REINFORCING STRUCTURAL COMPONENTS

Abstract

Methods and tools for manufacturing reinforced structural components are described. The methods comprise providing a structural component having a steel substrate and a metal coating layer. The method further comprises selecting a reinforcement zone of the structural component, guiding a first laser beam to ablate at least a part of the coating layer of the reinforcement zone, locally depositing a reinforcement material on the ablated reinforcement zone to create a local reinforcement on a first side of the structural component, wherein locally depositing a material on the reinforcement zone comprises supplying a reinforcement material to the ablated reinforcement zone, and substantially simultaneously applying laser heating using a second laser beam to melt the reinforcement material and part of the steel substrate of the ablated reinforcement zone to mix the melted reinforcement material with the melted part of the steel substrate. The disclosure further relates to reinforced components obtained using such methods.

Claims

1. Method for manufacturing reinforced steel structural components, the method comprising: providing a previously formed steel structural component having a steel substrate and a metal coating layer, selecting a reinforcement zone of the previously formed steel structural component, selecting a first direction in the reinforcement zone; guiding a first laser beam along the first direction to ablate a part of the coating layer of the reinforcement zone; locally depositing a material on the ablated reinforcement zone to create a local reinforcement on a first side of the structural component, wherein locally depositing a material on the reinforcement zone comprises supplying a reinforcement material to the ablated reinforcement zone, and substantially simultaneously applying laser heating along the first direction using a second laser beam in unison with the first laser beam to melt the reinforcement material and part of the steel substrate of the ablated reinforcement zone to mix the melted reinforcement material with the melted part of the steel substrate.

2. Method according to claim 1, wherein the first laser beam comprises a single spot laser beam.

3. Method according to claim 1, wherein the first laser beam and/or the second laser beam comprises a twin spot laser beam, wherein the two spots are arranged substantially perpendicularly to the first direction.

4. Method according to claim 3, wherein the two spots are distributed evenly in the reinforcement zone.

5. Method according to claim 1, wherein the reinforcement material comprises a metal powder provided in a powder gas flow.

6. Method according to claim 1, wherein the reinforcement material comprises a solid metal provided as a metal wire.

7. Method according to claim 1, further comprising drawing specific geometric shapes on the first side of the structural component with the reinforcement material and the laser heating.

8. Method according to claim 1, further comprising providing cooling to areas on a second side of the structural component that is opposite to the first side.

9. Method according to claim 1, wherein the metal coating layer is a layer of aluminum or of an aluminum alloy or of zinc or of a zinc alloy.

10. Method according to claim 1, wherein the steel substrate is made from boron steel.

11. Method according to claim 1, wherein the previously formed structural component is obtained by hot forming die quenching.

12. Tool for reinforcing previously formed steel structural components, comprising: an imaging device to select a reinforcement zone of a previously formed structural component having a metal coating, a laser head configuration, comprising: a laser beam source to generate a first laser beam and a second laser beam; the laser head configuration configured to direct the spot of the second laser beam at a distance of between 2mm and 50mm from the spot of the first laser beam; a reinforcement material depositor; a controller, coupled to the imaging device, the laser head configuration and the reinforcement material depositor, configured to select a first direction based on data received from the imaging device; guide the first laser beam along the first direction to ablate a part of the metal coating of the reinforcement zone; instruct the reinforcement material depositor to locally deposit a metal filler material on the ablated reinforcement zone; guide the second laser beam along the first direction in unison with the first laser beam to apply laser heating to melt the metal filler material and create the reinforcement.

13. Tool according to claim 12, wherein the laser beam source comprises a first laser source to generate a first laser beam and a second laser source to generate a second laser beam, wherein the first and second laser sources are comprised in a single laser head.

14. Tool according to claim 12, wherein the laser beam source comprises a first laser source to generate a first laser beam and a second laser source to generate a second laser beam, wherein the first laser source is comprised in a first laser head and the second laser source in a second laser head, the first and second laser heads arranged to be moveable in unison.

15. A product as obtainable by a method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Non-limiting examples of the present disclosure will be described in the following with reference to the appended drawings, in which:

[0044] FIG. 1 shows an example of manufacturing a reinforced steel structural component.

[0045] FIG. 2 shows an example reinforced steel structural component;

[0046] FIG. 3 is a top view of a reinforcement operation according to an example;

[0047] FIG. 4 shows a tool for reinforcing a reinforcement zone 12 of a previously formed steel structural component according to an example;

[0048] FIGS. 5a-5d show examples of different specific reinforcement geometries that may be obtained by a method substantially as hereinbefore described;

[0049] FIGS. 6 and 7 each shows an example of a reinforced component manufactured by any method substantially as hereinbefore described;

[0050] FIG. 8 is a flow diagram of a method of manufacturing reinforced steel structural components according to an example.

DETAILED DESCRIPTION OF EXAMPLES

[0051] FIG. 1 shows an example of manufacturing a reinforced steel structural component. A previously formed steel structural component 10 may comprise a steel substrate 15 and a coating layer 15 (e.g. of aluminum or of an aluminum alloy or of zinc or of a zinc alloy). A laser head 25 may comprise a first laser source 27 and a second laser source 29. The first laser source 27 may generate a first laser beam 30 that may be used to ablate a portion of the coating layer 20. The first laser beam 30 may be guided by the first laser source 27 that may be an individual laser head or may form part of a laser head that may be shared between the first laser source 27 and the second laser source 29. The first laser source 27 may be a pulsed laser, e.g. a Q-switched laser having a nominal energy of 450 W delivering a 70 nsec pulse with a pulse energy of 42 mJ.

[0052] The laser head 25 may be relatively displaced in a first direction 5 with respect to the previously formed steel structural component 10 so as the first laser beam 30 to be applied to the coating layer 20. The first direction 5 may be a direction along a path that may require reinforcement. Therefore, ablation may take place only in a selected reinforcement zone of the previously formed steel structural component 10 where reinforcement may be required. A material depositor 40 may then be used to locally deposit a material 45 on the ablated reinforcement zone to create a local reinforcement on the structural component.

[0053] The material depositor 40 may provide reinforcing material 45 e.g. in the form of a solid wire or in the form of powder. The reinforcing material may be heated and melted in the ablated reinforcement zone with the use of the second laser beam 35 generated by the second laser source 29. The material depositor 40 may be moveable in unison with the laser head 25.

[0054] The material depositor 40 may be part of a single reinforcement applier 50 that may include the material depositor 40 and the laser head 25 or it may be separate but synchronised with the laser head configuration 25 so that they are moveable in tandem. The material depositor 40 may be a gas powder nozzle providing a gas powder flow. The gas powder nozzle may be coaxially arranged with the second laser source 29 so that the gas powder flow and the laser beam may be substantially perpendicular to a surface of the component on which the reinforcement is to be formed. The gas powder flow may thus be fed to the reinforcement zone while the second laser beam is being applied. In alternative examples, the gas powder flow may be fed at an angle with respect to the component. In some of these examples, the gas powder flow may also be fed at an angle with respect to the laser beam or it may be coaxially arranged with respect to the laser beam as in the previous example. Alternatively, a solid wire may be used to provide the reinforcement material.

[0055] As the reinforcement operation progresses along the first direction the reinforcement material that has been heated and melted in the reinforcement zone may begin to cool down and solidify on the ablated reinforcement zone. The solidified reinforcement material may thus cover all the area that was ablated thus minimising corrosion zones in unprotected border areas.

[0056] The power of the first laser source should be enough to melt at least the coating layer of the previously formed component having a typical thickness i.e. in the range of 0.7-5 mm.

[0057] The second laser source may have a power sufficient to melt at least the reinforcement material (powder or wire) throughout the entire zone on which the reinforcement is to be formed.

[0058] In some examples, melting may comprise melting using a laser having a power of between 2 kW and 16 kW, optionally between 2 and 10 kW.

[0059] By increasing the power of the lasers the overall velocity of the process may be increased.

[0060] Optionally, a Nd-YAG (Neodymium-doped yttrium aluminum garnet) laser may be used. These lasers are commercially available, and constitute a proven technology. This type of laser may also have sufficient power to melt an outer surface (coating layer) of a formed component and allows varying the width of the focal point of the laser and thus of the reinforcement zone. Reducing the size of the spot increases the energy density, whereas increasing the size of the spot enables speeding up the ablation process. The spot may be very effectively controlled and various types of ablation are possible with this type of laser. This type of laser may also have sufficient power to melt the reinforcement material on the ablated zone. However, the power required for ablating the coating layer may be different from the power required for melting the reinforcement material. Thus, two such lasers may be necessary or a dual-source laser with varying power per spot.

[0061] In alternative examples, a CO.sub.2 laser with sufficient power or a diode laser may be used.

[0062] FIG. 2A shows an example of a reinforced steel structural component manufactured according to the process discussed with reference to FIG. 1. The reinforced component 200 may comprise a steel substrate 15, a coating layer 20 and reinforcement 60. The reinforcement 60 may be substantially deposited in an ablated area of the coating layer 20, melted and mixed with a portion of the steel substrate 15. As shown in FIG. 2, the reinforcement may adhere and dilute directly with the steel substrate in the ablated coating layer zone and partially to the side of the coating layer 20 leaving substantially no ablated steel substrate area uncovered. The benefits of a component or product reinforced using the above process shall be explained when compared with two alternative reinforcement processes discuss hereinafter with reference to FIG. 2B and FIG. 2C.

[0063] FIG. 2B shows a reinforced steel structural component where reinforcement material was added without prior ablation of the coating layer. The steel component 10 may have a steel substrate 15 and a coating layer 20 in a similar manner as the component discussed with reference to FIG. 1. A reinforcement material 60 in the form of powder or wire may be deposited with laser heating on the steel component 10 and effectively on the coating layer. Although the reinforcement as provided with this process may be sufficient in circumstances, as it is shown in FIG. 2B, at least part (indicated with the letter u) of the reinforcement material 60 may not be diluted and mixed with the steel substrate 15 when heated but remains or gets diluted partly within the coating layer. This may result in non-homogeneous and therefore poorer performance of the reinforced steel structural component 10 at the affected areas when compared with the reinforced steel structural component discussed with reference to FIG. 2A.

[0064] FIG. 2C shows a reinforced steel structural component where a part of the coating layer has been first laser ablated and where subsequently a stainless steel component was attached in the ablated area. As the size of the steel component may not correspond 100% with the size of the ablated area, the border areas (indicated with the letter b) of the ablated areas of the steel substrate may be prone to corrosion as the steel substrate is not stainless, i.e. the coating layer 20 was providing protection from oxidisation. Such a situation may be avoided with the product discussed with ref. to FIG. 2A, as the deposited reinforcement material when melted may flow and cover all the ablated area and leave no border areas uncovered and prone to oxidisation or corrosion.

[0065] FIG. 3A is a top view of a reinforcement operation according to an example. A reinforcement zone 12 is selected on a previously formed steel structural component 10 having a coating layer. A first laser beam 30 comprises a twin-spot laser beam may be moveable along the first direction 5. The twin-spot laser beam may ablate the reinforcement zone 12 along the operation path. A second laser beam 35 may then heat and fuse a reinforcing material (not shown) deposited in the ablated zone. Depending on the reinforcement zone, the laser beam may provide a single oval or rectangular spot or a twin-spot. The size of the spot may be such as to cover at least the area of the reinforcement zone where dilution of the reinforcement material is desired. FIG. 3B is a top view of an example reinforcement operation using a first laser beam 30 with a single rectangular spot for ablation. As shown in FIG. 3A and 3B the size of the spot of the first laser beam may be substantially smaller than the size of the small of the second laser beam. Accordingly, the power of the first laser source may be substantially lower than the power of the second laser source. The power of the first laser source may be around 450 W while the power of the second laser source may be between 2 kW and 16 kW, optionally between 2 kW and 10 kW.

[0066] FIG. 4 shows a tool for reinforcing a reinforcement zone 12 of a previously formed steel structural component according to an example. A first optical fiber may provide a first optical signal to beam shaper 24 and a second optical fiber may provide a second optical signal to beam shaper 24. The beam shaper 24 may then provide the optical signals to the laser head configuration 25. The laser head configuration 25 may generate the first laser beam 30 to be used for ablation of the coating layer of the reinforcement zone 12. The laser head configuration 25 may also generate the second laser beam 35 to be used for heating and melting the reinforcement material (not shown) on the ablated reinforcement zone. The tool may be moveable along the first direction 5. Thus, a reinforced steel structural component may be generated along a path of a selected reinforcement zone. An imaging device 70, e.g. a camera, may be used to select the reinforcement zone. A controller 80 may be coupled to the imaging device and to the laser head configuration 25 to receive the information from the imaging device and guide the laser beams on the selected reinforcement zone.

[0067] FIGS. 5A-5D show different examples of specific reinforcement geometries that may be obtained with methods substantially as hereinbefore described. As mentioned above, using a laser to melt a reinforcement material (powder or solid wire) may allow the formation of almost any desired geometry having e.g. different curvature, different size (length, width and height) or even crossing lines defining a grid. These methods are quite versatile. No extra material in a zone that does not need reinforcement is provided, and the final weight of the component may thus be optimized.

[0068] For example, FIGS. 5A and 5C show different discrete known shapes such as rectangles, squares, annular rings, half a ring and a cross among other possibilities. FIG. 5B shows curved lines defining each a substantially sinusoidal form and FIG. 5D shows straight lines crossing each other to define a grid.

[0069] It has been found that local reinforcements having a minimum thickness of 0.2 mm lead to good results while optimizing the weight of the final reinforced component. The minimum thickness may be obtained with e.g. only one material (e.g. powder or wire) deposition. Furthermore, each laser exposure and material deposition may involve a maximum thickness of approximate 1 mm. In some examples, the local reinforcement may have a thickness between approximately 0.2 mm and approximately 6 mm. This may be achieved with repetitive depositions of material or by slowing down the process.

[0070] And in more examples, the local reinforcement may have a thickness between approximately 0.2 mm and approximately 2 mm. In all these examples, the width of the local reinforcement with each material deposition and laser exposure may generally be between approximately 1 mm to approximately 10 mm.

[0071] FIGS. 6 and 7 show different reinforced components obtained by any method substantially as herein described. In the example of FIG. 6 a B pillar 8 is schematically illustrated. In the example of FIG. 7 a bar 9 e.g. a cross/side member is schematically illustrated. Both components 8 and 9 may be formed e.g. by HFDQ process. In alternative examples, other ways of forming the component may also be foreseen such as cold forming, hydroforming or roll forming. Reinforcements 64 and 65 may be added by ablating the coating layer and depositing a reinforcement material while applying the second laser beam to melt the reinforcement material. Reinforcements 64 and 65 are designed e.g. to direct tensions and increase stiffness (rigidity) of the component. E.g. reinforcements 64 may be applied in order to improve strength in case of an impact in areas such as corners, end portions and reinforcements 65 may be applied in order to add strength to the component due to e.g. a hole made during manufacture so that the whole strength of the component is not affected by the presence of the hole. In general in a component, reinforcements may be required in those areas that need to withstand most loads, e.g. in a B pillar these areas are the corners.

[0072] FIG. 8 is a flow diagram of a method of manufacturing reinforced steel structural components according to an example. In a first block 81, a previously formed steel structural component is provided. The previously formed steel structural component may have a coating layer of e.g. aluminum or of an aluminum alloy. In block 82, a reinforcement zone of the previously formed steel structural component may be selected. In block 83, a first direction in the reinforcement zone may be selected. Then, in block 84, a first laser beam may be guided along the first direction to ablate a part of the coating layer of the reinforcement zone. In block 85, a material may be locally deposited on the ablated reinforcement zone to create a local reinforcement on a first side of the structural component. In block 86, laser heating may be substantially simultaneously applied along the first direction using a second laser beam to melt the reinforcement (metal filler) material and create the reinforcement. The first and the second laser beam may be moved in unison. In block 87, the reinforced component may be cooled or allowed to cool to so that the reinforcement material may adhere to the ablated steel substrate.

[0073] Although only a number of examples have been disclosed herein, other alternatives, modifications, uses and/or equivalents thereof are possible. Furthermore, all possible combinations of the described examples are also covered. Thus, the scope of the present disclosure should not be limited by particular examples, but should be determined only by a fair reading of the claims that follow.