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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.

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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.

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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. 

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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.