Large-scale diffusion bonding of aluminium alloy without interlayers: Mechanical performance and interface quality

Genuine diffusion bonding (DB) of aluminium alloys on a practically usable scale has yet to be fully demonstrated for industrial applications. This study presents the successful fabrication of large-sized DB samples of AA6061 aluminium alloy without interlayers and evaluates the mechanical integrity of the bonded interfaces through tensile and shear tests. Notably, tensile testing – seldom performed in previous literature due to limited sample dimensions – was conducted on specimens extracted from the diffusion-bonded assemblies. The results reveal that under optimised process conditions, the bonded interface can attain mechanical performance comparable to the monolithic parent alloy, indicating near-100% bonding efficiency.