5A06 铝合金多孔型结构扩散连接工艺研究

To meet the application requirements of porous aluminum alloy components, the diffusion bonding process of 5A06 aluminum alloy channel joints was investigated. Based on vacuum diffusion bonding experiments, the effects of temperature, pressure and Cu foil thickness on the diffusion bonding of 5A06 aluminum alloy were analyzed. Compared without the interlayer, the beneficial effects of Cu interlayer on optimizing the diffusion bonding process parameters and improving the interface structure were verified, and the optimal diffusion bonding parameters for 5A06 aluminum alloy porous structure were determined. The results show that the Cu foil interlayer can promote sufficient diffusion reaction and improve the shear strength of joint. At an appropriate temperature, it can react with the matrix to form a single Al₂ CuMg phase, which effectively avoids interfacial defects such as cracks caused by the mutual restriction of multiple hard and brittle phases during bonding. However, an excessively thick Cu foil leads to the enrichment of new phases near the weld grain boundaries and reduces the uniformity of the interfacial microstructure. In addition, excessively high temperature and pressure result in a significant reduction in the thickness of the porous joint, making it difficult to maintain the channel geometry. Considering the interfacial microstructure, mechanical properties and deformation degree comprehensively, the optimal process parameters for 5A06 aluminum alloy channel joints are determined as 520 ℃ / 1 MPa / 10 μm Cu foil. Under these parameters, the porous joint exhibits low deformation and the shear strength can reach 130 MPa.