Abstract |
The vacuum brazing of 6061 aluminium alloy with Al-12Si-1Mg-5Cu-xGe(x=0, 10, 20wt.%) braze alloy has been conducted at temperatures ranged 530~570℃ for 60min under brazing pressure of 1MPa to investigate the braze joint microstructure. the joint strength and the wettability of braze alloy. The liquidus temperatures of braze alloys with Ge=0, 10, 20wt.% were 572℃, 558℃ and 541℃, respectively. The wettability of braze alloy was found to be improved with increasing the brazing temperature. Braze joint microstructure was varied with the brazing temperature. Under low brazing temperatures(≤550℃, the silicon and germanium, which are expected to be the elements present in the braze alloy, are observed at the braze joint. On the other hand, these elements were not detected under the brazing temperature of 570℃. This may be due to the diffusion of the elements into 6061 aluminium alloy. The joint strength was found to be increased with increasing the brazing temperature. The maximum joint strength was obtained at 570℃ brazing temperature and its value was 73% of tensile strength of the base metal. |
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Key Words |
Vacuum brazing, 6061Aluminium, Germanium, Al-Si-Mg-Cu-Ge, Wettability, Joint strength |
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