EDM Drilling and Shaping of Cooling Holes in Inconel 718 Turbine Blades

Kliuev, Mikhail; Boccadoro, Marco; Pérez, Rebeca; Bó, W. Dal; Stirnimann, Josef; Kuster, Friedrich; Wegener, Konrad

doi:10.1016/j.procir.2016.02.293

Cited by 70 publications

(29 citation statements)

References 12 publications

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“…The input parameters are drilling speed, recast layer thickness, and hole taper. In Inconel 718, drilling and shaping process made into a single progression with identical electrode found that shape accuracy is affected by relative tool wear [10]. MRR, relative tool wear, and surface reliability are the objective parameters.…”

Section: Literature Reviewmentioning

confidence: 99%

Experimental Investigation of Drilling Small Hole on Duplex Stainless Steel (SS 2205) Using EDM

Rajaram¹,

Rajkumar²,

Balasundaram³

et al. 2019

Mechanics and Mechanical Engineering

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This work investigates drilling of small holes of 3 mm in diameter on duplex stainless steel. Its machinability index is very low (0.66) when compared to other steels; hence, electrical discharge machining is used. The input parameters are current, spark gap, and dielectric pressure. Each input parameter is considered for three levels. Therefore, the total number of experiments is 3 × 3 × 3 = 27. To reduce the number of runs, Taguchi L9 orthogonal array is used, which have the advantage of maximum and minimum trial runs in its design. The output response is metal removal rate (MRR). To find the best operating parameter, the regression model generated using ANOVA is given as input for MATLAB genetic algorithm (GA). The experimental results indicated that models are significant. The test result indicated that the contribution of the current on the MRR is 42.42%, dielectric pressure is 35.36%, and spark gap is 1.93%. From GA, it is observed that among these three factors, lower value of current and dielectric pressure produced the maximum MRR. The SS 2205 has wide variety of applications, such as high pressure components and control valves, which have large number of components attached to it. Hence, performing micro holes on such high hardness alloy is useful.

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Section: Literature Reviewmentioning

confidence: 99%

Experimental Investigation of Drilling Small Hole on Duplex Stainless Steel (SS 2205) Using EDM

Rajaram¹,

Rajkumar²,

Balasundaram³

et al. 2019

Mechanics and Mechanical Engineering

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“…The erosion current, I d , is set to 8 A and open voltage, U op , is set to 100 V. As mentioned in [36], the layer thickness per one pass cannot be higher than a half of electrode radius, which is considered in the present work. The diameter of the pyrometer fiber is 0.5 mm.…”

Section: Desigmentioning

confidence: 99%

Temperature and force measurements in single diamond scratch tests

Akbari

Kliuev

Boos

et al. 2018

Int J Adv Manuf Technol

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Analysis of the highest temperature in the machining processes, namely the flash temperature, helps to understand the physics of the process, to improve cutting tool geometry and to achieve high performance machining. In the present work, the interaction between cutting grain and workpiece material in grinding process is analyzed. Single diamonds are considered for machining, which operates in comparison to other measurements in the range of grinding speed. The highest temperature in the grain-material interaction and cutting forces are measured. In order to measure the flash temperature an innovative method to measure and analyze the temperature through the diamond grain in the cutting zone by two-color pyrometer are proposed. Furthermore, cutting forces are measured simultaneously. In order to measure the temperature in the cutting zone, an accurate connection between diamond and pyrometer fiber is required. Thus, the diamond tool holders are manufactured by electrical discharge machining (EDM)-milling in deionized water. A 0.5 mm diameter hole is drilled in each holder, to connect the diamond precisely to the pyrometer fiber. Machining processes are performed with 30 µm depth of cut, cutting length of 20 mm and cutting speed of 65 m/s on Ti6Al4V. The cutting tool is fixed and the shape of the rotating workpiece is optimized. The diamond holder with the specific shape is designed and manufactured. Quasi-static, dynamic, modal and harmonic response analyses are performed in order to reduce vibrations and chattering. The measured flash temperature is 1380 °C and cutting normal, tangential and axial forces are measured.

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“…Due to extremely tough nature (such as lower thermal conductivity, high work hardening, presence of abrasive carbide particles, high hardness, affinity to react with tool material, high toughness) of the Inconel 718 superalloy, the making of high aspect ratio holes in its structure involves significant difficulties in the case of conventional machining [5,6]. In order to overcome the limitations, the aerospace industry currently applies non-conventional methods such as electrochemical machining (ECM), laser beam machining (LBM) and electrical discharge machining (EDM) to produce micro-scale cooling holes in superalloy materials [7].…”

Section: Introductionmentioning

confidence: 99%

“…To enhance the additional resistance of these materials of components into high temperature, a considerable number of holes (20,000-40,000) with a diameter in the range of 0.3-5 mm and an aspect ratio in the range of (40-600):1 (depth-to-diameter ratio) are made in their structure [5,[8][9][10]. The main task of the holes (named "cooling holes") is to reduce the temperature of the component material by flow of the cooling factor (gas or liquid) through the holes [7]. The efficiency of the cooling process depends on the dimensional shape accuracy and the quality of the holes' inner surface.…”

Section: Introductionmentioning

confidence: 99%

Impact of the Deionized Water on Making High Aspect Ratio Holes in the Inconel 718 Alloy with the Use of Electrical Discharge Drilling

et al. 2020

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Nickel-based superalloys are being increasingly applied to manufacture components in the aviation industry. The materials are classified as difficult-to-machine using conventional methods. Nowadays, manufacturing techniques are needed to drill high aspect ratio holes of above 20:1 (depth-to-diameter ratio) in these materials. One of the most effective methods of making high-aspect-ratio holes is electrical discharge drilling (EDD). While drilling high aspect ratio holes, a crucial issue is the flushing of the gap area and the evacuation of the erosion products. The use of deionized water as the dielectric fluid in the EDD offers a considerable potential. This paper includes an analysis of the influence of the machining parameters (pulse time, current amplitude and discharge voltage) on the process performance (drilling speed, linear tool wear, taper angle, hole’s aspect ratio, side gap thickness), during the EDD with the use of deionized water in the Inconel 718 alloy. The obtained through holes were subjected to the extended analysis. The impact of the initial working fluid temperature and pressure on the conditions of the flow through the electrode channel was also subjected to the analysis. The deionized water properties were changed by applying an initial temperature. Based on the results of an analysis of the previous research, the EDD of the through holes was performed for a pre-set initial temperature (~313.15 °K) and initial pressure of the working fluid (8 MPa) and selected process parameters. An analysis of the results indicates increasing of hole’s aspect ratio by about 15% (above 30), decreasing the side gap thickness by about 40% and enhanced surface integrity.

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EDM Drilling and Shaping of Cooling Holes in Inconel 718 Turbine Blades

Cited by 70 publications

References 12 publications

Experimental Investigation of Drilling Small Hole on Duplex Stainless Steel (SS 2205) Using EDM

Experimental Investigation of Drilling Small Hole on Duplex Stainless Steel (SS 2205) Using EDM

Temperature and force measurements in single diamond scratch tests

Impact of the Deionized Water on Making High Aspect Ratio Holes in the Inconel 718 Alloy with the Use of Electrical Discharge Drilling

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