Hot stamping method for forming aluminum

Abstract

A hot stamping aluminum forming method comprises: a first stage in which an aluminum panel is subjected to solution treatment, forming treatment and quenching treatment in a stamp die, the first stage being carried out over a first period and having a second period of about 2 to 6 minutes in which the aluminum panel is subjected to a temperature of about 540 to 550°C, the first stage also having an in-die quenching treatment of the aluminum panel after the second period; and a second stage in which the aluminum panel is subjected to a pre-aging treatment in a second stage after the first stage, the second stage having a third period of about 30 to 60 minutes in which the aluminum panel is subjected to a temperature of about 200 to 210°C.

Description

Technical Field

[0001] This document relates to a hot stamping type aluminum forming method.

Background Art

[0002] Modern vehicle design is influenced by the increasing emphasis on vehicle collision safety that characterizes today's automotive manufacturing industry. For the protection against side collisions of vehicles, several different energy absorption mechanisms have been used. With the emergence of electric vehicles, the protection of the battery pack placed at the bottom of the vehicle body has also become an important goal. Some previous approaches in vehicle side collision protection have been based on extruded materials such as aluminum. However, the extrusion process provides rails with a certain profile, which cannot adjust the collision protection or be adapted to a specific design of the vehicle body.

Summary of the Invention

[0003] In one aspect, a hot stamping type aluminum forming method includes the steps of subjecting an aluminum panel to solution treatment, forming treatment, and quenching treatment in a stamp die during a first stage, the first stage being carried out through a first period and having a second period of about 2 - 6 minutes in which the aluminum panel is subjected to a temperature of about 540 - 550 °C, and the first stage also having an in-die quenching treatment of the aluminum panel after the second period; and subjecting the aluminum panel to a pre-aging treatment during a second stage after the first stage, the second stage having a third period of about 30 - 60 minutes in which the aluminum panel is subjected to a temperature of about 200 - 210 °C.

[0004] The implementation may include any or all of the following features: The first and second stages form stamped panels for an energy-absorbing side structure for a vehicle, the stamped panels having a series of ridges, each extending substantially perpendicular to the longitudinal axis of the stamped panel. The aluminum panel contains approximately 0.40–1.00% Mn, approximately 0.0–0.50% Fe, approximately 0.60–1.20% Mg, approximately 0.70–1.30% Si, approximately 0.0–0.10% Cu, approximately 0.0–0.20% Zn, approximately 0.0–0.10% Ti, approximately 0.0–0.25% Cr, approximately 0.0–0.15% residue, and the remainder aluminum. The first period is approximately 12 minutes. The second period is approximately 3–5 minutes. The second period is approximately 4 minutes. The die quenching process is performed in a fourth period, which is shorter than the second period. The first stage further includes a heating stage in which the aluminum panel is heated to a temperature of approximately 540-550°C, and the die quenching process is performed in a fourth period, which is shorter than the heating stage. The hot stamping aluminum forming method further includes a step in which the aluminum panel undergoes natural aging during the third stage, immediately following the second stage, and the natural aging process is performed with the aluminum panel removed from the die. The hot stamping aluminum forming method further includes a step of providing the aluminum panel for a holding period between the second period and the die quenching process. The second stage lasts for approximately 70-80 minutes. The second stage lasts for approximately 75 minutes. The hot stamping aluminum forming method further includes a step of painting and firing the aluminum panel after the second stage. The hot stamping aluminum forming method further includes a step of assembling the aluminum panel with another aluminum panel after the second stage and before painting and firing. The third period is approximately 40-50 minutes. The third period is approximately 45 minutes long. [Brief explanation of the drawing]

[0005] [Figure 1] An example of a hot stamping method for forming aluminum is shown.

[0006] [Figure 2] Figure 1 shows an example of a press machine that can be used in the hot stamping aluminum forming method.

[0007] [Figure 3] An example of a vehicle energy-absorbing side structure, including a stamped panel, is shown.

[0008] [Figure 4] Figure 3 shows an example of one of the stamped panels of the energy-absorbing side structure.

[0009] Similar reference numerals in various drawings indicate the same elements. [Modes for carrying out the invention]

[0010] This document describes examples of systems and technologies that provide an improved hot-stamping aluminum forming method. In some implementations, the hot-stamping aluminum forming method can be used to manufacture energy-absorbing side structures for vehicles.

[0011] The examples described herein refer to vehicles. A vehicle is a machine that transports passengers, cargo, or both. A vehicle may have one or more motors that use at least one type of fuel or other energy source (e.g., electricity). Examples of vehicles include, but are not limited to, cars, trucks, and buses. The number of wheels may vary depending on the type of vehicle, one or more (e.g., all) of the wheels may be used for propulsion, or the vehicle may not have its own power source (e.g., if a trailer is attached to another vehicle). A vehicle may include a passenger compartment that accommodates one or more people.

[0012] The examples described herein refer to the top, bottom, front, side, or back. These and similar expressions identify things or aspects relatively, based on an explicit or arbitrary concept of viewpoint. That is, these terms are for illustrative purposes only and are used for explanatory purposes.

[0013] Figure 1 shows an example of a hot-stamping aluminum forming method 100. Process 100 can be used in conjunction with one or more other examples described elsewhere in this specification. Process 100 is illustrated here with reference to an example in which time is shown on the horizontal axis and the temperature of the aluminum panel is shown on the vertical axis. Process 100 can be carried out for any of several different types of aluminum panels, including, but not limited to, those described in the examples further shown below.

[0014] Process 100 can begin with the aluminum panel at temper F, which is the temperature at which it is stamped. In stage 102, the aluminum panel can be subjected to solution treatment, forming, and quenching. Stage 102 can be performed while the aluminum panel is in the die for stamping, partly before stamping and partly during stamping. In short, solution treatment can prepare the aluminum panel for forming (e.g., by heating the panel before it enters the die), and the panel can be formed accordingly and quenched to a lower temperature. Stage 102 may include a period 102A in which the aluminum panel is heated. The heat treatment can begin at a lower temperature, such as the temperature at which it is stamped. Period 102A can have any of several lengths. For example, this is performed by heating the aluminum panel in an oven. Stage 102 may include a period 102B in which the aluminum panel is maintained at a substantially constant temperature. In some implementations, the temperature in period 102B can be about 540-550°C, for example, about 545°C. Period 102B can occur in the oven and can have any of several lengths. In some implementations, period 102B can be approximately 2 to 6 minutes. For example, period 102B can be approximately 3 to 5 minutes, for example, approximately 4 minutes. Stage 102 can include period 102C, which represents a holding period. In some implementations, the blank awaits transfer to the die during period 102C. For example, the blank may be held on a rack and its temperature may decrease somewhat. Stage 102 can include period 102D, in which the aluminum panel is formed in the die and subjected to die quenching. Die quenching can serve to suppress the growth of precipitates in the aluminum panel so that it does not become brittle during stamping. Die quenching can include bringing the aluminum panel to a temperature lower than that of periods 102B-102C. For example, the aluminum panel can be brought to substantially the same temperature as at the start of period 102A. Period 102D can have any of several lengths.For example, period 102D can be shorter than period 102A. Alternatively, period 102D can be shorter than period 102B. Stage 102 can have any of several lengths. For example, stage 102 can last approximately 12 minutes.

[0015] In Stage 104, the aluminum panel may be subjected to a preliminary aging treatment. Stage 104 can be carried out while the aluminum panel is outside the die. Preliminary aging (sometimes characterized as artificial aging) can gradually impart strength to the material of the aluminum panel and play a role in balancing strength and ductility. Stage 104 may include a period 104A in which the aluminum panel is transferred to the final aging oven. For example, this can be carried out at a non-high temperature (e.g., room temperature). Period 104A can have any of several lengths. In some implementations, period 104A can last for less than about 10 minutes. For example, Stage 104 may include a period 104B in which the temperature of the aluminum panel is rising. Period 104A may occur immediately before period 104B. Period 104B can have any of several lengths. Stage 104 may include a period 104C in which the aluminum panel is maintained at a substantially constant temperature. In some implementations, the temperature during period 104B can be approximately 200-210°C, for example, approximately 205°C. Period 104C can have any of several lengths. For example, period 104C can last for approximately 30-60 minutes, for example, approximately 40-50 minutes, for example, 45 minutes. Stage 104 may include period 104D, during which the temperature of the aluminum panel is decreasing. Period 104D can have any of several lengths. In some implementations, periods 104B, 104C, and 104D can last for approximately 70-80 minutes, for example, approximately 75 minutes. Stage 104 may include period 104E, during which the aluminum panel is subjected to natural aging. Period 104E can occur immediately after period 104D. During period 104E, the temperature should be stable. Period 104E can have any of several lengths. Stage 104 can have any of several lengths.

[0016] Stage 106 allows the aluminum panel to be painted and fired. This can serve to provide the aluminum panel (or possibly the panel assembly) with one or more properties, such as, to name just a few, surface texture, oxidation protection, surface coloring, anti-slip properties, abrasion protection, and / or electrical insulation. Stage 106 may include a period 106A in which the aluminum panel is brought to a temperature of about 160–180°C, for example, about 171°C, and maintained at that temperature for about 15–30 minutes, for example, about 20 minutes. Stage 106 may include a period 106B in which the aluminum panel is brought to a temperature of about 140–160°C, for example, about 149°C, and maintained at that temperature for about 5–15 minutes, for example, about 10 minutes. Stage 106 may include a period 106C in which the aluminum panel is brought to a temperature of about 55–75°C, for example, about 65°C, and maintained at that temperature for about 3–9 minutes, for example, about 6 minutes. Stage 106 may include a period 106D in which the aluminum panel is brought to a temperature of approximately 130-150°C, for example, approximately 140°C, and maintained at that temperature for approximately 20-30 minutes, for example, approximately 25 minutes.

[0017] Two or more components, including at least one aluminum panel manufactured according to process 100, can be assembled in assembly operation 108. In some implementations, two or more aluminum panels can be assembled. For example, two stamped panels can be assembled into an energy-absorbing side structure for a vehicle. At least one of such panels may have a series of ridges, each extending substantially perpendicular to the longitudinal axis of the stamped panel.

[0018] Process 100 can begin with selecting an aluminum panel from a suitable stock. Several different materials can be used, including but not limited to aluminum alloys. The selection of material and / or details of the hot stamping process can affect material properties such as strength, elongation, and / or ductility. In some implementations, stamped panels can be made using 6xxx aluminum alloys. For example, an aluminum alloy may contain approximately 0.40–1.00% manganese (Mn), approximately 0.0–0.50% iron (Fe), approximately 0.60–1.20% magnesium (Mg), approximately 0.70–1.30% silicon (Si), approximately 0.0–0.10% copper (Cu), approximately 0.0–0.20% zinc (Zn), approximately 0.0–0.10% titanium (Ti), approximately 0.0–0.25% chromium (Cr), approximately 0.0–0.15% residue, and the remainder being aluminum.

[0019] Figure 2 shows an example of a press 200 that can be used in the hot stamping aluminum forming method of Figure 1. The press 200 can be used in conjunction with one or more other examples described elsewhere in this specification. The press 200 comprises an upper die shoe 202 and a lower die shoe 204. The press 200 here comprises a die 206 attached to the upper die shoe 202. The die 206 defines at least one draw cavity 208 into which the aluminum panel 210 will be drawn during stamping using a punch 212 attached to the lower die shoe 204. During stamping, at least one binder 214 can be applied to the aluminum panel 210.

[0020] Figure 3 shows an example of an energy-absorbing side structure 300 for a vehicle, including stamped panels. Figure 4 shows an example of one of the stamped panels of the energy-absorbing side structure 300 of Figure 3. The energy-absorbing side structure 300 can be used in conjunction with one or more other examples described elsewhere in this specification. The energy-absorbing side structure 300 includes stamped panels 302 and stamped panels 304. Either or both of the stamped panels 302 or 304 can be formed using process 100 of Figure 1. The stamped panel 304 is assembled with the stamped panel 302 to form a sealed space. The stamped panel 302 may have one or more raised portions 306 (e.g., a series of raised portions 306) formed by stamping. Each raised portion 306 extends substantially perpendicular to the longitudinal axis of the stamped panel 302. The stamped panel 304 may also, or instead, have one or more raised portions. For example, such a raised portion may be different from or substantially the same as the raised portion 306.

[0021] The terms “substantially” and “about” as used throughout this specification are used to describe and account for small variations, such as those resulting from processing variability. For example, they may mean less than or equal to ±5%, for example less than or equal to ±2%, for example less than or equal to ±1%, for example less than or equal to ±0.5%, for example less than or equal to ±0.2%, for example less than or equal to ±0.1%, for example less than or equal to ±0.05%. Also, as used herein, indefinite articles such as “a” or “an” mean “at least one.”

[0022] It should be understood that all combinations of the above concepts and additional concepts discussed in more detail below are contemplated as being part of the subject matter of the invention disclosed herein, provided that such concepts are not mutually inconsistent. In particular, all combinations of the claimed subject matter that appear at the end of this disclosure are contemplated as being part of the subject matter of the invention disclosed herein.

[0023] A plurality of implementations have been described. Nevertheless, it will be understood that various modifications can be made without departing from the spirit and scope of this specification.

[0024] In addition, the logical flows shown in the figures do not require the particular order shown, or sequential order, to achieve desirable results. In addition, other processes may be provided, or processes may be eliminated from the flows described, other components may be added to the systems described, or other components may be removed from the systems described. Accordingly, other implementations fall within the scope of the following claims.

[0025] Certain features of the described implementations have been shown as described herein, but now many modifications, substitutions, changes, and equivalents will occur to those skilled in the art. Accordingly, it should be understood that the appended claims are intended to cover all such modifications and changes that fall within the scope of these implementations. They are presented by way of example only and not limitation, and it should be understood that various changes can be made in form and detail. Except for mutually exclusive combinations, any part of the apparatus and / or method described herein can be combined in any combination. The implementations described herein can include various combinations and / or sub-combinations of the functions, components, and / or features of the different implementations described.

Claims

1. The first stage involves subjecting an aluminum panel to solution treatment, molding treatment and quenching treatment in a stamp die, the first stage being carried out over a first period and having a second period of about 2 to 6 minutes in which the aluminum panel is subjected to a temperature of about 540 to 550°C, and the first stage also includes quenching the aluminum panel in the die after the second period; and The second stage, following the first stage, involves subjecting the aluminum panel to a preliminary aging treatment, the second stage having a third period of approximately 30 to 60 minutes in which the aluminum panel is subjected to a temperature of approximately 200 to 210°C. A hot stamping aluminum forming method comprising the following features.

2. The hot-stamping aluminum forming method according to claim 1, wherein the first stage and the second stage form a stamped panel for an energy-absorbing side structure for a vehicle, the stamped panel having a series of ridges each extending substantially perpendicular to the longitudinal axis of the stamped panel.

3. The aforementioned aluminum panel is Approximately 0.40-1.00% Mn, Approximately 0.0-0.50% Fe, Approximately 0.60-1.20% Mg, Approximately 0.70-1.30% Si, Approximately 0.0-0.10% Cu, Approximately 0.0-0.20% Zn, Approximately 0.0-0.10% Ti, Approximately 0.0-0.25% Cr, Approximately 0.0-0.15% residue, and Remaining aluminum A hot stamping aluminum molding method according to claim 1 or 2, including the above.

4. The hot stamping aluminum molding method according to claim 1 or 2, wherein the first period is approximately 12 minutes.

5. The hot stamping aluminum molding method according to claim 1 or 2, wherein the second period is approximately 3 to 5 minutes.

6. The hot stamping aluminum molding method according to claim 5, wherein the second period is approximately 4 minutes.

7. The hot stamping aluminum forming method according to claim 1 or 2, wherein the die quenching treatment is performed in a fourth period shorter than the second period.

8. The hot stamping aluminum forming method according to claim 1 or 2, wherein the first stage further comprises a heating stage when the aluminum panel is heated to a temperature of about 540 to 550°C, and the die quenching treatment is performed for a fourth period shorter than the heating stage.

9. The hot stamping aluminum molding method according to claim 1 or 2, further comprising a step of performing a natural aging treatment of the aluminum panel during a third stage immediately following the second stage, wherein the natural aging treatment is performed with the aluminum panel removed from the die.

10. The hot stamping aluminum forming method according to claim 1 or 2, further comprising the step of providing the aluminum panel during the second period and the holding period between the die quenching treatment.

11. The hot stamping aluminum molding method according to claim 1 or 2, wherein the second stage continues for approximately 70 to 80 minutes.

12. The hot stamping aluminum molding method according to claim 11, wherein the second stage continues for approximately 75 minutes.

13. The hot stamping aluminum molding method according to claim 1 or 2, further comprising the step of painting and firing the aluminum panel after the second stage.

14. The hot stamping aluminum molding method according to claim 13, further comprising the step of assembling the aluminum panel with another aluminum panel after the second stage and before the painting and firing.

15. The hot stamping aluminum molding method according to claim 1 or 2, wherein the third period is approximately 40 to 50 minutes.

16. The hot stamping aluminum molding method according to claim 15, wherein the third period is approximately 45 minutes.

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