JISHNU SAJEEV

SNEHITH N
KASHINATH KRISHNA V 

ABHAY SASI C P

Friction Stir Welding (FSW) is a solid-state joining process that has revolutionized the
ficld of metal fabrication since its invention by The Welding Institute (TWI) in 1991.
Unlike conventional fusion welding techniques, FSW does not involve melting of the base
materials; instead, it relies on mechanical stirring and frictional heat to produce a strong.
defect-free joint. In this process, a non-consumable rotating tool with a specially designed
pin and shoulder is inserted at the interface of the workpieces. The friction between
the tool and materials generates localized heat, softening the metal without reaching its
melting point. As thc tool traverses along the joint linc, plastic deformation and material
flow occur, resulting in a metallurgically bonded solid-phase weld.
FSW is widely used in aerospace, automotive, marine, and railway industries due
to its ability to join lightweight materials such as aluminum and its alloys, magnesium,
and copper with excellent mechanical and metallurgical properties. The process offers
several advantages, including low distortion, absence of solidification defects, refined
grain structure, and high joint eficiency. Additionally, it enables the joining of dissimilar
materials, which is challenging for conventional welding techniques. The quality of the
weld depends on key process parameters such as tool rotational speed, traverse speed,
axial force, and tool geometry. Optimization of these parameters is cssential to achieve
superior joint performance and minimize defects like tunnel voids or surface irregularities.
Recent research focuses on cxtending FSW applications to high melting point
materials like steel and titanium, improving tool materials, and implementing robotic
and underwater FSW techniques. Overall, FSW represents a sustainable, cnergy
efhcient, and high-quality welding process that continues to play a crucial role in nmodern
manufacturing and advanced material engineering.