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7174 |
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Wednesday, June 22, 2022, Saal Brüssel 9:00 AM Diffusion bonding |
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Development of a novel diffusion bonding technique for Al-alloys |
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James Redman* / TWI Ltd., Great Britain Nick Ludford / TWI, Great Britain |
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Diffusion bonding of Al-alloys is challenging, largely due to the native oxide layer that acts as a diffusion barrier and does not decompose at high temperature. In addition, its susceptibility to deformation at elevated temperatures when under load limits the pressure that can be applied during diffusion bonding. Whilst the use of interlayers has been shown to be successful in achieving a diffusion bonded structure via a transient liquid phase, much less success has been reported for an autogenous process. TWI has recently developed a proprietary technique that enables the successful diffusion bonding of aluminium alloys with the ability to achieve joint strengths comparable to the heat-treated parent material. The technique produces an autogenous joint as no interlayers or melting point suppressants are required. In support of this work, TWI launched a research programme to investigate the application of the technique to different aluminium alloys, with a focus on 2024 and 6082. The strength of the diffusion bonded joints made using TWI’s method were significantly stronger in comparison with a more conventional approach. Mechanical testing data, and micrographs will be presented, along with a discussion around potential applications that include compact heat exchangers, heat sinks, filters, and cryogenics. |