Battery tray bottom for electric vehicles
The invention relates to battery trays for electric or hybrid vehicles. The bottoms of the battery trays are made of a thin sheet of aluminum alloy having a modulus of elasticity higher than 77 GPa in order to optimize thickness thereof while ensuring resistance to intrusion. The invention also relates to a thin sheet of 4xxx series aluminum alloy whose modulus is higher than 77 GPa and whose yield strength Rp 0.2 is higher than 295 MPa.
1 . A thin sheet made of 4xxx alloy for a battery tray bottom made of aluminum alloy whose modulus of elasticity is at least 77 GPa and whose yield strength Rp0.2 is at least 315 MPa in T6 condition.
2 . The thin sheet according to claim 1 , whose 4xxx alloy contains scrap.
3 . The thin sheet according to claim 1 , wherein a carbon footprint of manufacture of a foundry plate for manufacture of the thin sheet is less than 4 tons of CO 2 per foundry plate.
4 . The thin sheet according to claim 1 , comprising a composition of 4xxx alloy, in % by weight,
Si: 10-14,
Mg: 0.05-0.8,
Cu: 0.2-2.0,
Fe: <=0.5,
Mn: <=0.5, optionally at least one element selected from among Na, Ca, Sr, Ba, Y and Li, the amount of said element if selected being 0.01-0.05 for Na, Ca, Sr, Ba, Y and 0.1-0.3 for Li,
Sb: <=0.05,
Cr: <=0.1,
Ti: <=0.2,
other elements <0.05 each and <0.15 in total, the remainder being aluminum.
5 . The thin sheet according to claim 4 , comprising insoluble Mg2Si precipitates.
6 . The thin sheet according to claim 4 , wherein the Si content: 11-13% by weight.
7 . The thin sheet according to claim 4 , wherein the Cu content is at least 0.25% by weight.
8 . The thin sheet according to claim 4 , wherein the Fe content is at least 0.10%.
9 . The thin sheet according to claim 4 , wherein the Mn content: 0.05-0.2% by weight.
10 . The thin sheet according to claim 4 , wherein the Mn content: <0.05% by weight.
11 . The thin sheet according to claim 4 , wherein the Sr content: 0.01-0.05% by weight.
12 . The thin sheet according to claim 4 , wherein the Cr content: 0.01-0.05% by weight and/or the Ti content 0.01-0.15% by weight.
13 . The thin sheet according to claim 4 , wherein the Cu content is 0.4-0.8% by weight.
14 . The thin sheet according to claim 1 , comprising a yield strength in T6 condition of at least 320 MPa.
15 . The thin sheet according to claim 1 , wherein the 4xxx alloy contains chips or wastes originating from end-of-life vehicles.
16 . The thin sheet according to claim 1 , wherein the 4xxx alloy contains at least 50% by weight of scrap.
17 . The thin sheet according to claim 1 , wherein a carbon footprint of manufacture of a foundry plate for manufacture of the thin sheet is less than 2 tons of CO 2 per foundry plate.
18 . A battery tray bottom made with a thin sheet according to claim 1 .
19 . A method for manufacturing the thin sheet according to claim 1 comprising the following successively:
a. Manufacture of a foundry plate optionally by vertical semi-continuous casting,
b. Homogenization at a temperature of at least 540° C. for 1.5 hours,
c. Hot rolling,
d. Cold rolling with an optional reduction rate of at least 60%,
e. Solution treatment at a temperature of at least 500° C., then quenching.
20 . The method for manufacturing the thin sheet according to claim 19 comprising the following successively:
a. Manufacture of the foundry plate optionally by vertical semi-continuous casting,
b. Homogenization at a temperature of at least 550° C. for at least 4 hours,
c. Hot rolling,
d. Cold rolling with an optional reduction rate of at least 60%,
e. Solution treatment at a temperature of at least 500° C., then quenching, and coiling at a temperature from 50° C. to 100° C.