Aluminum alloy vehicular member

Aluminum alloy products particularly for automotive applications, e.g. panel members, may be produced from a body of aluminum base alloy consisting essentially of, by weight, 0.5 to 0.85% Si, 0.25 to 0.55% Mg, 0.05 to 0.4% Fe, 0.75 to 1.1% Cu, the balance essentially aluminum and incidental elements and impurities. The alloy body may be homogenized at a temperature in the range of 900.degree. to 1100.degree. F. and thereafter worked into a wrought product such as sheet which may be continuously solution heat treated and quenched and aged to a T4 condition prior to forming into vehicular panel members, for example.

EXAMPLE 
An aluminum alloy consisting of, by weight, 0.61% Si, 0.40% Mg, 0.93% Cu, 
0.13% Fe, 0.06% Mn, the balance essentially aluminum, was cast into ingot 
suitable for rolling. The ingot was homogenized in a furnace at a 
temperature of 1040.degree. F. for 4 hours and then hot rolled into a 
sheet product about 0.14 inch thick which was cold rolled into a sheet 
thickness of 0.035 inch. The sheet was solution heat treated in a 
continuous heat treating furnace at a temperature of 940.degree. F. for a 
furnace time in the neighborhood of about 1-2 minutes and then quenched 
with cold water spray to room temperature. Properties including transverse 
yield strength and formability of the sheet in the aforesaid condition 
followed by material aging to a step property level referred to as the T4 
temper are set forth in the Table. For purposes of artificial aging, the 
sheet as treated for one hour at a temperature of 400.degree. F. to 
increase its strength. The properties of the sheet in this condition 
referred to as the T6 temper are also listed in the Table. The yield 
strength values for sheet products referred to herein are typically based 
on specimens taken in the transverse direction, the direction across a 
sheet and normal to the direction of rolling. These values are sometimes 
less than those for the longitudinal specimens since the latter can be 
higher because of stretching which is effected in the longitudinal 
direction and increase the longitudinal strength values more than the 
transverse values. 
TABLE 
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Sheet A 
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Temper T4 T6 
Yield Strength 19.8 38.0 
Tensile Strength 38.2 45.5 
Formability 0.388 -- 
Bendability No orange -- 
peel or 
cracking 
Elongation (%) 28 13.5 
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From this example it can be seen that the sheet, in accordance with the 
invention, provides a high degree of formability as measured by Olsen cup 
height. 
While the invention has been described in terms of preferred embodiments, 
the claims appended hereto are intended to encompass other embodiments 
which fall within the spirit of the invention.