EDM is a process for removing mater

EDM is a process for removing material, no matter its hardness, by means of the action of series of discharges on electrically conductive materials. Since no mechanical contact occurs during material removal, the EDM process is specially suited for micromachining applications, with a very important focus on complex geometrical features in difficult-to-machine materials such as tungsten carbide, tool steels and aerospace superalloys, amongst others [1] and [2].
Machining forces in EDM are much lower than those exerted between tool and workpiece in mechanical processes such as drilling or grinding. The extreme accuracy resulting from this fact is one of the main reasons that explain the growing impact of EDM for micro-machining applications. On the other hand, the electrodes are simple and they can be easily manufactured in electrode materials such as Copper–Tungsten and graphite using different techniques. All these reasons have contributed to the exponential growth of applications in the field of EDM-drilling of micro-holes. Examples include wire drawing dies, injection nozzles and spinneret holes for synthetic fibers.
In this context, interesting research works can be found in scientific literature dealing with the EDM-drilling of micro-diameter holes in different part materials and with high aspect ratio. In the smallest range ever produced, Egashira et al. [3] reported the production of 0.5 μm diameter micro-holes using silicon electrodes on a machine originally designed for micro-ultrasonic machining. This is the smallest diameter achieved using EDM, which opens the field to submicron and nanoscale machining.
The literature review shows very recent references dealing with aspects such as the geometrical characteristics and the quality of the micro-holes produced by EDM-drilling. Features such as the tapering and the aspect ratio have been deeply analyzed. Again, special mention must be done to the fundamental and applied work carried out by Masuzawa [4] during the last 20 years. Since then, significant advances have been presented to the scientific community and to industry. An interesting contribution to the comparison between the performances of different electrode materials when micro EDM-drilling copper was presented in [5], in which the effect of using positive polarity was first recognized. The commonly accepted limit for the aspect ratio using this process ranges from 15 to 20, the upper limit having been reported in [6]. In this case, the highest aspect ratio is related to the use of a machine fitted with special drives. The use of planetary movement, which is a typical feature in conventional EDM, has been proposed in [7] for producing blind micro-holes of different geometries (not only cylindrical) with aspect ratio about 18:1, which is very close to the upper limit. In a very recent research work Ekmekci and Sayar [8] studied the origin of concavity at the end tip of blind micro-holes produced in a four-axis micro-EDM machine. It is shown that wear at the tip of the electrode can be attributed to accumulation of debris during the discharge process.
Not only the quality of the EDM’ed micro-hole, but also part material is a topic of research interest. In [9], the EDM of micro-holes of different shapes on difficult-to-machine high nickel alloy (trade mark Hymu80) is described. In this work a very interesting proposal that combines micro-EDM with in situ grinding of the previously EDM’ed hole is proposed in order to improve surface finish and contour precision. This second stage is accomplished using a tool with helical groove and SiC particles. Important improvements of surface finish in the nickel alloy (down to Rmax 0.85 μm) have been obtained using this combined strategy. Gray relational analysis method has been used for optimization of micro EDM-drilling of 500 μm diameter holes in the nickel-based alloy Inconel718 [10]. Other very recent references reveal the high scientific and industrial interest of micro-hole EDM drilling of difficult-to-machine materials. For instance, in a recent work [11], micro EDM’drilling of titanium alloy is carried out in a micro-EDM machine. In this case, simultaneous optimization of multiple quality characteristics for this operation using a variation of Taguchi method. In a different line of research, the use of conventional SEDM machinery for micro EDM-drilling had already being pointed out in [12]. As it will be shown later on, holes down to a certain diameter can be effectively machined using conventional equipment, and this is a common problem in industry.
As explained above, in [13], the helical tool geometry previously presented in [9] is applied in combination with ultrasonic machining for micro-hole machining in the same high nickel alloy. In this case, the proposal is based on the fact that the helical geometry can provide gap enough as to improve cleaning conditions, and therefore, remove debris more effectively, when combined with ultrasonic vibration. Very good results are obtained specially in the machining of deep micro-holes, although it is recognized that optimum EDM settings must be derived for the new configuration.
So far research dealing with the micro EDM-drilling process itself has been presented. However, special attention must be paid at the techniques for the manufacturing and set-up of the micro-electrodes. Amongst the techniques for microelectrode manufacturing, mention must be done to the WEDG process [14]. The WEDG process has been used a base technology for the development of complex alternatives such as that described in [3], which allows manufacturing submicron-electrodes of diameter down to 0.15 μm. Very recently [15] the ISEDM process has been introduced as an economical and technically feasible alternative for the manufacturing of cylindrical electrodes of diameter down to 60 μm in conventional EDM machines. This is a distinct feature, since low-cost and popular equipment can be used for the set-up of the electrodes on the same tool-holder where EDM-drilling will take place, avoiding thus the use of additional equipment and the errors introduced by the radial run-out.
In this work a new proposal for the manufacturing of micro-holes by EDM-drilling in difficult-to-machine materials is presented. Set-up of extremely high aspect-ratio electrodes is carried out by using the technology presented in [15]. The performance of the so-prepared cylindrical graphite and CuW electrodes, and the influence of EDM parameters on material removal rate, electrode wear and hole quality when machining Ti6Al4V is studied through experimental tests. Optimization of EDM conditions allows reaching the limits of cylindrical-geometry electrodes for EDM-drilling of high aspect-ratio micro-holes. Useful EDM parameters both for industry and for academia are collected at this point. Then, a new contribution to push forward those limits is introduced. From the ideas pointed out in [9], a new helical-grooved high aspect-ratio electrode has been manufactured using the ISEDM process. The hypothesis is that the increase of volume gained thanks to the flutes of the helix can be used to accommodate the resulting debris and thus, increase process performance. Experimental tests show the influence of helix angle and groove depth on material removal rate. Thanks to the high length of the electrode, holes of 661 μm diameter and as much as 6.81 mm depth (i.e., aspect ratio 10.3:1 can be machined in Ti6Al4V).

ผลลัพธ์ (อังกฤษ) 2:

EDM is a process for removing material, no matter its hardness, by means of the action of series of discharges on electrically conductive materials. Since no mechanical contact occurs during material removal, the EDM process is specially suited for micromachining applications, with a very important focus on complex geometrical features in difficult-to-machine materials such as tungsten carbide, tool steels and aerospace superalloys, amongst others [1. ] and [2].
Machining Forces in EDM are much Lower than those exerted between Tool and workpiece in Mechanical or Grinding Drilling As such processes. The Extreme accuracy resulting from this is one of the main Fact that Explain Reasons for the Growing Impact of EDM Micro - machining Applications. On the Other Hand, the electrodes are Simple and they easily Can be Manufactured in electrode As such Materials Copper - Graphite Tungsten and using different techniques. All these have contributed to the exponential growth of Reasons Applications in the field of EDM - Drilling of Micro - Holes. Examples include Wire Drawing Dies, Injection Nozzles for synthetic fibers and spinneret Holes.
In this context, Interesting Research Scientific literature works Can be Found in Dealing with the EDM - Drilling of Micro - Holes in different Diameter Part Materials and High Aspect ratio with. In the smallest range ever produced, Egashira et al. [3] reported the Production of 0.5 Connect M Diameter Micro - Holes using electrodes on a Silicon Originally designed for Micro Machine - ULTRASONIC machining. This is achieved using the Smallest Diameter EDM, which opens the field to submicron and nanoscale machining.
The literature review shows very recent references Dealing with such aspects As the geometrical characteristics and the quality of the Micro-Holes-produced by EDM Drilling. Features such as the tapering and the aspect ratio have been deeply analyzed. Again, special mention must be done to the fundamental and applied work carried out by Masuzawa [4] during the last 20 years. Since then, significant advances have been presented to the scientific community and to industry. An interesting contribution to the comparison between the performances of different electrode materials when micro EDM-drilling copper was presented in [5], in which the effect of using positive polarity was first recognized. The commonly accepted limit for the aspect ratio using this process ranges from 15 to 20, the upper limit having been reported in [6]. In this case, the highest aspect ratio is related to the use of a machine fitted with special drives. The use of planetary movement, which is a typical feature in conventional EDM, has been proposed in [7] for producing blind micro-holes of different geometries (not only cylindrical) with aspect ratio about 18: 1, which is very close to the. upper limit. In a very recent research work Ekmekci and Sayar [8] studied the origin of concavity at the end tip of blind micro-holes produced in a four-axis micro-EDM machine. It is shown that at the Tip of the electrode Wear Can be attributed to the accumulation of debris during discharge Process.
Not only the quality of the EDM ' ED Micro - Hole, but also Part Material is a Research Topic of interest. In [9], the EDM of Micro - Holes of different Shapes on difficult - to - Machine High Nickel Alloy (Trade Mark Hymu80) is described. Work in this proposal that combines a very Interesting Micro - EDM with in situ Grinding of the previously EDM ' ED Hole in Proposed Order is to improve surface and Contour Precision Finish. This second stage is accomplished using a tool with helical groove and SiC particles. Improvements of important surface Finish in the Nickel Alloy (down to 0.85 Rmax Connect M) have been obtained using this combined Strategy. Gray relational Analysis method has been used for Optimization of Micro EDM - Drilling of 500 Connect M Diameter Holes in the Nickel - based Alloy Inconel718 [10]. Other very recent references Reveal the High Scientific and industrial interest of Micro - EDM Hole Drilling of difficult - to - Machine Materials. For instance, in a recent Work [11], Micro EDM ' Drilling of Titanium Alloy is carried out in a Micro - EDM Machine. In this case, simultaneous optimization of multiple quality characteristics for this operation using a variation of Taguchi method. In a different line of Research, the use of conventional SEDM Machinery for Micro EDM - Drilling had already being Pointed out in [12]. As it Will be shown later on, Holes down to a certain Diameter Can be effectively machined using conventional Equipment, and this is a common Problem in Industry.
As explained above, in [13], the helical Tool Geometry previously Presented in [9]. is applied in combination with ultrasonic machining for micro-hole machining in the same high nickel alloy. In this case, the proposal is based on the fact that the helical geometry can provide gap enough as to improve cleaning conditions, and therefore, remove debris more effectively, when combined with ultrasonic vibration. Very good results are obtained specially in the machining of Micro Deep-Holes, Although it is recognized that Optimum EDM settings must be derived for the New Configuration.
So Far Research Dealing with the Micro EDM - Drilling Process has been Presented Itself. However, Special Attention must be paid at the techniques for the Manufacturing and SET - up of the Micro - electrodes. Amongst the techniques for microelectrode manufacturing, mention must be done to the WEDG process [14]. The WEDG has been used a Base Technology Process for the Development of Complex Alternatives such that As described in [3], which submicron Allows Manufacturing - Diameter of electrodes down to 0.15 Connect M. Very recently [15] As the ISEDM Process has been introduced and technically feasible an Economical Alternative for the Manufacturing of cylindrical electrodes of Diameter down to 60 Connect M in conventional EDM Machines. This is a Distinct Feature, since low - cost and popular Equipment Can be used for the SET - up of the electrodes on the Same Tool - Holder where EDM - Drilling Will take Place, avoiding thus the use of Additional Equipment and the Errors introduced by. the Radial Run-out.
In this New Work a proposal for the Manufacturing of Micro - Holes by EDM - Drilling in difficult - to - Machine Materials Presented is. Set - up of extremely High Aspect - ratio is carried out by using the electrodes Technology Presented in [15]. The Performance of the so - Graphite and CuW prepared cylindrical electrodes, and the influence of EDM Parameters on Material Removal rate, electrode Wear and quality when machining Ti6Al4V is studied Through Hole Experimental tests. Optimization of EDM conditions Allows reaching the Limits of cylindrical - Geometry electrodes for EDM - Drilling of High Aspect - ratio Micro - Holes. Useful EDM parameters both for industry and for academia are collected at this point. Then, a new contribution to push forward those limits is introduced. Ideas from the Pointed out in [9], a New helical - grooved High Aspect - ratio has been electrode Manufactured using the ISEDM Process. The hypothesis is that the increase of volume gained thanks to the flutes of the helix can be used to accommodate the resulting debris and thus, increase process performance. Experimental tests show the influence of helix angle and groove depth on material removal rate. Thanks to the High Length of the electrode, Holes of 661 Connect and M Diameter 6.81 mm As As much depth (IE, Aspect ratio 10.3: 1 Can be machined in Ti6Al4V).

ผลลัพธ์ (อังกฤษ) 3:

EDM is a process for removing material no matter, its hardness by means, of the action of series of discharges on electrically. Conductive materials. Since no mechanical contact occurs during, material removal the EDM process is specially suited for. Micromachining applications with a, very important focus on complex geometrical features in difficult-to-machine materials. Such as, tungsten carbideTool steels and, aerospace superalloys amongst others [1] and [2].
Machining forces in EDM are much lower than those exerted. Between tool and workpiece in mechanical processes such as drilling or grinding. The extreme accuracy resulting from this. Fact is one of the main reasons that explain the growing impact of EDM for micro-machining applications. On the, other handThe electrodes are simple and they can be easily manufactured in electrode materials such as Copper - Tungsten and graphite. Using different techniques. All these reasons have contributed to the exponential growth of applications in the field of. EDM-drilling of micro-holes. Examples include wire, drawing dies injection nozzles and spinneret holes for synthetic fibers.
In. This, contextInteresting research works can be found in scientific literature dealing with the EDM-drilling of micro-diameter holes. In different part materials and with high aspect ratio. In the smallest range ever produced Egashira et, al. [], 3 reported The production of 0.5 thermal m diameter micro-holes using silicon electrodes on a machine originally designed for micro-ultrasonic. Machining.This is the smallest diameter achieved, using EDM which opens the field to submicron and nanoscale machining.
The literature. Review shows very recent references dealing with aspects such as the geometrical characteristics and the quality of the. Micro-holes produced by EDM-drilling. Features such as the tapering and the aspect ratio have been deeply, Again analyzed.Special mention must be done to the fundamental and applied work carried out by Masuzawa [] during 4 the last 20, years. Since then significant advances, have been presented to the scientific community and to industry. An interesting contribution. To the comparison between the performances of different electrode materials when micro EDM-drilling copper was presented. 5, in []In which the effect of using positive polarity was first recognized. The commonly accepted limit for the aspect ratio using. This process ranges from 15, to 20 the upper limit having been reported in [6]. In, this case the highest aspect ratio is. Related to the use of a machine fitted with special drives. The use of, planetary movement which is a typical feature in. Conventional, EDMHas been proposed in [] for 7 producing blind micro-holes of different geometries (not only cylindrical) with aspect ratio. About 18: 1 which is, very close to the upper limit. In a very recent research work Ekmekci and Sayar [] studied 8 the origin. Of concavity at the end tip of blind micro-holes produced in a four-axis micro-EDM machine.It is shown that wear at the tip of the electrode can be attributed to accumulation of debris during the discharge process.
Not. Only the quality of the EDM ', ed micro-hole but also part material is a topic of research interest. In [9], the EDM of micro-holes. Of different shapes on difficult-to-machine high nickel alloy (trade mark Hymu80) is described.In this work a very interesting proposal that combines micro-EDM with in situ grinding of the previously EDM ed hole is. ' Proposed in order to improve surface finish and contour precision. This second stage is accomplished using a tool with helical. Groove and SiC particles. Important improvements of surface finish in the nickel alloy (down to Rmax 0.85 thermal m) have been obtained using this combined strategy. Gray relational analysis method has been used for optimization. Of micro EDM-drilling of 500 thermal m diameter holes in the nickel-based alloy Inconel718 [10]. Other very recent references reveal. The high scientific and industrial interest of micro-hole EDM drilling of difficult-to-machine materials. For, instance. In a recent 11, work []Micro EDM 'drilling of titanium alloy is carried out in a micro-EDM machine. In this case simultaneous optimization, of. Multiple quality characteristics for this operation using a variation of Taguchi method. In a different line, of research. The use of conventional SEDM machinery for micro EDM-drilling had already being pointed out in [12]. As it will be shown. Later, onHoles down to a certain diameter can be effectively machined using conventional equipment and this, is a common problem. In industry.
As, explained above in [13], the helical tool geometry previously presented in [] is 9 applied in combination. With ultrasonic machining for micro-hole machining in the same high nickel alloy In, this case.