Correlation between Interface Microstructure and Bond Strength of Al6061/Al6061 HIP-Bonded Plates for Fuel Cladding Application

The effects of hot isostatic pressing (HIP) processing parameters on microstructure and bond strength of Al6061/Al6061 plate interfaces were systemically investigated at the micro- and nanoscale. The HIP bonding of the two aluminum plates was performed at four temperatures: 350°C, 400°C, 450°C, and 560°C. The results reveal the formation of micron scaled Mg2Si precipitate and uniform nano scaled Mg2Al2O5 oxide at the interface. The formation of Mg2Al2O5 is closely associated with the fast bulk diffusion of Mg from the Al matrix to the amorphous Al2O3/Al interface and subsequent reaction between Mg and Al2O3. The highest and lowest bond strengths were observed in samples HIP bonded at 450°C and 350°C, respectively.