This document presents a study on the effect of friction stir welding on the mechanical properties and formability of thin aluminum blanks. It describes the experimental setup used, including the milling machine, fixture, backing plate, tools, and specimen. It details the experimental procedure and process parameters tested. Results are presented on hardness values, microhardness profiles, and limiting dome height tests of the welded samples. The conclusion is that hardness is higher on the advancing side of the weld due to more grain refinement, and that further tensile tests need to be done to fully analyze formability.

1. A
Presentation on
Effect of Friction Stir Welding on mechanical properties and
formability of thin commercial Al blanks
Submitted by
Manish Singh (2011MEP3270)
Under the guidance of
Dr. S. Aravindan and Dr. D. Ravi Kumar
Department of Mechanical Engineering
Indian Institute of Technology, Delhi

2. Contents
1. Introduction
2. Experimental setup
3. Experimental procedure
4. Results and discussion
5. Conclusion
6. Gantt chart
7. References

3. Friction stir welding : FSW is a solid–state, hot–shear
joining process in which a rotating tool with a shoulder moves
along the butting surfaces of two rigidly clamped plates placed on
a backing plate as shown in Fig.
Schematic illustration of the Friction Stir Welding process[1].

4. Friction Stir Welding Set up:
1. Vertical Milling machine
2. Fixture
3. Backing Plate
4. Tool
5. Specimen

5. Fixture:

6. Backing Plate
Backing plate (200X100X8 mm) used in FSW process.

7. FSW Tools
Table 1- Tools Used for Welding
Tool Tool 1 Tool 2 Tool 3
Tool
Figure
Tool pin
8 mm 12 mm 16 mm
Diameter
Tool dimensions Values
Shoulder length (mm) 10
Shank diameter (mm) 19.95
Shank length (mm) 57

8. Specimen:
Specimen (170X50X1.7 mm).

9. Experimental procedure
No
Yes

10. Process parameter
The welding was carried out by using the selected variations of parameters as shown
in Table1 which is obtained by Taguchi’s orthogonal array method for minimizing
the number of experiments.
Welding Run Rotational Welding speed Tool diameter Depth of
No. speed (rpm) (mm/min) (mm) plunging (mm)
1 450 80 8 0.2
2 450 160 12 0.2
3 450 250 16 0.2
4 560 160 8 0.2
5 560 250 12 0.2
6 560 80 16 0.2
7 710 250 8 0.2
8 710 80 12 0.2
9 710 160 16 0.2

11. Table 4- Vickers Hardness values of all samples with respect to weld region
Distance from Centre
Line
Welding Run 1 Welding Run 4 Welding Run 7
Sample no.
-7 44.9 44.4 45.6
-6 43.4 44.6 43.6
-5 43.32 42.4 42.6
-4 40.7 41.7 41.5
-3 42.5 40.1 40.6
-2 39.8 40.8 37.6
-1 37.9 39.3 37.5
0 41.8 38.1 36.3
1 38.6 36.9 38.3
2 41.2 36.8 40.0
3 42.4 39.5 41.3
4 42.6 41.5 41.6
5 42.8 41.1 41.9
6 43.8 40.6 42.1
7 44.2 44.6 43.8

12. Microhardness profile of welded samples

13. Limiting Dome Height Test of FS Welded Samples
Welding
Weld Run No. LDH Test Samples LDH (mm) Remarks
parameters
Rotational Failure
Speed = 450 occurs from
11.04
rpm weld centre
Welding line
Run No. 1 Speed = 80
mm/min Failure
Shoulder occurs from
13.76
Diameter = 8 TMAZ/HA
mm Z

14. Welding
Weld Run No. LDH Test Samples LDH (mm) Remarks
parameters
Rotational
Speed = 560 Failure occurs
rpm 12.72 from
Welding TMAZ/HAZ
Speed = 160
Run No. 4 mm/min
Shoulder
Failure occurs
Diameter =
11.32 from Weld
8 mm
centre line
Welding
parameters

15. Welding LDH
Weld Run No. LDH Test Samples Remarks
parameters (mm)
Failure
Rotational
occurs in
Speed = 710 12.04
Weld centre
rpm
line
Welding
Run No. 7 Speed = 250
mm/min Failure
Shoulder occurs from
Diameter = 8 14.28
Weld centre
mm line

16. Tensile test
Weld Nugget
Tensile Sample
along the Weld
Weld Centre
Line
Tensile Sample
Transverse to
the Weld
Hardness Sample
Transverse to the Weld

17. Conclusion:
1. Hardness in advancing side is more than the retreating side in
HAZ and TMAZ because the grain refinment is more in
advancing side than retreating side.
2. From the LDH tests, it is observed that LDH in run 7(710
rpm, 250 mm/min, 8mm) is higher than the LDH in run
1(450 rpm, 160 mm/min, 8mm) and run 4(560 rpm, 160
mm/min, 8mm). As formability strongly depends on
mechanical properties of the welded blank, further tests
(tensile tests and LDH tests) have to be carried out to draw
the conclusions.
3. In LDH tests the failure occurred in the weld region in some
samples and in HAZ/TMAZ in other samples.

18. Work done till now Time
1. To study the literature and see the
various aspect of project 25thJuly - 15th February
2. Weld specimen preparation by friction stir
welding process. 10th January- 25th January
3. To study the micro-structure of weld specimen 25th January- 5th February
4. Performance of micro hardness test
and LDH test. 5th February - 18th February
5. Report writing. 15th February -20th February
Work to be done
1. Weld specimen for remaining runs is going to be prepared.
2. LDH tests and microhardness tests will be performed after that.

19. Gantt chart
Time June Jul. Aug. Sep. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May
Activity
Literature
review
Setup
preparation
TWBs
preparation by
FSW
Sample
preparation &
Mechanical
testing
Forming test
Report
writing

20. References
1. R. Nandan ,T. DebRoy ,H.K.D.H. Bhadeshia, Recent advances in friction-stir welding – Process, weldment
structure and properties, Progress in Materials Science 53 (2008) 980–1023.
2. J. Jeswiet, M. Geiger, U. Engel, M. Kleiner, M. Schikorra, J. Duflou, R. Neugebauer, P. Bariani, S. Bruschi,
Metal forming progress since 2000, CIRP Journal of Manufacturing Science and Technology 1 (2008) 2–17.
3. Amir Abbas Zadpoor, Jos Sinke, Rinze Benedictus, Raph Pieters, Mechanical properties and microstructure of
friction stir welded tailor-made blanks, Materials Science and Engineering A 494 (2008) 281290.
4. Sushanta Kumar Panda, D. Ravi Kumar, Improvement in formability of tailor welded blanks by application of
counter pressure in biaxial stretch forming, journal of materials processing technology 2 0 4 ( 2 0 0 8 ) 70–79.
5. R Ganesh Narayanan1 and K Narasimhan, Predicting the forming limit strains of tailor-welded blanks, The
manuscript was received on 17 April 2008 and was accepted after revision for publication on 20 June 2008.
6. M.Sivashanmugam, S.Ravikumar, T.Kumar, V.Seshagiri Rao, D.MuruganandamA Review on Friction Stir
Welding for Aluminium Alloys, 978-1-4244-9082-0/10/$26.00 ©2010 IEEE
7. D.M. Rodrigues, A. Loureiro, C. Leitao, R.M. Leal, B.M. Chaparro, P. Vilaça, Influence of friction stir welding
parameters on the microstructural and mechanical properties of AA 6016-T4 thin welds, Materials and Design
30 (2009) 1913–1921.
8. Wonoh Lee, Kyung-Hwan Chung, Daeyong Ki, Junehyung Kim, Chongmin Kim, Kazutaka Okamoto, R.H.
Wagoner, Kwansoo Chung, Experimental and numerical study on formability of friction stir welded TWB
sheets based on hemispherical dome stretch tests, International Journal of Plasticity 25 (2009) 1626–1654.
9. Daeyong Kim, WonohLee, JunehyungKim, ChongminKim, KwansooChung, Formability evaluation of friction
stir welded 6111-T4 sheet with respect to joining material direction, International Journal of Mechanical
Sciences 52 (2010) 612–625.
10. Kwansoo Chung, Wonoh Lee, Daeyong Kim, Junehyung Kim, Kyung-Hwan Chung, Chongmin Kim,
Kazutaka Okamoto, R.H. Wagoner, Macro-performance evaluation of friction stir welded automotive tailor-
welded blank sheets: Part I – Material properties, International Journal of Solids and Structures 47 (2010)
1048–1062.