Multi performance optimization of electrochemical micro-machining process surface related parameters on machining Inconel 718 using Taguchi-grey relational analysis

Due to several merits such as higher machining rate and high machining accuracy, electrochemical micromachining (ECMM) is used to machine high strength materials with complex shapes. In this experimental investigation, Inconel 718 specimens have been machined with brass electrode of 500 pm diameter using ECMM. Since electrochemical micromachining involves many responses, Taguchi method along cannot give to find out unique optimum parameter combination of the ECMM process. Therefore, an attempt has been made in the present study to identify the optimum combination of process parameter using grey relational analysis with Taguchi method. The experimental investigation of the process has been conducted with input process parameters such as applied voltage, electrolyte concentration, micro-tool feed rate and duty ratio on material removal rate (MRR), surface roughness (SR) and overcut (OC) with different process level using two electrolytes such as sodium chloride (NaCI) and sodium nitrate (NaNO3). From the experimental results, it has been found that micro-tool feed rate is most influencing nature parameter for NaCI and applied voltage is most influencing nature parameter for NaNO3 in ECMM process

Influence of coated tool electrode on drilling Inconel alloy 718 in Electrochemical micro machining

Since Inconel-718 alloy is high hardened material, it is very difficult to machine the alloy with complex shape using conventional machining process. In the present study, an endeavor has been made to drill the Inconel alloy 718 in micro level using electro chemical machining processes. It has been attempted to find the influence of coatings over copper tool electrode on performance criteria for enhancing the ECM process. From the experimental results, it has been observed that nickel coated copper electrode has produced 7.2% higher material removal whereas chromium coated electrode has produced 19% lower surface roughness over machined alloy specimens. (c) 2016 The Authors. Published by Elsevier B.V

Performance analysis of process variables on laser beam machining of inconel-718 alloy

Carbon-dioxide laser beam machining (LBM) is used for machining intricate shapes and hard materials which are inconceivable with conventional machining methods. Inconel 718 finds its prime applications in manufacturing high pressure turbine components and structural components of aerospace industry.Inconel 718 alloy exhibits superior physical and mechanical properties at elevated temperature, Strength-to-density ratio and higher corrosion resistance. The objective of the current work is to determine the optimal setting of the process parameters like laser power, cutting speed, gas pressure while machining Inconel-718 material using oxygen gas. The experiment was conducted using Taguchi L-9 orthogonal array. A square washer with four holes of diameter 8 mm and one hole of diameter 64 mm was machined using laser beam machining and the best combination of process parameters to acquire better response parameters is computed. The optimized value of surface roughness was found to be 3.5 mu m and similarly material removal rate to be 45.56 m(3)/min when operated at 2.1m/min cutting speed, cut of type rough, lmm of focal point and 4000bar gas pressure, The effect of input variables on various response parameters namely surface roughness (Ra), Heat affected zone thickness (HAZ), material removal rate (MRR), Taper, Circularity, hardness were studied. Morphology of the machined surface was investigated using SEM analysis

Comparison studies on mechanical and wear behavior of Stir Cast Al-SiC-B4C metal matrix composites

This paper studies the surface tribology and mechanical properties of AA6061 graded aluminum alloy matrix composite, reinforcing Silicon Carbide and Boron Carbide. In this work, the AA6061 graded aluminum alloy is reinforced with 3%, 6%, 9% (By weight) of B4C with constant 5% (By weight) of SiC under stir casting and producing three test samples A, B and, C respectively. The Samples were subjected to wear test, tensile test, impact test, and hardness test calculating wear loss, wear rate, coefficient of friction, ultimate tensile strength, impact strength, and brinell hardness. From analyzing the results from the test conducted, it is inferred that maintaining the optimum B4C composition between 3% and 6% in Al-SiC produces better mechanical properties and wear resistance

The Effects of Heat Treatment on The Microstructure and Mechanical Properties of EN19 Steel Alloy

The EN19 steel alloy finds its application in the automotive industry like manufacturing gears, spindles, and shafts. In this paper, we aim to improve the strength and ductility of the EN19 steel alloy by tempering process. Generally, heat treatment is the method of exposing the specimen to high temperatures and cooling it, to bring a change in its physical and chemical properties. In this experiment, the process of annealing, normalizing and quenching followed by tempering were performed on the steel specimens. On heating the specimens to 9000C, and cooling it from slower to a faster rate, we were able to observe and compare the changes in the microstructure, hardness, tensile strength and impact strength of the specimens before and after the heat treatment. On studying the microstructures and grain analysis of the specimens after each heat treatment process, we were able to observe the difference in the composition of the constituents and understand how this affects the mechanical properties of the material. The quenchants used are oil, water and brine solution for quenching. Since the specimens become brittle on quenching, tempering is performed on the specimens to improve the toughness of the material. It is found that the strength of the specimen is improved by quenching and toughness is improved by tempering it. On comparing the values of toughness of the tempered specimens with that of the quenched specimens, it is found that the oil tempered specimen increases by 25%, water tempered specimen by 80% and brine tempered specimen by 75% from the oil quenched, water quenched and the brine quenched specimens respectively

Influence of heat-treated Cu-Be electrode on machining accuracy in ECMM with Monel 400 alloy

Monel 400 is a nickel-copper alloy utilized in marine and oil refining industries owing to its high corrosion resistance and fire withstanding property. The machining of such higher strength material with complex shapes is possible with electrochemical micromachining (ECMM) process, since it can machine with less wear, better precision, micro-level hole profiles, no heat-affected zone and no thermal stresses. The present study was performed with machining of Monel 400 alloy in ECMM process with copper-beryllium wire electrode under various heat treatments, such as annealing, quenching and normalizing. The lower overcut can be obtained using quenched tool electrode when compared to the other treated tools and untreated tool electrode owing to its fine grain structure which restricts the flow of electrons to side of the tool. The conicity with normalized tool electrode is lower, since it exhibits high electrical conductivity by decreasing the distraction of electrons. Circularity with quenched tool electrode is lower due to its fine grain structure and higher electrical conductivity, since its localization effect increases causing uniform stray current

Experimental investigation of abrasive waterjet machining of Nickel based superalloys (Inconel 625)

This work explores abrasive waterjet machining (AWJM) process to improve the machining capabilities of conventional water jet machine by adding abrasive particles to the water jet. The addition of abrasive particles can turn the water jet into a modern machining tool for all materials. The experimental data of cutting parameters for hard-to-machine metal Inconel 625 is obtained. Inconel 625 is machined using an abrasive water jet and the effect of water pressure, abrasive flow rate, stand-off distance, surface quality has been studied and the response parameters are investigated. Experiments were conducted, based on Taguchi's L18 orthogonal array and the process parameters were optimized using Grey relational analysis. Further, the morphological study is made using scanning electron microscope (SEM) on the samples that were machined at optimized parameters. It is observed from the experiment that Stand-off distance is the most influencing parameter among the input parameters

Process parameter optimization of abrasive water jet machining on monel k400 alloy

Nowadays it's difficult to use a metal with high corrosion resistant properties in required applications. Monel 400 is one nickel based alloy having required property to be applicable in such scenarios. It is used in highly corrosive environments such as marine, chemical and aerospace industries as it has the property of maintaining its toughness over a range of temperature, however machining of this Monel alloy is relatively tough due to its characteristic work hardening properties. To tackle the mentioned issues, Abrasive water jet machining is used which is a widely known nontraditional machining technique. The process parameters and the response variables were chosen depending on the machine specifications, and parameter combinations were made using Minitab statistical software. The parameters and their interactions like the cut quality on the alloy, nozzle diameters effects, and water pressure were also studied. Response surface model and various statistical algorithms such as S-N ratio, ANOVA and regression equations were utilized for formation of the design of experiment, optimization of process parameters for the machining process were done using Grey relations. Reduction of surface roughness, maximization of Material removal rate while simultaneously reducing the cycle time for the operation was the primary objective. The results thus obtained indicates that the quality of cut was the most influential factor in the machining process followed by water-jet pressure value

Performance Characteristics of Electrochemical Micromachining on Pure Titanium using coated tool electrode

Owing to its hardenable nature and corrosive resistant, Titanium is mainly utilized in fabricating turbine blade applications. Since it is very tough to creating the complex shape on this material by using traditional machining process. Generally micro holes are produced over the turbine blades to reduce the heat using EDM and LBM process. These processes can produce a heat affected zone over the machining surface and higher operating cost. The target of this present study was to make a micro hole on titanium by using electro chemical micro machining process and also attempt to identify the performance of nickel coated copper electrode for embellishing the ECM process. Since the process involves with no tool wear and less heat affect zone, it is possible to improve the machinability of the material. Titanium specimens have been machined using ECM process with uncoated copper electrode and nickel coated electrode under different process parameters combinations. From the experimental results, the better MRR and surface finish were observed from the nickel coated copper electrode