Micro-Abrasive Water Jet and Micro-WEDM Process Chain Assessment for Fabricating Microcomponents

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Francesco Modica ◽  
Vito Basile ◽  
Francesco Viganò ◽  
Francesco Arleo ◽  
Massimiliano Annoni ◽  
...  
Keyword(s):  
Electrical Discharge Machining ◽  
Water Jet ◽  
Test Case ◽  
Test Cases ◽  
Abrasive Water Jet ◽  
Process Chain ◽  
Machining Time ◽  
Process Chains ◽  
Micro Wedm ◽  
Wedm Process

The capability to manufacture high-precision components with microscale features is enhanced by the combination of different micromanufacturing processes in a single process chain. This study explores an effective process chain that combines micro-abrasive water jet (μ-AWJ) and microwire electrical discharge machining (μ-WEDM) technologies. An experimental spring component is chosen as a leading test case, since fine geometric features machining and low roughness on the cut walls are required. The advantages deriving from the two technologies combination are discussed in terms of machining time, surface roughness, and feature accuracy. First, the performances of both processes are assessed by experimentation and discussed. Successively, different process chains are conceived for fabricating two test cases with different sizes, displaying some useful indications that can be drawn from this experience.

A Method to Reduce Milling Time for Ti-6Al-4V Alloy for Controlled Depth Milling Using Abrasive Water Jet Machining

2011 ◽  
Vol 383-390 ◽  
pp. 1764-1768 ◽  
Author(s):  
Vijay Kumar Pal ◽  
Puneet Tandon
Keyword(s):  
Flow Rate ◽  
Traverse Speed ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Surface Waviness ◽  
Feed System ◽  
Machining Processes ◽  
Machining Time ◽  
Abrasive Water Jet Machining ◽  
Conventional Machining

This Abrasive Water Jet Machining (AWJM) process is usually used to through cut materials which are difficult to cut by conventional machining processes. This process may also be used for controlled depth milling (CDM) of materials. This work primarily focuses on controlling the abrasive flow rate to reduce the time for machining the component. Here, an experimental setup is made with a modified attachment for abrasive feed system to machine for Ti-6Al-4V alloy. The work also investigates the surface morphology, tolerance on depth of machining and surface waviness for the modified setup. With change in mass flow rate of abrasive, the traverse speed is altered and its effects on the machining time are studied. It is observed that traverse speed is an important parameter in the case of CDM for AWJM. It is also shown that surface waviness can be reduced as traverse speed is increased by using modified abrasive feeding system.

Modeling the Machining Parameters of Micro Wire Electrical Discharge Machining of AL 2024 T351

2013 ◽  
Vol 367 ◽  
pp. 466-470 ◽  
Author(s):  
Palani Sivaprakasam ◽  
P. Hariharan
Keyword(s):  
Surface Roughness ◽  
Aluminium Alloy ◽  
Electrical Discharge Machining ◽  
Machining Parameters ◽  
Modeling And Analysis ◽  
Input Variables ◽  
Rsm Model ◽  
Micro Wedm ◽  
Wedm Process ◽  
Al 2024

This paper presents modeling and analysis of machining characteristics of Micro Wire Electro Discharge Machining (Micro-WEDM) process on Aluminium alloy (AL 2024 T351) using the Response Surface Methodology (RSM) and Artificial Neural Network (ANN). The input variables of Micro-WEDM process were voltage, capacitance and feed rate. The surface roughness is considered as a response variable. Experiments were carried out on Aluminium alloy using Central Composite Design (CCD). The RSM and ANN models have been developed based on experimental designs for surface roughness. Analysis of variance (ANOVA) has been employed to test the significance of RSM model. It has been found out that all the three process parameters are significant and their interaction effects are also significant on the surface roughness. Finally predicted values were compared with both modeling methodologies RSM and ANN.

Effect of Abrasive Flow Rate in Milling with Abrasive Water Jet

2011 ◽  
Vol 110-116 ◽  
pp. 196-201 ◽  
Author(s):  
Vijay Kumar Pal ◽  
Puneet Tandon
Keyword(s):  
Flow Rate ◽  
Traverse Speed ◽  
Flaw Detector ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Feed System ◽  
Destructive Testing ◽  
Machining Processes ◽  
Machining Time ◽  
Ultrasonic Flaw

This Abrasive Water Jet Machining (AWJM) process is usually used to cut the materials which are difficult to cut by conventional machining processes. In this work, controlled depth milling (CDM) is done using AWJM. This work primarily focuses on controlling the abrasive flow rate to reduce the time for machining the component. Here, an experimental setup is made with a modified attachment for abrasive feed system to machine stainless steel. The work also investigates the surface morphology, tolerance on depth of machining and surface waviness for the modified setup. With change in mass flow rate of abrasive, the traverse speed may also be altered and its effects on the machining time are controlled. This work also employs Non-destructive Testing (NDT) method i.e. ultrasonic flaw detector to find out internal defects and cracks in the milled material.

Effects of different cutting methods for electrical steel sheets on performance of induction motors

2016 ◽  
Vol 232 (7) ◽  
pp. 1287-1294 ◽  
Author(s):  
Şenol Bayraktar ◽  
Yakup Turgut
Keyword(s):  
Electrical Discharge ◽  
Electrical Steel ◽  
Induction Motors ◽  
Electrical Discharge Machining ◽  
Cutting Parameters ◽  
Water Jet ◽  
Burr Formation ◽  
Wire Electrical Discharge Machining ◽  
Abrasive Water Jet ◽  
Steel Sheets

In this study, by cutting electrical steel stator laminations, one of the most important components of electrical machines by different cutting methods, the effects of these cutting methods on motor efficiency are investigated. As cutting methods, wire electrical discharge machining, punching, laser and abrasive water jet methods are used. Burr formation at the cutting edge leads to short circuits during the steel packaging and causes magnetic losses in steel packages to increase. In addition, depending on the cutting methods, electrical steel lamination insulation layer is damaged as a result of residual and thermal stress formations. These negative conditions cause iron, friction and windage, stator, rotor and additional load losses occurred in the engine to decrease. In order to minimize these cases, electrical steel stator laminations are cut with the cutting parameters determined as a result of pre-cut tests and 5.5-kW induction motors are manufactured. These manufactured motors, according to IEC 60034-2-1-1B method, are subjected to no-load performance tests in addition to six different loading ratios of 25%–50%–75%–100%–115%–125% and constant 50 Hz frequency. As a result of the test measurements, losses occurred in electrical steels cut with abrasive water jet are found to be higher than the other cutting methods. In addition, in terms of the motor performance, the best results are obtained with wire electrical discharge machining cutting method.

scholarly journals Resource and dependency based test case generation for RESTful Web services

2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Man Zhang ◽  
Bogdan Marculescu ◽  
Andrea Arcuri
Keyword(s):  
Web Services ◽  
Domain Knowledge ◽  
Automated System ◽  
Test Case ◽  
Test Cases ◽  
Evolutionary Search ◽  
Sampling Strategies ◽  
Mutation Operators ◽  
On Line ◽  
Restful Web Services

AbstractNowadays, RESTful web services are widely used for building enterprise applications. REST is not a protocol, but rather it defines a set of guidelines on how to design APIs to access and manipulate resources using HTTP over a network. In this paper, we propose an enhanced search-based method for automated system test generation for RESTful web services, by exploiting domain knowledge on the handling of HTTP resources. The proposed techniques use domain knowledge specific to RESTful web services and a set of effective templates to structure test actions (i.e., ordered sequences of HTTP calls) within an individual in the evolutionary search. The action templates are developed based on the semantics of HTTP methods and are used to manipulate the web services’ resources. In addition, we propose five novel sampling strategies with four sampling methods (i.e., resource-based sampling) for the test cases that can use one or more of these templates. The strategies are further supported with a set of new, specialized mutation operators (i.e., resource-based mutation) in the evolutionary search that take into account the use of these resources in the generated test cases. Moreover, we propose a novel dependency handling to detect possible dependencies among the resources in the tested applications. The resource-based sampling and mutations are then enhanced by exploiting the information of these detected dependencies. To evaluate our approach, we implemented it as an extension to the EvoMaster tool, and conducted an empirical study with two selected baselines on 7 open-source and 12 synthetic RESTful web services. Results show that our novel resource-based approach with dependency handling obtains a significant improvement in performance over the baselines, e.g., up to + 130.7% relative improvement (growing from + 27.9% to + 64.3%) on line coverage.

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