Diffusion bonding is a solid state joining process that can be used for both similar and dissimilar materials, including aluminium alloys. The
process works by diffusing atoms across the joint interface at elevated temperatures. Completely autogenous in nature for similar materials, diffusion bonding requires no filler materials although interlayers can be used when joining dissimilar materials. TWI has been developing a proprietary technique enabling the successful diffusion bonding of aluminium, achieving joint strengths comparable to the heat-treated parent material. You can find out more about diffusion bonding (and see a video of the process), here:
https://www.twi-global.com/what-we-do/our-processes/diffusion-bonding
