ALUMINUM ALLOY ROLLED SHEET FOR SUPERPLASTIC FORMATION AND LOW IN CAVITATION

摘要

PURPOSE: To produce an Al alloy sheet for superplastic formation and low in cavitation by rolling a cast ingot obtained by adding small quantity of specific element to an Al-Mg base alloy into the sheet material. ;CONSTITUTION: Into molten metal of the Al-Mg base alloy containing 2.0-6.5wt.% Mg as the element for improving the superplastic formability and the strength of the Al alloy and 0.5-100ppm Be as an antioxidant for the molten Al alloy, Ti as crystal grain fining agent for the alloy is added in a small quantity in the shape of base alloy of Al-Ti, etc. In this molten Al alloy, contents of Na, Ca, Ga, Mn, V, Cr, Zr, Si, Cu, Zn, etc., as the elements easily causing the cavity are regulated to the specified small quantities. This molten Al-Mg base alloy is cast and heated to 400-530°C and the hot-rolling and the cold-rolling are executed to make the sheet material. The objective Al alloy sheet for superplastic formation low in cavitation is obtd. by making a ratio of dA/dB to ≥120% wherein dB crystal grain size is at the time of holding at 500°C for 10sec and dA crystal grain size at the time of holding at 500°C for 30min, after completing the superplastic formation.;COPYRIGHT: (C)1995,JPO