Significance of liquation cracks in thick section welds in al-mg-si alloy plate

摘要

Study has been carried out on the welding behaviour of heavy section aluminium alloy 6082-T651. Welds were produced usign the metal inert gas (MIG) process in 80mm material, using Al-Mg and Al-Si filler metals. Metallographic examination was carried out, with assessment of heat affected zone (HAZ) toughness by R-curve testing. Butt welds, made using Al-Mg (5356) filler wire, contained HAZ liquation cracks but those made with Al-Si (4043A) filler wire did not. This is consistent with the trends and experience previously established with these filler metals.