Table 1
Mechanical properties of typical aluminum alloys for WT-F.
| Alloy | Density (kg/m3) | R m (MPa) | R p0.2 (MPa) | A 50 (%) | Hardness (HV1) |
|---|---|---|---|---|---|
| 7075 T6 | 2,810 | 540–570 | 460–500 | 8–12 | 180–198 |
| 7021 T6 | 2,900 | 400–490 | 350–420 | 8–11 | 127–155 |
| 7xxx_1 | 2,800 | 517–525 | 486 | 11–16 | 127–155 |
Table 2
Chemical composition of typical aluminum alloys for WT-F (%).
| Alloy | Zn | Mg | Cu | Fe | Cr | Si | Mn | Ti |
|---|---|---|---|---|---|---|---|---|
| 7075 | 5.1–6.1 | 2.1–2.9 | 1.2–2 | ≤0.5 | 0.18–0.28 | ≤0.4 | ≤0.3 | ≤0.2 |
| 7021 | 5–6 | 1.2–1.8 | ≤0.25 | ≤0.4 | ≤0.05 | ≤0.25 | ≤0.1 | ≤0.1 |
| 7xxx_1 | 7–8 | 1.2–1.8 | 1.3–2 | 0.08 | 0.04 | 0.06 | 0.04 | 0.06 |
Figure 1
Graphic diagram of the WT-F process (author’s own drawing).
Figure 2
Schematic diagram of the quench forming process in the form of a temperature-time graph (author’s own drawing).
Figure 3
The effect of solutioning temperature on the hardness of EN AW-7075: (a) Procedure and (b) results (author’s own drawings based on [14]).
Figure 4
Effect of solutioning time on material hardness: (a) Procedure and (b) results (author’s own drawings based on [14]).
Figure 5
Tensile tests of solution heat treated sheets [17].
Figure 6
Procedure diagram (author’s own drawing based on [18]).
Figure 7
Stress–strain curves for specimens obtained from the different simulated process routes [18].
Figure 8
(a) YS and UTS, (b) elongation at fracture, and (c) strain rate sensitivity of 7021 and 7075 at different temperatures/tempers and strain rates [19].
Figure 9
Hardness after SHT at different oven times: (a) Methodology and (b) results (author’s own drawings based on [17]).
Figure 10
Hardness after SHT and natural aging at different times: (a) Methodology and (b) results (author’s own drawings based on [17]).
Figure 11
Research methodology of PH and T4 treatment (author’s own drawing based on [23]).
Figure 12
Mechanical properties of alloys in different tempered states subjected to varied deformation levels: (a) T4-temper alloy and (b) PH alloy [23].
Figure 13
Mechanical properties of alloys in different tempered states after various deformation levels and paint-bake treatments: (a) T4-temper alloy and (b) PH alloy [23].
Figure 14
(a) Tool dimensions for the forming limit test, (b) specimens for different loading paths, (c) measured FLD for the T6 and (d) WT sheets, and (e) LDHs between the T6 and WT sheets [20].
Figure 15
Forming limit curves for AW 7075-WT and T6 [22].
Figure 16
The effect of aging temperature on the hardness of EN AW-7075: (a) Methodology and (b) results (author’s own drawing based on [14]).
Figure 17
The effect of aging time on the hardness of EN AW-7075: (a) Methodology, (b) results (author’s own drawing based on [14]).
Figure 18
Schematic diagram of thermoplastic treatment of EN AW-7075 (author’s own drawing based on [25]).
Figure 19
Effects of SHT & water quenching, PA, and PB on (a) stress vs strain curves and (b) mechanical properties of EN AW-7075 [25].
Figure 20
Effect of artificial aging duration on mechanical properties of EN AW-7075-W_SAA&PB: (a) YS and UTS, and (b) f and PSE [25].
Figure 21
Schematic diagram of thermoplastic treatment of 7075 and 7xxx_1 alloys (author’s own drawing based on [10]).
Figure 22
Hardness measurements for EN AW-7075 samples subject to a two-step heat treatment [10].
Figure 23
Measured stress–strain curves of EN AW-7075 [10].
Figure 24
Hardness measurements of aged 7xxx samples [10].
Figure 25
(a) Cross section of U-shape profiles and (b) lower part of the corresponding forming tool [19].
Figure 26
Photo of the finished U shapes after forming [19].
Figure 27
Pre- and post-forming microstructure for the hot forming and WT-F processes [19].
Figure 28
The effect of natural aging time on the hardness of the alloy depending on the processing [19].
Figure 29
Effect of natural aging and PB process on (a) YS and (b) elongation [19].
Figure 30
Strain distribution and mechanical property test diagram of cap beam component under T4/PH-X%-PB treatment conditions [23]. (x1, x2) physical and strain distribution diagram, (x3, x4) mechanical property test diagram.
Figure 31
(a) Dimensions of the tools and (b) comparison of springback profiles [20].
Figure 32
Springback parameters depending on the condition of the 7075 alloy [20].
Figure 33
Schematic diagram of thermoplastic treatment of 7075 (author’s own drawing based on [17]).
Figure 34
Final properties of stamped parts (author’s own drawing based on [17]).
Figure 35
(a) View of the lower part of the stamping tools and pillar strength test locations, (b) finished B-pillar, and (c) stress–strain curves of different parts of the B-pillar [12].
Figure 36
Influence of tools correction on the final shape of B-pillar: (a) Before correction and (b) after correction [12].
Figure 37
Effect of post-forming heat treatments on UTS and PSE of formed parts (SAA – shortened artificial aging) [25].
Figure 38
Sampling positions of uniaxial tensile specimens [25].
Figure 39
Mechanical properties of Al 7075 sheet and stamped beam: (a) Strength and (b) elongation (author’s own drawing based on [26]).
Figure 40
Specific dimension of tooling with a flat-headed punch [27].
Figure 41
Comparison of hole-expansion experimental result for EN AW-7075-T6 and EN AW-7075-W: (a) Punch force–displacement curves, (b) cup height, and (c) average expanded hole diameters in the RD of deformed specimens [27].
Figure 42
Thickness strain variation onset of fracture of EN AW-7075-T6 and EN AW-7075-W [27].