Direct diffusion bonding of 1060Al processed by surface activation with various doses of Ar ion bombardment

Abstract

In this work, the microstructure and properties of the 1060Al surface after bombardment with different doses of Ar ion and the evolution rule of the quality of the subsequent solid-state diffusion bonded joints have been investigated in detail. The results showed that the oxide layer could be removed completely at an appropriate ion bombardment dose (2 × 1018ion/cm, while kept the same energy of 1 keV), the roughness of the surface was also reduced, crystal defects such as dislocation loops formed near the surface, all of the above factors were beneficial for diffusion bonding. Well-bonded joints with a bonding ratio of ∼97.7% and a shear strength of ∼45.9 MPa could be obtained even at lower process parameters (450 °C/90 min, 5 MPa). When the bombardment dose was too low, the residual oxide film and the rough surface were not conducive to atomic diffusion at the interface, resulting in the unbonded defects in the joint. While the irradiated expansion of the 1060Al surface occurred when the bombardment dose was too high, and the bulges would crack under pressure. In both cases, it could not obtain a well-bonded interface, the joints showed a lower shear strength.