Table 2 Comparison between friction stir welding, laser welding and brazing in welding of Al (1060) and pure Cu

Laser beam welding

Lap welding of Al(1060) to pure Cu by ND:YAG laser (Zuo, et al., 2014)

γ_2-Cu₉Al₄

● γ_2-Cu₉Al₄ had positive influence on the mechanical properties of joint

● Upward convexity

α-Al + θ-CuAl₂

(α + θ) eutectic

α-Al

● Due to the brittle phase θ-CuAl₂, the joint fails by fracture

Lap welding of Al(1050) to pure Cu by FIBRE laser (Sujin, et al., 2014)

Cu₉Al₄

● Due to the brittle phase of CuAl₂ and CuAl, the joint fails by fracture

● Low welding speed leads to crack formation

CuAl₂

CuAl

Friction stir welding

Lap welding of Al(1060) to pure Cu with offset in Al side (Abdollah-zadeh, et al., 2008)

Cu₉Al₄

● AlCu has increased hardness property and strengthened the joint.

● No defects were found.

CuAl₂

CuAl

● Al₂Cu and Al₄Cu₉ improved the mechanical properties, such as ultimate tensile strength and bending property in the joint.

Lap welding of Al(1060) to pure Cu (Tohid, et al., 2010)

Cu₉Al₄

● CuAl₂ and Cu₉Al₄ were formed in the dark area, which was also the reason for defect formations

● Cavity formation due to higher welding speed

CuAl₂

● Formation of micro-cracks due to low welding speeds

Brazing

Lap welding of Al(1060) to pure Cu with various alloys in Zn-Al filler metal (Feng et al. 2012b)

CuAl₂

● CuAl₂ improved the mechanical properties, such as microhardness and shear strength

● Cracks can initiate or propagate if the intermetallic compound is not diluted.

Lap welding of Al(1060) to pure Cu with addition of Ti in Zn-22Al filler metal (Feng, et al., 2013)

CuZn

● CuZn and CuAl₂ had some effect in the mechanical properties of the Al-Cu joint.

● No defects were found.

CuAl₂