Influence of Tool Tilt Angle on Material Flow and Defect Generation in Friction Stir Welding of AA2219

  • Suresh Meshram DRDO-Defence Metallurgical Research Laboratory, Hyderabad - 500 058
  • Madhusudhan Reddy DRDO-Defence Metallurgical Research Laboratory, Hyderabad - 500 058
Keywords: Tool tilt angle, Defect, Material flow, Forces.

Abstract

Heat treatable aluminium alloy AA2219 is widely used for aerospace applications, welded through gas tungsten and gas metal arc welding processes. Welds of AA2219 fabricated using a fusion welding process suffers from poor joint properties or welding defects due to melting and re-solidification. Friction stir welding (FSW) is a solid-state welding process and hence free from any solidification related defects. However, FSW also results in defects which are not related to solidification but due to improper process parameter selection. One of the important process parameters, i.e., tool tilt angle plays a critical role in material flow during FSW, controlling the size and location of the defects. Effect of tool tilt angle on material flow and defects in FSW is ambiguous. A study is therefore taken to understand the role of tool tilt angle on FSW defects. Variation in temperature, forces, and torque generated during FSW as a result of different tool tilt angles was found to be responsible for material flow in the weld, controlling the weld defects. An intermediate tool tilt angle (1o-2o) gives weld without microscopic defect in 7 mm thick AA2219 for a given set of other process parameters. At this tool tilt angle, x-force, and Z- force is balanced with viscosity and the material flow strain rate sufficient for the material to flow and fill internal voids or surface defects in the weld.

Author Biographies

Suresh Meshram, DRDO-Defence Metallurgical Research Laboratory, Hyderabad - 500 058

Mr Suresh D. Meshram received BE (Mechanical) from NIT, Surat, in 2000 and MTech (Prod. & Ind. System Engg.) from IIT Roorkee in 2002. He is working as scientist ‘E’ at Defence Metallurgical Research Laboratory (DMRL), Hyderabad. Area of Research mainly includes joining of advance similar and dissimilar materials through process like electron beam welding, friction welding and friction stir welding and characterisation of welded joints. 

 

Madhusudhan Reddy, DRDO-Defence Metallurgical Research Laboratory, Hyderabad - 500 058

Dr G. Madhusudhan Reddy, Scientist ‘H’ obtained PhD in Metallurgical Engineering from Indian Institute of Technology, Madras in 1999. He is heading the metal joining group of DMRL, Hyderabad. He has more than 300 scientific publications to his credit. Dr. Reddy is a Fellow of the ASME (USA), IWS (India) and Institution of Engineers (India). He is member of several professional societies. He has won several awards for his scientific contributions to name a few; Government of India recognised his contributions to the metallurgical sciences by the award “Metallurgist of the Year”. He is also a recepent of DRDO scientist of the year award. 

Published
2018-09-12
How to Cite
Meshram, S., & Reddy, M. (2018). Influence of Tool Tilt Angle on Material Flow and Defect Generation in Friction Stir Welding of AA2219. Defence Science Journal, 68(5), 512-518. https://doi.org/10.14429/dsj.68.12027
Section
Materials Science & Metallurgy