In spite of all the advantages that WJ technology brings when producing electrodes for MEDM, the main problem is how to control the penetration depth of the WJ into the workpiece material. Tool wear was reduced and surface quality was improved at a cutting speed of 100 m/min. As a result, the workpiece quality is poor and tool wear unacceptably high, even for optimized cutting parameters and suitable cutting tools. The Unconventional machining processes do not employ a conventional or traditional tool for metal removal; instead, they directly utilize some form of energy for metal machining. Further reduction of diameter by micro turning may impart the flaws due to wobbling effect; hence it is difficult to fabricate micro tools below 300 μm diameter by conventional machining processes. Cheng et al. In the Electron Beam Machining process, a high velocity focused beam of electrons are used to remove the metal from the workpiece. The authors conducted quasi-static and split-Hopkinson pressure bar compression tests to evaluate the mechanical properties of the material. In this case a WJ cutting head was used with the orifice diameter of 0.1 mm. ECM is capable of machining metals and alloys irrespective of their strength and hardness 2. Other investigations propose cryogenic cooling as being advantageous in comparison to dry and minimum quantity lubrication conditions regarding tool wear and surface quality (Kaynak, Karaca, Noebe, & Jawahir, 2013; Kaynak, Tobe, Noebe, Karaca, & Jawahir, 2014). To avoid premature failure of the tool, low cutting speeds, proper tool materials, and cutting fluids are required (Ezugwu & Wang, 1997). In which metal removal process, material is removed by particles? Fabrication of microtools for EMM is usually done using WEDG (wire electro-discharge grinding), EDM, chemical etching, or even ECM-based processes (34). a) conventional machining 4.1.15 shows voltage and current waveforms of the five discharge states, e.g., (i) Open circuit, (ii) Normal discharge, (iii) Transient arcing, (iv) Harmful Arcing and (v) Short circuit. In this case, a high cutting speed results in small kerf width and the amount of assisting gas passing through the kerf lessens which, in turn, prevents the suppression of the high-temperature oxidation reaction in the region close to the kerf exit. 7.31. View Answer, 15. However, high power density focusing optics (HPDFO) can be used to focus the laser beam with focal spot size of 38 µm in diameter. Fig. b) abrasive process This technology is mostly used to cut softer materials like wood, plastics, rubber, etc. Machining at a defocused condition may produce significantly improved surface roughness without the need of postannealing. The findings of the experimental study pertinent to laser cutting of Kevlar is given herein. The gap between tool and workpiece is continuously monitored and control with the help of a servo control system. In conventional machining process, the material is removed by the direct contact between tool and workpiece. 22.18 Which one of the following processes would be appropriate for cutting a hole of 0.075 mm (0.003 in) diameter through a plate of aluminum that is 1.6 mm (1/16 in) thick: (a) abrasive jet machining, (b) chemical milling, (c) EDM, (d) laser beam machining, (e) … In general, the depth of penetration depends on several process parameters. Plain milling of mild steel plates produces . Such kind of machining normally requires a lot of thermal treatments and wet etching for practical applications. Tools in EMM are often coated with insulating materials such as SiC and Si3N4 on the side walls to reduce the stray current effect, so as to enhance the accuracy of the process. Investigations in the field of AWJ milling [3,4] show that it is difficult to predict and control the depth of penetration of the AWJ into the workpiece material. Being a transparent material, it does not absorb normal IR radiations. 4.4 presents the 3D models of the set of plates required for the mold core and cavity). Conventional Machining Processes 2. a) true 7.34(b). In this case, at high cutting speeds, a discrepancy between predictions and experimental results is observed. [10] b) Is uncoventional machining process an alternate or complement to conventional machining process?Justify. The normal discharge and harmful arcs which can also be differentiated by observing the ignition delay time. 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