HOT CRACKING SUSCEPTIBILITY OF AL-CU-LI AND AL-CU-LI-MN ALLOYS

The effect of Li content (up to 4%), Cu content (up to 5%), and Mn content (up to 1.4%) on the hot cracking susceptibility of Al alloys containing Li was investigated. The usual tests, principally the measurement of crack length in ring castings, were used To evaluate the hot cracking susceptibility of the alloys. The values of linear shrinkage and elongation to failure in the brittle temperature range in the solid-liquid condition were compared. An increase in Li and Cu content ill the AI-Cu-Li system results in a decrease in the hot cracking susceptibility corresponding to a rise in the elongation to failure in the brittle range in the solid-liquid condition. The addition of Mn increases the hot cracking susceptibility associated with a decease in elongation to failure in this temperature range. (C) 1995 The Institute of Materials.