1. 1050-H24铝合金的搅拌摩擦焊接 FRICTION STIR WELDING OF AA1050-H24
刘会杰
哈尔滨工业大学
现代焊接生产技术国家重点实验室

2. Base material used in experiments 1050-H24铝合金的搅拌摩擦焊
Chemical compositions of
1050 -
H24 aluminum alloy Al Si Fe Cu Mg V Ti
99.58
0.04
0.32
0.02
0.01
Mechanical properties of 1050-H24 aluminum alloy
Tensile
strength
0.2% proof
Elongation
Hardness
106 MPa
68 MPa
18.6 %
40.2 HV

3. Experimental equipment
1050-H24铝合金的搅拌摩擦焊

4. Tool dimensions and welding parameters
1050-H24铝合金的FSW ——单面焊
Single-sided FSW

5. 1050-H24铝合金的FSW ——单面焊
Single-sided FSW
Weld appearance

6. 1050-H24铝合金的FSW ——单面焊 Single-sided FSW Tensile samples 5 5 5
Welding Direction
Rotating Direction
Single-sided FSW
Tensile samples

7. Tensile properties of joints
1050-H24铝合金的FSW ——单面焊
Tensile properties of joints
Single-sided FSW

8. Fracture locations of joints
1050-H24铝合金的FSW ——单面焊
400 mm/min
800 mm/min
R Side
A Side
100 mm/min
w = 1500 rpm
w = 1500 rpm
Single-sided FSW
v = 200 mm/min
2000 rpm
1000 rpm
800 rpm
R Side
A Side
v = 200 mm/min
Fracture locations of joints

9. Variation in tensile properties with revolutionary pitch
1050-H24铝合金的FSW ——单面焊
Single-sided FSW
Variation in tensile properties with revolutionary pitch

10. Cross sections obtained at the different revolutionary pitches
1050-H24铝合金的FSW ——单面焊
A Side
R Side
(a)
(d)
(c)
(b)
v = 200 mm/min, d = 0.13 mm/r
v = 200 mm/min, d = 0.25 mm/r
w = 1500 rpm, d = 0.07 mm/r
w = 1500 rpm, d = 0.53 mm/r
2mm
Single-sided FSW
Cross sections obtained at the different revolutionary pitches

11. 1050-H24铝合金的FSW ——单面焊 Single-sided FSW
(a)Constant rotation speed
(b) Constant welding speed
w = 1500 rpm
v = 200 mm/min
Single-sided FSW
Hardness distributions of the joints

12. Heterogeneity of properties
1050-H24铝合金的FSW ——不均匀性
Welding Direction
Rotating Direction
Heterogeneity of properties
Lower part
Middle part
Upper part
Tensile samples

13. 1050-H24铝合金的FSW ——不均匀性 Heterogeneity of properties
Mechanical properties of different component parts

14. 1050-H24铝合金的FSW ——不均匀性 Heterogeneity of properties
d = 0.07 mm/r
Upper Part
R Side
A Side
Middle Part
Lower Part
d = 0.53 mm/r
R Side
A Side
Fracture locations of different component parts

15. 1050-H24铝合金的FSW ——不均匀性 Heterogeneity of properties
R Side A Side
(a)
Heterogeneity of properties
R Side A Side
(b)
R Side A Side
(c)
Hardness distributions in the different component parts

16. Single-sided FSW — Conclusions
1050-H24铝合金的FSW ——单面焊
(1) In the FSW of 1050-H24 aluminum alloy, the optimum welding parameters can be determined from the relations between the tensile properties and the welding parameters, and the maximum tensile strength of the joints is equivalent to 80% that of the base material.
(2) When the welding parameters deviate from the optimum values, the tensile properties of the joints deteriorate and the fracture locations of the joints clearly change.
(3) The different component parts of the joint possess different mechanical properties, and the welding parameters have different effects on their mechanical properties. In the three component parts of the joint, the middle part is weakest and the upper part is strongest in mechanical properties.
(4) The fracture locations of the different component parts of the joint are different from one another, but all the fracture locations occur on the advancing side or in the weld center and are affected by the welding parameters.

17. Schematic illumination of two-sided FSW process
1050-H24铝合金的FSW ——双面焊

18. Designation of welding tool and parameters
1050-H24铝合金的FSW ——双面焊
Two-sided FSW

19. Initial welding speed = 400 mm/min
1050-H24铝合金的FSW ——双面焊
Initial welding speed = 400 mm/min
Two-sided FSW
2 mm RS AS
(c)
200 mm/min
(d) RS AS
2 mm
Defect
600 mm/min

20. Final welding speed = 400 mm/min
1050-H24铝合金的FSW ——双面焊
Final welding speed = 400 mm/min
Two-sided FSW

21. Initial and final welding speed = 400 mm/min
1050-H24铝合金的FSW ——双面焊
Initial and final welding speed = 400 mm/min
Two-sided FSW
(c)
Minimum
hardness
No.2 samples: same
welding direction
No.5 samples: opposite
welding direction

22. 1050-H24铝合金的FSW ——双面焊 Two-sided FSW
Initial and final welding speed = 400 and 200 mm/min, respectively
Two-sided FSW
(c)
Minimum
hardness
No.1 samples: large-size
welding tool
No.6 samples: small-size
welding tool

23. Two-sided FSW — Conclusions
1050-H24铝合金的FSW ——双面焊
(1) The welding parameters, welding direction and tool size have certain effects on the tensile properties and fracture locations of the two-sided friction-stir-welded 1050-H24 joints. Under the optimum welding conditions, the tensile properties of such joints are not yet higher than those of the single-sided welded joints.
(2) The mechanical properties of the 1050-H24 joints cannot be improved by so-called two-sided FSW process. The reason for this may be explained by the softening effect resulted from reheating to the joints.