Table 1
Chemical composition of typical aluminum alloys.
| Alloy | Zn | Mg | Cu | Fe | Cr | Si | Mn | Ti | Zr |
|---|---|---|---|---|---|---|---|---|---|
| 7075 | 5.1–6.1 | 2.1–2.9 | 1.2–2 | ≤0.5 | 0.18–0.28 | ≤0.4 | ≤0.3 | ≤0.2 | 0.08–0.25 |
| 7020 | 4–5 | 1–1.4 | ≤0.2 | ≤0.4 | 0.1–0.35 | ≤0.35 | 0.05–0.5 | ≤0.25 | 0.12 |
| 7xxx_1 | 7–8 | 1.2–1.8 | 1.3–2 | 0.08 | 0.04 | 0.06 | 0.04 | 0.06 | 0.08–0.15 |
Table 2
Mechanical properties of typical aluminum alloys.
| Alloy | Density (kg/m3) | R m (MPa) | R p0.2 (MPa) | A 50 (%) | Hardness (HV1) |
|---|---|---|---|---|---|
| 7075 T6 | 2,810 | 540–580 | 460–500 | 8–12 | 180–198 |
| 7020 T6 | 2,780 | 350–380 | 280–310 | 8–10 | 108–115 |
| 7xxx_1 | 2,800 | 517–525 | 486 | 11–16 | 127–155 |
Figure 1
Graphic diagram of the warm forming process (own drawing).
Figure 2
Schematic diagram of the warm forming process in the form of a temperature–time graph (own drawing).
Figure 3
True stress–strain curves of AA7075 at elevated temperatures [11].
Figure 4
(a) True stress–strain curves of AA7075 at 220°C and (b) strain rate sensitivity parameter (m) [11].
Figure 5
(a) True stress–strain curves and (b) true tensile/yield strength of AA7075 [13].
Figure 6
The true stress–strain curves of the AA7075-T6 alloy under (a) different temperatures with a strain rate of 0.1 s−1 and (b) different strain rates with a temperature of 300°C [15].
Figure 7
Influence of the forming temperature on the formability in the warm and hot forming of (a) EN AW7022-T6 and (b) EN AW7075-T6 [16].
Figure 8
(a) YS, (b) peak stress, (c) true uniform strain, and (d) true fracture strain of AW-7020-T6 [10].
Figure 9
Influence of forming temperature on strength AA7075 T6 taking into account the sheet thickness (own drawing).
Figure 10
Influence of forming temperature on strength AA7020 T6 taking into account the heating time (own drawing).
Figure 11
Geometry of shaping tools in tests (a) LDH and (b) LDR (own drawing).
Figure 12
Dependence of (a) LDH and (b) LDR of forming temperature (the dashed horizontal line indicates the alloy AA5182-O that has the best workability at ambient temperature) [11].
Figure 13
(a) Erichsen values of 7075-T6 as a function of test temperatures and (b) Vickers hardness of 7075 (PB – paint baking) [13].
Figure 14
LDR and LDD value at elevated temperature [10].
Figure 15
Visual inspection of the part sidewall isothermally formed at 204°C for (a) Fuchs, (b) PTFE Spray, (c) OKS, and (d) at 233°C utilizing the Fuchs lubricant [9].
Figure 16
Peak values during isothermal cup drawing at 170°C utilizing different lubricants [9].
Figure 17
Comparison of perimeter (a) and draw-in length and (b) of cups drawn under isothermal conditions utilizing different lubricants [9].
Figure 18
CAD model of car bracket [14].
Figure 19
FEM of a formed B-pillar (a) thickness deformation and (b) temperature distribution [18].
Figure 20
Mechanical properties of the drawpiece manufactured (a) conventionally and (b) by accelerated heating [18].
Figure 21
Model of the formed component (B-pillar) [15].
Figure 22
Mechanical properties of warm-stamped components [15].
Figure 23
U-profile (a) geometric dimension and (b) forming tools [9].
Figure 24
Force evolution as a function of the punch stroke for isothermal warm forming of the structural U-profile at 204°C utilizing different lubricants [9].
Figure 25
Visual inspection of the part sidewall isothermally formed at 204°C for (a) Fuchs, (b) PTFE Spray, (c) OKS, and (d) at 233°C utilizing the Fuchs lubricant [9].
Figure 26
Model of manufactured elements (a) U-shape profile and (b) the B-pillar’s foot [17].
Figure 27
The influence of the heating strategy on the strength of the U-profile (a) front, (b) flange, and (c) lateral [17].
Figure 28
Shape deviations measured in the cross-section of the U-shape (a) second strategy and (b) third strategy [17].
Figure 29
The influence of the heating strategy on the stress–strain curves of different areas of the B-pillar’s foot [17].
Figure 30
The influence of the sheet metal heating method on (a) hardness and (b) stress–strain curves, FH – conventional sheet heating, CH – contact heating, PB – paint baking [19].
Figure 31
Precipitation size distribution after (a) CH200 and (b) FH200 treatment [19].
Figure 32
TEM images of samples (a) CH200 + PB and (b) FH200 + PB [19].