Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
76 words
A heat treated and aged Al-base alloy of high strength and high ductility characterised in that it consists essentially of (in % by weight): ______________________________________
Li 1.7 to 2.9
Cu 1.5 to 3.4
##STR4##
Mg 1.2 to 2.7
Fe ≦ 0.20
Si ≦ 0.12
Cr 0 to 0.3
Mn 0 to 1.0
Zr 0 to 0.2
Ti 0 to 0.1
Be 0 to 0.02
other elements (impurities)
each ≦ 0.05
Total ≦ 0.15
balance: aluminium
______________________________________
Claim 2
Dependent Claim
76 words
A heat treated and aged Al-base alloy of high strength and high ductility characterised in that it consists essentially of (in % by weight): ______________________________________
Li 1.7 to 2.9
Cu 1.5 to 3.4
##STR4##
Mg 1.2 to 2.7
Fe ≦ 0.20
Si ≦ 0.12
Cr 0 to 0.3
Mn 0 to 1.0
Zr 0 to 0.2
Ti 0 to 0.1
Be 0 to 0.02
other elements (impurities)
each ≦ 0.05
Total ≦ 0.15
balance: aluminium
______________________________________
Claim 3
Dependent Claim
17 words
An alloy according to claim 1 characterised in that it contains from 1.7 to 2.5% of Li.
Claim 4
Dependent Claim
20 words
An alloy according to claim 1 or claim 2 characterised in that it contains from 1.7 to 3% of Cu.
Claim 5
Dependent Claim
17 words
An alloy according to claim 3, characterised in that it contains from 2 to 2.7% of Cu.
Claim 6
Dependent Claim
17 words
An alloy according to claim 1 characterised in that it contains from 1.2 to 2.2% of Mg.
Claim 7
Dependent Claim
18 words
An alloy according to claim 1 characterised in that it contains at most 0.10% Fe and 0.06% Si.
Claim 8
Dependent Claim
13 words
An alloy according to claim 1 characterised in that: %Li(%Cu+2)+%Mg=K ps with 8.5≦K≦11.5.
Claim 9
Dependent Claim
10 words
An alloy according to claim 7 characterised in that 9≦K≦11.
Claim 10
Dependent Claim
49 words
A process for the heat treatment of the alloy of claim 1 comprising a homogenization step, a solution treatment, a quenching step and a tempering step characterised in that the alloy is subjected to homogenization and solution treatment at a temperature (in °C.) of the order of θ=535-5 (%Mg).
Claim 11
Dependent Claim
43 words
A process according to claim 9 characterised in that the duration of the homogenization step and the solution treatment is sufficiently long that after the quenching operation the intermetallic phases of type Al-Cu-(Li,Mg) are of a size between 0 and 5 μm, inclusive.
Claim 12
Dependent Claim
29 words
A process according to claim 9 or claim 10 characterised in that the homogenization operation is carried out in the temperature range defined by θ+10 (°C.) and θ-20 (°C.).
Claim 13
Dependent Claim
29 words
A process according to claim 9 or claim 10 characterised in that the solution treatment is carried out in the temperature range defined by θ+10 (°C.) and θ-10 (°C.).
Claim 14
Dependent Claim
32 words
A process according to claim 9 or 10 characterised in that the tempering operation is carried out at from 170° to 220° C. for a period ranging from 8 to 48 hours.
Claim 15
Dependent Claim
21 words
A process according to claim 13 characterised in that the tempering operation is carried out at from 180° to 200° C.
Claim 16
Dependent Claim
33 words
A process according to claim 9 or 10 characterised in that a degree of plastic deformation of from 1 to 5% is applied to the treated product between the quenching and tempering operations.
Claim 17
Dependent Claim
17 words
A process according to claim 15, wherein said degree of plastic deformation is from 2 to 4%.