Process optimisation of hot extrusion of aluminium 6061 alloy using bridge-die

Abstract

Porthole-die extrusion has the great advantage of forming hollow section tubes that are difficult to produce by conventional extrusion with a mandrel on the stem. Due to the complicated structure of the die assembly, the extrusion of hollow section tubes has been investigated experimentally. During the hot extrusion process of aluminium alloy 6061, the process parameters significantly affect the mechanical properties of extruded products. For better extruded components, these process parameters need to be optimised. An experimental investigation and analysis has been carried out to optimise the billet temperature, mandrel length, convex die angle and tooling temperature on porthole-die hot-extruded aluminium alloy 6061 tubes under extrusion ratio of24.03. During the experiments the above parameters were varied and Taguchi’s optimisation approach was applied to obtain an optimal setting of parameters. From the experimental results and further analysis, it is concluded that under 95% confidence interval the billet temperature 420 °C, mandrel length 8 mm, convex die angle 105° with three-channel die method gave the minimum extrusion load, while the highest tensile strength was obtained with billet temperature 410 °C, mandrel length 11 mm, tooling temperature 400 °C. However, the most significant process parameters responsible for minimum extrusion load and maximum tensile strength with their percent contribution were convex die angle 97.83% and mandrel length 81.16%, respectively.

Keywords:

• Porthole-die
• hot extrusion tube
• aluminium alloy 6061
• mechanical properties
• Taguchi method orthogonal array

Additional information

Notes on contributors

R Prabhu

R. Prabhu is currently working at Adhiparasakthi Engineering College, Melmaruvathur, Tamil Nadu, India, as an Associate Professor in the Mechanical Engineering Department. He received his Bachelors Degree in Mechanical Engineering from Madras University, Chennai, India. He obtained his Masters Degree in Production Technology from Annamalai University, Chidambaram, India. He has submitted his PhD thesis to Sri Chandrashekarendra Saraswathi Viswa Maha Vidyalaya University, Kanchipuram, India. His professional interests include design of jigs, fixtures, CIM, modelling and analysis, forming, and parameter optimisation of manufacturing tools. He was Assistant Professor, Senior Lecturer and Lecturer in the Mechanical Engineering Department at Adhiparasakthi Engineering College, Melmaruvathur, India. He also served as Lecturer in the Mechanical Engineering Department at VRS College of Engineering & Technology, Arasur, Villupuram, India. He also worked as Assistant Engineer of Special Mining Equipments at Vasavi Engineering Corporation, Neyveli Mines-II.

T Ganapathy

Dr T. Ganapathy is presently working as Principal of St. Anne’s College of Engineering & Technology, Panruti, Tamil Nadu, India. He received his Bachelors Degree in Mechanical Engineering from Bharathiar University, Coimbatore, India, and Masters Degree in Energy Technology from Pondicherry University, Pondicherry, India. He received his Doctoral Degree in Mechanical Engineering from Indian Institute of Technology Roorkee, India. His areas of research includes alternative fuels for diesel engines, biodiesel, combustion and emissions, optimisation techniques, and material science. He has more than 20 years of experience in academic and research. He was a Professor of Mechanical Engineering at Adhiparasakthi Engineering College, Melmaruvathur, India. He served as Expatriate Lecturer in Mechanical Engineering Department at Arba Minch University, Ethiopia, under UNDP. He also served as Assistant Professor, Selection Grade Lecturer, Senior Lecturer and Lecturer in Mechanical Engineering Department of VRS College of Engineering & Technology, Arasur, Villupuram, India. He worked as Lecturer at Elumalai Polytechnic, Villupuram, India. He is a recipient of the award of Ministry of Human Resources and Development Fellowship for his doctoral research at IIT Roorkee, India.

V S K Venkatachalapathy

Dr V. S. K. Venkatachalapathy is now working as Principal of Sri Manakula Vinayagar Engineering College, Madagadipet, Pondicherry, India. He received his Bachelors Degree in Mechanical Engineering, Masters Degree in Production Engineering and Doctoral Degree in Mechanical Engineering from Anna University, Chennai, India. He has more than 24 years of experience in academic and research. He was a Professor and Head of Mechanical Engineering Department at VRS College of Engineering & Technology, Arasur, Villupuram, India. He served as Assistant Professor, Senior Lecturer and Lecturer at Adhiparasakthi Engineering College, Melmaruvathur, India. He also worked as Research Associate in a sponsored project at Mechanical Engineering Department, Anna University, Chennai, India. He has published more than 50 papers in refereed journals and conference proceedings at international and national level. He has supervised more than three doctoral theses. He is member of various professional bodies such as American Society of Metals, Indian Society of Technical Education, Solar Energy Society of India, Science and Technology for Knowledge Society, Computer Society of India, the Institution of Engineers, and Indian Welding Society.