Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 3
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

Recent developments in automation and technology have revolutionized the way products are made. It is directly seen in the evolution of part miniaturization in the sectors such as aerospace, electronics, biomedicine and medical implants. Micromachining is a promising technology to fulfill the need of miniaturization. A review has been done on the micromachining processes such as micro electric discharge machining (micro-EDM) and wire EDM (WEDM), micro electrochemical machining (micro-ECM). Recent literature were studied and categorized in terms of materials, process parameters, performances, product manufactured, and miniature product generation. Starting with brief introduction to micromachining, classifications and applications, technical aspects of discussions from the literature have been presented on key factors such as parameters and the response variables. Important aspects of recast layer, heat effected zone, micro-hardness, micro cracks, residual stress, etc., have been given. A special focus is given to the status of the research on microgear manufacturing. Comparison has been made between other conventional process suitable for micro-gear manufacturing and WEDM. The miniature gear machined by WEDM shows the defect-free microstructure, better surface finish, thin recast layer and improved gear quality parameters such as profile and pitch. Finally, the research gaps and future research directions have been presented.

Go to article

Authors and Affiliations

Tina Chaudhary
Arshad Noor Siddiquee
Arindam Kumar Chanda
Zahid Akhtar Khan
Download PDF Download RIS Download Bibtex

Abstract

Metal matrix composites (MMC) are finding application in many fields such as aerospace and automobile industries. This is due to their advantages such as light weight and low cost. Among all the available non-traditional machining processes, wire electric discharge machining (WEDM) is found to be a suitable method for producing complex or intricate shapes in composite materials. In this study, an aluminum metal matrix composite (AMMC) with 6% and 8% weight (wt) fraction of Al2O3 is prepared through the stir casting process. The fabricated AMMC specimen is machined using WEDM, considering various process parameters such as wt % of reinforcement, gap voltage (Vg), peak current (IP) wire tension (WT) and dielectric pressure (Pd). Output responses such as the machining rate (MR) and surface roughness (Ra) of the slots are analyzed by conducting L18 mixed orthogonal array (OA) experiments. The experiments are analyzed using techniques for order preference by similarity to ideal solution (TOPSIS) and analysis of variance (ANOVA). Based on the analyses, the optimum combination of process parameters for better MR and Ra is as follows: wt % =  6 gm, Vg = 53 V, Ip = 8 A, WT = 11 g, Pd = 13 bar. The optimum level of process parameters for MR and Ra are 1.5 mm/min and 3.648 µm, respectively. Based on ANOVA, the peak current is found to have a significant influence on MR and Ra. Moreover, based on a scanning electron microscope (SEM) image, the presence of micro-ridges, reinforcement, micro-craters, micro-cracks, recast layers and oxide formation are all analyzed on the surface being machined.

Go to article

Authors and Affiliations

T. Mythili
R. Thanigaivelan
Download PDF Download RIS Download Bibtex

Abstract

In this research work, Ti6Al4V alloy material was subjected to electric discharge machining (EDM) and its fatigue life was investigated at low cycle fatigue mode. In order to evaluate the influence of recast layer generated during the machining process on the fatigue life, samples prepared using end milling process were also subjected to similar tests and a comparative analysis is presented. Data were observed in the fully reversed fatigue mode at room temperature using samples fabricated as per ASTM standard E606. The specimen were machined on a spark electric discharge die sink machine which were subjected to fatigue, and the recorded fatigue lives were compared with the fatigue life of end milled specimen. The machined surfaces were examined through optical and scanning electron microscopes, and the roughness was measured with a standard profilometer. It was observed that when the discharge current is augmented, the recast layer formed was in the range of 20 to 70 µm thick. From the results, it is being concluded that fatigue life of the samples fabricated by EDM is less for various load conditions when compared with that of the end milled sample. The milled sample at 160 MPa load exhibited 2.71×105 cycles, which is 64% more when compared to EDM sample.

Go to article

Authors and Affiliations

A. Eakambaram
M. Anthony Xavior

This page uses 'cookies'. Learn more