OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
Tool rotation speed, traverse speeds and tool tilt angle were kept constant at 1200 rpm, 20 mm/min and zero
angle respectively. The process variables were, shape of the tool and tool passes on single and double sided. The
axial load was varied by linearly increasing interference between the tool and the base material. In friction stir
welding, the process was used in single pass and double passes. Tool pin length in Single pass FSW and double
pass FSW were 4.7mm and 2.7mm respectively. Time taken for 200mm length was 10min. in case of single pass
weld while time taken for 200mm length in double pass was 20min. In both cases, depth of depression was 0.05
mm and four tools of different pin profiles i.e. straight cylindrical, threaded, triangular and square were used.
3. Results and Discussion
Figure 2 Dimensions of Tensile Specimen
The specimens for tensile test were prepared according to the guidelines of American Society for Testing of
Materials (ASTM) as shown in Figure 2. Cross sectional area of test specimen were 5 x 15 =75 mm 2 . Tensile test
was carried out in 40 KN; electro-mechanical controlled Universal Testing Machine at a room temperature. The
specimen was loaded as per ASTM specifications, so that tensile specimen undergoes deformation. The
specimen finally failed after necking and the load versus displacement was recorded. The ultimate tensile
strength, percentage elongation and joint efficiency were evaluated. In welding, joint efficiency is the ratio of the
strength of a joint to the strength of the base metal, expressed in percentage:
Joint efficiency η = joint strength / parent strength
Specimen
No.
Table 1 Tensile test results of welded specimens in single pass
Ultimate Tensile Strength Percentage Elongation Joint
Efficiency
(%)
Load (KN) Stress
(N/mm 2 )
Elongated
Length (mm)
%
Elongation
S-1 8.4 112 54.4 8.8 95.4
S-3 8.48 113 59.5 19 96.3
S-5 8.96 119.4 52.9 5.8 101.7
S-7 9.52 126.9 58.3 16.6 108.1
Specimen
No.
Table 2 Tensile test results of welded specimens in double pass
Ultimate Tensile Percentage Elongation
Strength
Load Stress Elongated Length %
(KN) (N/mm 2 ) (mm)
Elongation
S-2 8.88 118.4 61.3 22.6 100.9
S-4 8.92 118.9 63.6 27.2 101.3
S-6 10 133.3 55.5 11 113.6
S-8 9.6 128 62.2 24.4 109.9
Joint
Efficiency
(%)
Variation of Ultimate Tensile Strength
Variation Of Percentage Elongation
140
30
Ultimate Tensile Strength
120
100
80
60
40
20
Single Pass
Double Pass
Percentage Elongation
25
20
15
10
5
Single Pass
Double Pass
0
SC SQ TH TR
0
SC SQ TH TR
Tool Profile
Tool Profile
\
Figure 3 Variation of Ultimate Tensile Strength
Figure 4 Variation of Percentage Elongation
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