Study Of Defects In Friction Stir Welded AA 5083 （在5083年搅拌摩擦焊接AA研究的缺陷）.pdfVIP

Vidya Joshi et al. : Proceedings of the National Seminar Exhibition on Non-Destructive Evaluation STUDY OF DEFECTS IN FRICTION STIR WELDED AA 5083 BY RADIOGRAPHY, ULTRASONIC AND PHASED ARRAY ULTRASONIC TECHNIQUE 1 1 2 Vidya Joshi , Krishnan Balasubramaniam and Raghu V. Prakash 1 Center for Non Destructive Evaluation and Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India. 2 Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600036, India. ABSTRACT. Friction Stir welding (FSW) is very effective technique mainly to weld the Aluminum alloy which are very difficult to weld by conventional welding method due to occurrence of defects. Even though FSW has some defects, heat input plays a very important role in occurrences of these defects. Heat input during the welding is dependent on the many factors like welding parameter (Rotational Speed and transverse speed), tool design (pin geometry, pin diameter, shoulder diameter etc.) and axial force. In the phased array ultrasonic technique, the excitation of piezo composite element can generate the focused beam with possibility of modifying beam parameters such as angle, focal distance and focal spot size. Thus this technique is useful to detect the randomly located and disoriented defects like crack, porosity etc. Certain variations in welding parameter generate the defects in the weld due to improper heat input. In this paper, the defects in FSW is studied by radiography, conventional ultrasonic and phased