Experimental Investigation on Silicon Powder Mixed-EDM of Nimonic-90 Superalloy

Aiyeshah Alhodaib,Pragya Shandilya,Arun Kumar Rouniyar,Himanshu Bisaria

doi:10.3390/met11111673

Aiyeshah Alhodaib, Pragya Shandilya + Show 2 more

Open Access

https://doi.org/10.3390/met11111673

Copy DOI

Abstract

Powder mixed electrical discharge machining (PM-EDM) is a technological advancement in electrical discharge machining (EDM) processes where fine powder is added to dielectric to improve the machining rate and surface quality. In this paper, machining of Nimonic-90 was carried out using fabricated PM-EDM, setup by adding silicon powder to kerosene oil. The influence of four input process parameters viz. powder concentration (PC), discharge current (IP), spark on duration (SON), and spark off duration (SOFF) has been investigated on surface roughness and recast layer thickness. L9 Taguchi orthogonal and grey relational analysis have been employed for experimental design and multi-response optimization, respectively. With the addition of silicon powder to kerosene oil, a significant decrease in surface roughness and recast layer thickness was noticed, as compared to pure kerosene. Spark on duration was the most significant parameter for both surface roughness and the recast layer thickness. The minimum surface roughness (3.107 µm) and the thinnest recast layer (14.926 μm) were obtained at optimum process parameters i.e., PC = 12 g/L, IP = 3 A, SON = 35 μs, and SOFF = 49 μs using grey relational analysis.

Highlights

Nimonic-90 is a nickel-cobalt-chromium based superalloy used at high temperature applications in aerospace, defense, marine, nuclear, and power plant industries
This paper aims to investigate the influence of process parameters viz. powder concentration (PC ), discharge current (IP ), spark on duration (SON ), and spark off duration (SOFF ) on the surface roughness (SR) and recast layer thickness (RLT)
ED machining of Nimonic-90 superalloy is performed by mixing the silicon powder in kerosene oil

Summary

Introduction

Nimonic-90 is a nickel-cobalt-chromium based superalloy used at high temperature applications in aerospace, defense, marine, nuclear, and power plant industries. Nimonic-90 superalloy is used for the manufacturing of components including exhaust re-heaters, ring sections, jet engines, turbine blades, and hot working tools This is due to its excellent mechanical properties, namely its good corrosion resistance and high creep, rupture strength, and chemical resistance. Advanced machining processes, namely laser beam, abrasive water jet, electron beam, and electrical discharge machining (EDM), were employed to overcome such difficulties faced by conventional machining. Among these non-conventional machining processes, EDM offers reasonable attention on the machining of Nimonic-90, regardless of material hardness and complex profiles with higher automation [5,6]. Powder particles arrange in a chain form, causing a short circuit, and leading to early explosion

Objectives

Methods

Results

Conclusion