The document summarizes a seminar presentation on friction stir welding of high-strength aluminum alloys. It discusses friction stir welding techniques, properties of 7XXX and 2XXX aluminum alloys, applications of friction stir welding in aerospace and other industries, and challenges and opportunities for further research. Friction stir welding is described as a solid-state welding process that was invented in 1991 and provides advantages over conventional welding of aluminum, including fewer defects, no filler required, and improved mechanical properties of the welded joint. The presentation focuses on welding high-strength 7XXX and 2XXX aluminum alloys used in aerospace applications.

1. Metallurgical Operations Seminar
Topic: Friction Stir Welding of High strength Al alloys.
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Subject code: 3152114
Prepared By: (Group B5 - Semester 5 )
● Irfan Pathan - (190130121024)
● Viraj Pithwa - (190130121025)
● Ritul - (190130121027)
Faculty Guide:
● Prof. Hemenkumar Hareshbhai Thakar
Government Engineering College, Gandhinagar
Government Engineering College, Gandhinagar - Metallurgy Department
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2. Contents
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● Project Objective
● Investigation
● Friction stir Welding
● Bottom line
● Why FSW?
● What we meant from “high strength Al alloys”
● Properties of 7XXX & 2XXX aluminium alloys
● Al alloys and welding
● Applications of FSW & Al alloys
● References
● Image credits

3. Project Objective
● The term “welding” is being inhibited in aerospace industry, this solid-state welding
process i.e. FSW made a remarkable entry of “welding” in the aerospace industry. So
our investigation will be about FSW, its applications and scenarios from present and
future perspective.
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4. Investigation
Topic: Friction Stir Welding of High strength Al alloys.
Subtopics
● Friction Stir Welding
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● High strength Al alloys

5. Friction Stir Welding
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6. Friction Stir Welding
Rudimentary aspects:
● Invented by - Wayne Thomas
● Patented in - Europe, the USA, Japan, Australia
● Invented at - The Welding Institute (TWI) Cambridge, U.K.
● Year - 1991
● Industrial use - started in mid 1990s
● Having shortest period - Invention to widespread use
● Classified - solid-state welding process
● Initially applied for Aluminium alloys
● Abbreviated as FSW [1]
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7. Friction Stir Welding
Process:
● Friction stir welding (FSW) is a solid state
joining process.
● Frictional heat generated by a rotating tool is
used to join materials.
● The non-consumable tool, with a profiled probe
or pin and shoulder, is rotated and plunged into
the interface between two work pieces.
● It then traverses along the joint line, causing the
material to heat and soften.
● The shoulder also acts to contain this plasticized
material, which is mechanically mixed to create
a solid phase weld.[1] 7
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8. Process parameters:
1. Tool geometry
○ Governs traverse rate & material flow
○ Uniformity of microstructure & properties
○ Reduce welding force
○ Increase downward augering
○ Increase interface
2. Welding parameters
○ Tool rotation rate(𝝎, rpm)
○ Tool traverse speed(𝜈, mm/min)
○ Tool tilt or angle of spindle
○ Insertion depth
○ Preheating or cooling(material specific)
3. Joint design
○ Almost all types of joints can be produced
○ Convenient - Butt & Lap joints
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Friction Stir Welding
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9. 9
Tool geometry
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10. 10
Tool geometry
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11. 11
Tool geometry
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12. ● Flared-TrifuteTM and A-skewTM pins are suitable for lap, T, and similar welds where joining
interface is vertical to the machine axis.
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Tool geometry
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13. ● The most convenient joint configurations for FSW are butt and lap joints. Apart from butt and
lap joint configurations, other types of joint designs, such as fillet joints (Fig.), are also possible
as needed for some engineering applications.
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Joint Design
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14. ● Material flow - It is widely accepted that material flow within the weld during FSW is
very complex and still poorly understood/documented.
● Tool material and design - Further research is needed to understand the tool wear,
optimization of tool geometry and selection of tool material.
● Tool geometry - At the present stage, tool designs are generally proprietary to individual
researchers and only limited information is available in open literature.
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Critical Research Issues
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15. ● Despite considerable interests in the FSW technology in past decade, the basic physical
understanding of the process is lacking. Some important aspects, including material flow,
tool geometry design, wear of welding tool, microstructural stability, welding of
dissimilar alloys and metals, require understanding and better documentation.
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Bottom Line…..
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16. Why Friction Stir Welding??
As compared to conventional (or fusion) welding processes, FSW :
● Energy efficient
● Versatile in nature
● Environment friendly
● Low number of defects
● No flux required
● No filler required
● No issue of compatibility
● Various types of joints
● Dissimilar metals can be joined
● Easily mechanized
● Considerable improvement in properties
● Termed “green” technology
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17. Contd.....
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18. What we meant from “High Strength Al alloys”
● Predominantly focusing on high strength Al alloys used in aerospace industries
We will consider only the high strength alloys of:
1. 7XXX series
2. 2XXX series
● A four-digit numerical designation system is used to identify wrought aluminium and
aluminium alloys. As shown below, the first digit of the four-digit designation indicates
the group.
● Aluminium, >99.00 %—1XXX. Aluminium alloys grouped by major alloying element(s);
Copper—2XXX; Manganese—3XXX; Silicon—4XXX; Magnesium— 5XXX;
Magnesium and Silicon—6XXX; Zinc—7XXX; Other elements—8XXX; Unused
series—9XXX
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19. Following are some properties of 7XXX and 2XXX aluminium alloys which we have been focusing:
● 7XXX - major alloying element Zinc
● Heat treatable – with ultimate tensile strength of 32 to 88 ksi (kilo pound per square inch)
● These are the aluminum / zinc alloys (zinc additions ranging from 0.8 to 12.0%)
● Comprises some of the highest strength aluminum alloys
● These alloys are often used in high performance applications such as aircraft, aerospace, and
competitive sporting equipment
● 2XXX - major alloying element Copper
● Heat treatable– with ultimate tensile strength of 27 to 62 ksi
● These are aluminum / copper alloys (copper additions ranging from 0.7 to 6.8%)
● These high strength, high performance alloys that are often used for aerospace and aircraft
applications
● They have excellent strength over a wide range of temperature
● Some of these alloys are considered non-weldable by the arc welding processes because of their
susceptibility to hot cracking and stress corrosion cracking; 19
Salient Properties of 7XXX & 2XXX alloys
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20. Al alloys & Welding
From the point of view of conventional welding (fusion welding), Al & its alloys show:
● Brittle welds
● Surface preparation is expensive
● More defects
● Compatibility required
● Handling is difficult
● Joint preparation is limited
● Poor resulting mechanical properties
● Poor solidification microstructure
● Porosity of welds
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21. Applications
FSW with Al alloys, is incorporated:
Aircraft and rocketry:
● Eclipse 500 aircraft
● Boeing Delta Rockets
● C17 Globemaster
Armour and vehicle:
● Advanced Amphibious Assault Vehicle (AAAV)
● Body armour
Ship building:
● MS The World (cruise)
● Finnmarken (cruise)...........
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22. References
1. Friction Stir Welding. (n.d.-b). The Welding Institute. Retrieved June 25, 2021
2. Friction stir welding and processing. (n.d.). Science Direct. Retrieved July 1, 2021
3. Friction Stir Welding of High Strength Aluminium alloys. (2000)
4. FRICTION-STIR WELDING OF HIGH-STRENGTH ALUMINIUM ALLOYS AND A NUMERICAL
SIMULATION OF THE PLUNGE STAGE. (2012, January)
5. Aluminium Alloys for Aerospace Applications. (2017)
6. Understanding aluminium alloys. (n.d.). Alcotec. Retrieved July 7, 2021
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23. 7. [FSW]. (n.d.). TWI Global.
8. [Photograph]. (n.d.).
9. [Image]. (n.d.).
10. [TWI logo]. (n.d.).
11. [Diagram]. (n.d.).
12. [Brittle welds].(n.d.).
13. [Porous welds]. (n.d.).
14. [Eclipse 500]. (n.d.).
15. [Delta rockets]. (n.d.).
16. [C17]. (n.d.).
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Image credits

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Thank you!!
Any Questions?