Effect of Relatively Insoluble Compounds on β Phase Precipitation in 5083 Aluminum Alloy
Search this article
An investigation has been made into the effect of relatively insoluble compounds on β phase precipitation in Al-Mg series 5083 alloy. Their compounds are usually introduced by additive iron, silicon, manganese, chromium and titanium to the basic alloy in order to improve stress corrosion cracking and to inhibit recrystallization. During solution treatment of β phase, the solution behavior of these insoluble compounds above 500℃ and precipitation behavior of them at 300℃-500℃ are concluded by means of electrical resistivity measurement. There are various insoluble compounds in the aluminum alloy used in this investigation, and of them, C phase-Al (Fe, Mn) Si, α phase-Al_<12> Fe_3Si and E phase-Al_<18> Cr_2Mg_3 were identified by means of X ray diffraction analysis. The precipitation of β phase by aging at 120℃ and 250℃ is affected by the precipitation of these insoluble compounds, and then β phase precipitation is accelerated with decreasing of the amount of these compounds. Consequently, for the welding of 5083 alloy, the distribution, the quantity and the size of β phase and these insoluble compounds are affected by welding procedure and weld heat input. And namely the difference of these microstructures by various thermal cyclings due to welding seems to influence upon sensitivity to stress corrosion cracking of weld joint of this alloy.
- Transactions of JWRI
Transactions of JWRI 7 (2), 173-180, 1978-12