7 Tubular Structures: Welding Difficulty and Potential …
243
bodies. Among various aluminium alloys, non-heat treatable alloy AA5083 is extensively used by the automobile industries in making of inner body panels, tanks,
gas cylinders, etc., due to their high formability and high corrosion resistance property [52]. Hence, it is intended to manufacture AA5083 tubes by longitudinal FSW
process and show the suitability of the process by studying its microstructural as well
as mechanical properties.
7.5.1 Experimental Procedure
AA5083-O sheet of 4.6% (weight percentage) of magnesium content has been
selected for experimentation. The uniaxial tensile properties were evaluated by
carrying out tensile test according to ASTM E8M standard along the rolling direction of the sheet with a repeatability of three times. Properties such as yield strength
(YS), ultimate tensile strength (UTS), percentage elongation (% elongation) and
strain hardening exponent (n-value) were evaluated for AA5083 material, and the
obtained average values of these properties from repeated tensile tests are presented
in Table 7.1.
FSW was carried out on the rolled sheets of 2.5 mm thickness and 80 mm outer
diameter. The welding was accomplished on a 6-axis FSW machine (BISS-ITW,
SP-02-05-10). The tool utilized in this welding was made of H13 steel. The tool
design parameters and the process parameters used for these study are given in
Table 7.2. Improper choice of parameters may lead to a defective joint, as shown in
Fig. 7.8. After welding, a non-destructive method was used to visualize the presence
of any defect in the welded tube by using a 3D X-ray microcomputer tomography
(CT) (General Electric, Phoenix v/tome/xs) scanning system. Uniaxial tensile tests
were carried out to determine the strength and ductility of the welded tube. Tensile
Table 7.1 Mechanical properties of AA5083-O sheets of 2.5 mm thickness
Orientation
0.2% YS (MPa) UTS (MPa) % Elongation n-value K-value
Rolling direction (RD) 159.2
330
31.7
0.3
0.76
Table 7.2 Friction stir
welding parameters for
AA5083-O
Tool design parameters
Process parameters
Tool pin geometry
Conical
Rotational speed
(rpm)
1000
Shoulder diameter
(mm)
14
Traverse speed
(mm/min)
30
Pin diameter (mm)
5
Tilt angle (°)
2°
Pin length (mm)
2.2
Plunge depth
(mm)
0.1
243
bodies. Among various aluminium alloys, non-heat treatable alloy AA5083 is extensively used by the automobile industries in making of inner body panels, tanks,
gas cylinders, etc., due to their high formability and high corrosion resistance property [52]. Hence, it is intended to manufacture AA5083 tubes by longitudinal FSW
process and show the suitability of the process by studying its microstructural as well
as mechanical properties.
7.5.1 Experimental Procedure
AA5083-O sheet of 4.6% (weight percentage) of magnesium content has been
selected for experimentation. The uniaxial tensile properties were evaluated by
carrying out tensile test according to ASTM E8M standard along the rolling direction of the sheet with a repeatability of three times. Properties such as yield strength
(YS), ultimate tensile strength (UTS), percentage elongation (% elongation) and
strain hardening exponent (n-value) were evaluated for AA5083 material, and the
obtained average values of these properties from repeated tensile tests are presented
in Table 7.1.
FSW was carried out on the rolled sheets of 2.5 mm thickness and 80 mm outer
diameter. The welding was accomplished on a 6-axis FSW machine (BISS-ITW,
SP-02-05-10). The tool utilized in this welding was made of H13 steel. The tool
design parameters and the process parameters used for these study are given in
Table 7.2. Improper choice of parameters may lead to a defective joint, as shown in
Fig. 7.8. After welding, a non-destructive method was used to visualize the presence
of any defect in the welded tube by using a 3D X-ray microcomputer tomography
(CT) (General Electric, Phoenix v/tome/xs) scanning system. Uniaxial tensile tests
were carried out to determine the strength and ductility of the welded tube. Tensile
Table 7.1 Mechanical properties of AA5083-O sheets of 2.5 mm thickness
Orientation
0.2% YS (MPa) UTS (MPa) % Elongation n-value K-value
Rolling direction (RD) 159.2
330
31.7
0.3
0.76
Table 7.2 Friction stir
welding parameters for
AA5083-O
Tool design parameters
Process parameters
Tool pin geometry
Conical
Rotational speed
(rpm)
1000
Shoulder diameter
(mm)
14
Traverse speed
(mm/min)
30
Pin diameter (mm)
5
Tilt angle (°)
2°
Pin length (mm)
2.2
Plunge depth
(mm)
0.1