Title: Comparative machinability study of ADI-4h and mild steel using WEDM

Authors: Pranjal Sarma; Dibya Jyoti Borah; Promod Kumar Patowari; Ajay Likhite

Addresses: Department of Mechanical Engineering, Assam Don Bosco University, Guwahati, 781017, Assam, India; Department of Mechanical Engineering, National Institute of Technology Silchar, Silchar, Assam, India ' Department of Mechanical Engineering, National Institute of Technology Silchar, Silchar, Assam, India; Kameng Hydro Electric Project, NEEPCO Ltd., West Kameng, Arunachal Pradesh, India ' Department of Mechanical Engineering, National Institute of Technology Silchar, Silchar, Assam, India ' Department of Metallurgical & Materials Engineering, Visvesvaraya National Institute of Technology, Nagpur, Maharashtra, India

Abstract: Austempered ductile iron (ADI) has been gaining increasing popularity due to its interesting mechanical properties. But its machining by conventional methods is difficult. We report the machining processing response of ADI-4h while processing under wire electric discharge machining (WEDM). The effect of the major WEDM process parameters viz. peak current, pulse-on-time and wire feed on the major response parameters viz. cutting rate, kerf width and surface roughness has been investigated. A comparative machinability study is also carried out with mild steel. Study reveals that ADI shows fairly good machinability under WEDM even though mild steel is more easily machinable. SEM analysis reveals presence of nodular graphite and ausferritic microstructure on the matrix of synthesised ADI-4h and an average recast layer thickness of ~ 6 µm after WEDM processing. The study can help researcher and industries to better understand ADI machinability via WEDM and hence augment its application in various fields.

Keywords: austempered ductile iron; ADI; mild steel; wire electric discharge machining; WEDM; recast layer; machinability; microstructure; austempering.

DOI: 10.1504/IJMMM.2023.129590

International Journal of Machining and Machinability of Materials, 2023 Vol.25 No.1, pp.69 - 88

Received: 27 Sep 2022
Accepted: 01 Jan 2023
Published online: 15 Mar 2023 *