Regular Article

Effect of flyash on the surface hardness of AA 6063 using GTA as a heat source

Department of Mechanical Engineering, Amrita School of Engineering, Coimbatore Amrita Vishwa Vidyapeetham, Amrita University, Amrita Nagar (PO), Ettimadai, 641112 Coimbatore, Tamilnadu, India

^* Email: a_shanmugasundaram@cb.amrita.edu

Received: 21 May 2016
Received in final form: 24 March 2017
Accepted: 28 June 2017

Abstract

Effect of reinforcing flyash to the surface of AA 6063 aluminium alloy using Gas Tungsten Arc (GTA) as a heat source and corresponding hardness variation have been studied. Heat source parameters such as current, electrode tip distance and tip angle are kept as constant and the work speed is varied. Reduction of microhardness is observed in the fusion zone after applying the heat on the specimens without flyash. Flyash of 38, 75 and 90 µm particle sizes were deposited onto the surface of AA 6063 alloy specimen using GTA as a heat source. The thickness of the modified layer is found to be 1.02 mm. The addition of flyash increased the hardness to that of the base metal. Further artificial aging increased the microhardness of the modified surface layer significantly compared to the base metal. The resulting modified layer was characterized by energy dispersive x-ray spectrometry (EDX) and X–ray diffraction (XRD) technique.