scholarly journals Machinability Analysis and Optimization in Wire EDM of Medical Grade NiTiNOL Memory Alloy

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2184 ◽  
Author(s):  
Vinayak N. Kulkarni ◽  
V. N. Gaitonde ◽  
S. R. Karnik ◽  
M. Manjaiah ◽  
J. Paulo Davim
Keyword(s):  
Differential Evolution ◽  
Shape Memory ◽  
Removal Rate ◽  
Optimization Technique ◽  
Experimental Studies ◽  
Wire Electric Discharge Machining ◽  
Nitinol Alloy ◽  
Machinability Analysis ◽  
Wire Feed ◽  
Medical Grade

NiTiNOL (Nickel–Titanium) shape memory alloys (SMAs) are ideal replacements for titanium alloys used in bio-medical applications because of their superior properties like shape memory and super elasticity. The machining of NiTiNOL alloy is challenging, as it is a difficult to cut material. Hence, in the current research the experimental studies on machinability aspects of medical grade NiTiNOL SMA during wire electric discharge machining (WEDM) using zinc coated brass wire as electrode material have been carried out. Pulse time (Ton), pause time (Toff), wire feed (WF), and servo voltage (SV) are chosen as varying input process variables and the effects of their combinational values on output responses such as surface roughness (SR), material removal rate (MRR), and tool wear rate (TWR) are studied through response surface methodology (RSM) based developed models. Modified differential evolution (MDE) optimization technique has been developed and the convergence curve of the same has been compared with the results of differential evolution (DE) technique. Scanning electron microscopy (SEM) and energy dispersive X-ray spectrography (EDS) analysis are carried out to study the surface morphology of the machined alloy. SV is found to be more influential process parameter for achieving better MRR with minimal SR and TWR, followed by Ton, Toff, and WF. The WF has good impact on reduced SR and TWR responses and found to be least significant in maximizing MRR.

Multi-Response Optimization of Micro-WEDM Process Parameters of Ti49.4-Ni50.6 Shape Memory Alloy for Orthopedic Implant Application

2018 ◽  
Vol 1150 ◽  
pp. 1-21
Author(s):  
Adik M. Takale ◽  
Nagesh K. Chougule ◽  
Preetam H. Selmokar ◽  
M.G. Gawari
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Process Parameters ◽  
Removal Rate ◽  
Orthopedic Implant ◽  
Wire Tension ◽  
Response Optimization ◽  
Micro Wedm ◽  
Wedm Process ◽  
Wire Feed

The present work deals with the optimization of micro-WEDM process parameters for machining Ti49.4-Ni50.6 shape memory alloy (SMA) for orthopedic implant application. Effect of micro-WEDM parameters viz. Gap voltage, capacitance, wire feed and wire tension on the response variables such as material removal rate, surface roughness, kerf width and dimensional deviation is determined. As Ti-Ni SMA has fascinating properties and bio-compatibility, have been considered for present work. Nine experiments have been performed on micro-WEDM based on an orthogonal array of Taguchi method. Subsequently, the grey relational analysis (GRA) method is applied to determine an optimal set of process parameters. It is observed that optimized set of parameters A3B3C3D1 viz. 140 V gap voltage, 0.4 µF capacitance, wire feed 30 µm/sec and 30% of wire tension determined by using GRA offers maximum MRR and minimum SR, KW and DD. From the Analysis of Variance, it is seen that the process parameter capacitance is the most significant parameter for multi-response optimization with a percentage contribution of 77.91%. Young’s modulus also checked for biocompatibility. Also, SEM images are taken to confirm the results offering better surface quality. Heat treatment process like annealing is found to be the most suitable to recover shape memory effect of WEDMed samples.

scholarly journals A Detailed Machinability Assessment of DC53 Steel for Die and Mold Industry through Wire Electric Discharge Machining

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 816
Author(s):  
Sarmad Ali Khan ◽  
Mudassar Rehman ◽  
Muhammad Umar Farooq ◽  
Muhammad Asad Ali ◽  
Rakhshanda Naveed ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Physical Science ◽  
Material Removal ◽  
Removal Rate ◽  
Recast Layer ◽  
Electric Discharge Machining ◽  
Recast Layer Thickness ◽  
Wire Electric Discharge Machining ◽  
Die And Mold ◽  
Wire Feed

Recently, DC53 die steel was introduced to the die and mold industry because of its excellent characteristics i.e., very good machinability and better engineering properties. DC53 demonstrates a strong capability to retain a near-net shape profile of the die, which is a very challenging process with materials. To produce complex and accurate die features, the use of the wire electric discharge machining (WEDM) process takes the lead in the manufacturing industry. However, the challenge is to understand the physical science of the process to improve surface features and service properties. In this study, a detailed yet systematic evaluation of process parameters investigation is made on the influence of a wire feed, pulse on duration, open voltage, and servo voltage on the productivity (material removal rate) and material quality (surface roughness, recast layer thickness, kerf width) against the requirements of mechanical-tooling industry. Based on parametric exploration, wire feed was found the most influential parameter on kerf width: KW (45.64%), pulse on time on surface roughness: SR (84.83%), open voltage on material removal rate: MRR (49.07%) and recast layer thickness: RLT (52.06%). Also, the optimized process parameters resulted in 1.710 µm SR, 10.367 mm3/min MRR, 0.327 mm KW, and 10.443 µm RLT. Moreover, the evolution of surface features and process complexities are thoroughly discussed based on the involved physical science. The recast layer, often considered as a process limitation, was explored with the aim of minimizing the layers’ depth, as well as the recast layer and heat-affected zone. The research provides regression models based on thorough investigation to support machinists for achieving required features.

Experimental Study of Machining of Shape Memory Alloys Using Dry Micro Electrical Discharge Machining Process

2018 ◽  
Author(s):  
Sagil James ◽  
Sharadkumar Kakadiya
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Dielectric Medium ◽  
Machining Process ◽  
Machining Processes ◽  
Micro Electrical Discharge Machining

Shape Memory Alloys are smart materials that tend to remember and return to its original shape when subjected to deformation. These materials find numerous applications in robotics, automotive and biomedical industries. Micromachining of SMAs is often a considerable challenge using conventional machining processes. Micro-Electrical Discharge Machining is a combination of thermal and electrical processes, which can machine any electrically conductive material at micron scale independent of its hardness. It employs dielectric medium such as hydrocarbon oils, deionized water, and kerosene. Using liquid dielectrics has adverse effects on the machined surface causing cracking, white layer deposition, and irregular surface finish. These limitations can be minimized by using a dry dielectric medium such as air or nitrogen gas. This research involves the experimental study of micromachining of Shape Memory Alloys using dry Micro-Electrical Discharge Machining process. The study considers the effect of critical process parameters including discharge voltage and discharge current on the material removal rate and the tool wear rate. A comparison study is performed between the Micro-Electrical Discharge Machining process with using the liquid as well as air as the dielectric medium. In this study, microcavities are successfully machined on shape memory alloys using dry Micro-Electrical Discharge Machining process. The study found that the dry Micro-Electrical Discharge Machining produces a comparatively better surface finish, has lower tool wear and lesser material removal rate compared to the process using the liquid as the dielectric medium. The results of this research could extend the industrial applications of Micro Electrical Discharge Machining processes.

Application of Biofilm Kinetics to Anaerobic Fixed Bed Reactors

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1319-1326 ◽  
Author(s):  
I. E. Gönenç ◽  
D. Orhon ◽  
B. Beler Baykal
Keyword(s):  
Removal Rate ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Pilot Scale ◽  
Cod Removal ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Removal Mechanism ◽  
Term Operation ◽  
Fixed Bed Reactors

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application. In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.

scholarly journals Multi-Objective Optimization of Process Parameters for Powder Mixed Electrical Discharge Machining of Inconel X-750 Alloy Using Taguchi-Topsis Approach

2021 ◽  
Vol 71 (1) ◽  
pp. 1-18
Author(s):  
Basha Shaik Khadar ◽  
Raju M. V. Jagannadha ◽  
Kolli Murahari
Keyword(s):  
Boron Carbide ◽  
Process Parameters ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Optimization Technique ◽  
Dielectric Fluid ◽  
Carbide Powder ◽  
Powder Concentration ◽  
Pulse On Time ◽  
Pulse Off Time

Abstract The paper investigates the influence of boron carbide powder (B4C) mixed in dielectric fluid on EDM of Inconel X-750 alloy. The process parameters selected as discharge current (Ip), pulse on time(Ton), pulse off time(Toff), boron carbide(B4C) powder concentration to examine their performance responses on Material Removal Rate (MRR), Surface Roughness(Ra) and Recast Layer Thickness (RLT).In this study, o examine the process parameters which influence the EDM process during machining of Inconel X-750 alloy using combined techniques of Taguchi and similarity to ideal solutions (TOPSIS).Analysis of variance (ANOVA) was conducted on multi-optimization technique of Taguchi-TOPSIS. ANOVA results identified the best process parameters and their percentages. It developed the mathematical equation on Taguchi-TOPSIS performance characteristics results. The multi optimization results indicated that Ip and Toff are more significant parameters; V, and Ton parameters are less significant. Finally, surface structures were studied at optimized EDM conditions by using scanning electron microscope (SEM).

Experimental Investigation and Parametric Optimization in Abrasive Jet Machining on NICKEL 233 Alloy Using WASPAS

2019 ◽  
Vol 18 (04) ◽  
pp. 549-561
Author(s):  
S. Rajendra Prasad ◽  
K. Ravindranath ◽  
M. L. S. Devakumar
Keyword(s):  
Parametric Optimization ◽  
Removal Rate ◽  
Optimization Technique ◽  
Machining Parameters ◽  
Abrasive Jet Machining ◽  
Process Pressure ◽  
Conflicting Objectives ◽  
Machined Parts ◽  
Optimal Setting ◽  
First Time

Decision of finest machining parameters is very essential factors in any processing of machined parts. This article presents a multi-objective optimization technique, based on WASPAS method toward optimize the machining parameters in abrasive jet machining (AJM) process: pressure, nozzle to tip distance (NTD), and average grain diameter on NICKEL 233 alloy. Three conflicting objectives, Material Removal Rate (MRR), surface roughness (Ra) and taper angle (Ta) are simultaneously considered. The proposed technique weighted aggregated product sum assessment technique is investigation of parametric optimization on AJM process. Its outcome using tool in any ranges of responses in AJM process is the optimal setting of parameters are determined through experiments illustrated. Broad usage of Aerospace industries for NICKEL 233, generating a hole of the machining data first time in this work using AJM will be useful.

Experimental Studies on Enhanced Coagulation of Tail Water

2013 ◽  
Vol 295-298 ◽  
pp. 1478-1481
Author(s):  
Feng Xun Tan ◽  
Jiu Mei Wang ◽  
Dao Ji Wu
Keyword(s):  
Ferric Chloride ◽  
Removal Rate ◽  
Reclaimed Water ◽  
Experimental Studies ◽  
Ammonia Nitrogen ◽  
Raw Water ◽  
Nitrogen And Phosphorus ◽  
Enhanced Coagulation ◽  
Tail Water ◽  
Water Eutrophication

Traditional wastewater treatment methods can no longer remove effectively nitrogen and phosphorus that are the direct murderers of water eutrophication hazard. Enhanced coagulation method was adopted to improve the treatment effect by dosing suitable coagulants and coagulant aids. The raw water was from the reclaimed water in a University. TP and ammonia nitrogen removal of the water had been researched through an enhanced coagulation process with dosing ferric chloride, aluminum sulfate, polymeric ferric chloride, and poly-aluminum chloride (PAC) in this study. The coagulants effects were estimated by determining the removal rate of ammonia nitrogen, TP, COD and turbidity. When dosing the raw water with 80 mg/L PAC, the removal rates of ammonia nitrogen, TP, COD and turbidity are respectively 6.12%, 67.79%, 26.21%, 85.41%. The experimental results can be used as a reference of water treatment in the reclaimed water station.

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