Wrought aluminium alloy with high tensile strength - where amts. of minor elements are controlled to obtain very high notch toughness

摘要

An alloy of the French type A-GS, and similar to USA 6063 or 6060, is made with compsn. (wt. %) 0.3-0.6 Si, 0.4-0.75 Mg, and less than in all cases:- 0.35 Fe, 0.3 Cu, 0.3 Mn, 0.2 Cr, 0.1 Ti, 0.1 Zr, 0.1 each other elements with max. 0.15, and with 0.08-0.4 Mn + 2Cr. In the T5 condition, when the tensile strength is ca. 260 MPa, this alloy has a toughness, Charpy V(K) in J/cm2 (CNT) which is min. 1.5 times the CNT for a conventional A-GS alloy with the same tensile strength (UTS). Pref. alloy contains 0.05-0.25% Cu, 0.08-0.2% Mn, and max. 0.05% Cr, with UTS min. 240 MPa and CNT min. 25 J/cm2. Used esp. in extruded prods. for ladders, suitcases, duck-boards on ships. etc. where conventional alloys possess inadequate notch toughness.