Combined process of hot and cold forging with different forging directions

Abstract

The invention relates to a combination of methods for producing a component by closed-die hot forging and cold forging with different forging directions. First, a billet is provided and heated to a temperature above the recrystallization temperature. This is followed by closed-die hot forging with a first demolding direction ({right arrow over (rg)}), to obtain a hot forged part. The hot forged part is then cooled and clamped in a forming tool. This is followed by cold forging of the hot forged part, wherein a second demolding direction ({right arrow over (rk)}) during cold forging is different from the first demolding direction ({right arrow over (rg)}) during closed-die hot forging. Furthermore, the disclosure relates to a corresponding component.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to German Application No. DE102025111560.5, filed Mar. 25, 2025, the disclosure of which is hereby incorporated in its entirety by reference herein.TECHNICAL FIELD

[0002] The present invention relates to a combination of methods for producing components by hot and cold forging with different forging directions, as well as to a component produced by such a method.BACKGROUND

[0003] The production of components by closed-die hot forging is generally known from the prior art. As a method of hot working, it takes place at temperatures above the recrystallization temperature, which allows components with a complex geometry and high plastic strain to be produced. However, due to shrinkage, draft angles and a relatively large machining allowance are necessary. The depth of cup contours is limited depending on the diameter.

[0004] If a component is needed that has an undercut, this is not possible through normal closed-die hot forging. A multidirectional hot forging tool is required for this. However, the tools for this are complex, and the cycle time for the method is long.

[0005] Furthermore, other problems arise. For example, the edge of the cup can rise unevenly. This could be corrected with a spring-loaded hold-down device, which however incurs higher costs. Another problem is that an unwanted burr can form if material flows into the tool partition.

[0006] Besides closed-die hot forging, cold forging is also a well-known method from the prior art. Pressed parts that are produced by cold forging are characterized by high dimensional and shape accuracy. Furthermore, no or only very minimal draft angles are required, which means that machining allowances can be kept very small. However, compared to closed-die hot forging, the design freedom of the pressed parts is limited in cold forging. This is due to the limited deformation capacity of the material and the high flow stress of the component, which on the one hand leads to high tool loads and on the other hand limits the deformation capacity of the workpiece. However, deep cup geometries without a draft angle can be achieved through cold forging in the form of backward cup extrusion.

[0007] A combination of methods of closed-die hot forging and subsequent cold calibration are also known from the prior art. In so doing, certain surfaces on the hot forged component are brought within tight tolerances (calibration) or the wall thickness is partially reduced (coining).

[0008] With the aid of known methods, a wide range of different components can be produced economically. However, there are component geometries that cannot be produced near net shape by any of the above-mentioned methods or combinations of methods so that considerable effort is often still required during final machining.SUMMARY

[0009] The object of the present disclosure is to provide a more economical solution for producing components of the generic type, which is improved or at least represents an alternative embodiment. The invention seeks to reduce the raw material weight and subsequent machining effort of complex components with multidirectional demolding directions. This results in advantages in terms of costs and the CO2 footprint.

[0010] The object is achieved by the subject matter of the independent claims. Advantageous developments of the disclosure are specified in the dependent claims, the description and the accompanying figures. In particular, the independent claims of one claim category can also be developed analogously to the dependent claims of another claim category.

[0011] A billet is provided for producing a component of non-ferrous metal. The billet is heated to a temperature above the recrystallization temperature. Closed-die hot forging with a first demolding direction is used to obtain a hot forged part. After closed-die hot forging, the hot forged part is cooled. The cooled hot forged part is clamped in a forming tool. The hot forged part is cold forged, wherein the second demolding direction during cold forging differs from the first demolding direction during closed-die hot forging.

[0012] One advantage of closed-die hot forging is that components with a high plastic strain and complex geometry can be produced. To maintain the geometry of the hot forged part in the subsequent cold forging process, the component is clamped in a forming tool. The forming tool can, for example, include two forming tool halves. The forming tool can have an engraving (cavity) that corresponds to the negative shape of the hot forged part. Accordingly, the forming tool can completely enclose the hot forged part except for a region for cold forging. The forming tool can also consist of (or include) a single forming tool half or two forming tool halves and a round die. The forming tool can also enclose only a partial section of the hot forged part.

[0013] The component and the hot forged part can generally be referred to as a workpiece (in the particular process step). The demolding direction is the direction in which the workpiece is removed from the tool. It can also be understood as the direction of tool movement relative to the workpiece. The demolding direction and the forging direction of a forging stage lie on the same axis.

[0014] Closed-die hot forging is generally understood to be a method in which a workpiece is plastically deformed between two tools, the so-called dies. The dies contain the desired final shape of the workpiece as a cavity. By closing the dies and applying forces, the workpiece is brought into the desired shape. Closed-die hot forging is usually carried out in several stages until the desired geometry is achieved. In so doing, the temperature is above the recrystallization temperature.

[0015] Cold forging is generally understood to be a process in which a billet is not preheated, but is forged at room temperature.

[0016] The cold forging methods can be differentiated based on the direction of the material flow, in relation to the tool movement, into forward, backward, and transverse extrusion, as well as based on the part cross section into solid, hollow, and cup extrusion.

[0017] In the method according to the disclosure, cold forging can be carried out as backward cup extrusion. In so doing, a punch is pressed into the hot forged part while it is clamped in the forming tool. In so doing, the material rises upward between the punch and the forming tool, whereby a cup forms in the workpiece. The cup can have different geometries and does not necessarily have to be round. The punch can also be called a cup punch. The forming tool can have a locking mechanism to ensure the necessary closing force during cold forging. The closing force on the forming tool can be greater than the pressing force on the punch.

[0018] Closed-die hot forging is a type of hot working. Hot working is defined as forging at a temperature above the recrystallization temperature of the material. The recrystallization temperature is typically 0.3 to 0.4 times the melting point for pure metals and 0.5 times for alloys. For aluminum alloys of the 6000 series according to EN 573-3 / 4, closed-die hot forging can be carried out, for example, at a temperature between 350° C. and 550° C.

[0019] Closed-die hot forging can be carried out in multiple stages. It can also include stages for material pre-distribution. This can be, for example, upsetting, widening, or rising.

[0020] The axis of the demolding direction in cold forging and the axis of the demolding direction in closed-die hot forging can have an angle between 5° and 175°, preferably between 45° and 135°, particularly preferably between 60° and 120°, to each other. In many applications, the demolding direction during cold forging is perpendicular to the demolding direction during closed-die hot forging, corresponding to an angle of 90° with a tolerance range of + / −5°.

[0021] In closed-die hot forging, at least a first cup geometry is formed, and in cold forging, at least a second cup geometry is formed. Multiple cup geometries can also be formed during closed-die hot forging. Multiple cup geometries can also be formed during cold forging. Cup geometries produced by closed-die hot forging typically have a draft angle, for example in a range between 3° and 10°. Numerical values for side slopes are specified in DIN 7523, sheet 3. Cup geometries produced by cold forging, on the other hand, typically do not have a draft angle.

[0022] Closed-die hot forging can involve closed-die hot forging with flash. If closed-die hot forging with flash is used, the hot forged part must be trimmed before cold forging. Accordingly, trimming is carried out after closed-die hot forging. The trimming can be done on the same multi-stage press as the last stage or on a separate trimming press. The trimming can be done as hot trimming before cooling or as cold trimming after cooling.

[0023] The hot forged part can be cooled to a temperature below 150° C., preferably below 100° C., particularly preferably below 50° C. The component can also be cooled completely to room temperature, for example to a temperature in the range of 20° C. (especially + / −10° C.). Cooling can be done, for example, with air.

[0024] Cooling after closed-die hot forging can be done in the form of quenching. Quenching can be carried out by immersion in a suitable medium, for example by immersion in water.

[0025] Heating the billet to a temperature above the recrystallization temperature can involve solution annealing. For example, the billet can be heated in an oven and held at a predetermined temperature for a predetermined time so that the heating process also includes solution annealing. The predetermined time can be greater than 5 minutes, for example; in particular, the predetermined time can be between 5 and 180 minutes. The predetermined time can also be greater than 180 minutes, but this has no further effect on 6000 series aluminum. The predetermined temperature lies above the recrystallization temperature, for example in a range between 350° C. and 550° C.

[0026] The component can consist of (or include) light metal or a light metal alloy. Light metals are generally defined as metals and alloys whose density lies below 5.0 g / cm3, for example aluminum, titanium or magnesium.

[0027] The component can consist of (or include) aluminum or an aluminum alloy. Aluminum alloys are alloys that consist predominantly of aluminum. For example, the component can consist of an aluminum alloy of the 6000 series according to EN 573-3 / 4. The alloy group 6000 includes hardenable alloys with silicon and magnesium, for example Al Si1.2Mg0.4, Al Mg1SiCu(A), Al Mg0.7Si(A), Al Si1MgMn A), or Al Si1Mg0.8. For example, the component can consist of (or include) the aluminum alloy EN AW-6082.

[0028] The component has at least two cup geometries with two different demolding directions, wherein at least one first cup geometry of the at least two cup geometries is produced by closed-die hot forging, and at least one second cup geometry of the at least two cup geometries is produced by cold forging.

[0029] After cold forging, machining can follow. For example, machining can be carried out by turning, milling or drilling.

[0030] Closed-die hot forging achieves the necessary mass distribution, and complex geometries can be produced. During subsequent cold forging, cup geometries close to net shape can be formed without draft angles, which allows the machining effort to be reduced compared to closed-die hot forging.

[0031] Compared to multidirectional closed-die hot forging, the tools required are designed much simpler. Furthermore, in multidirectional closed-die hot forging, the demolding of the two closed-die hot forging directions must take place one after the other, which leads to long cycle times. In contrast, with the described combination of methods, the components can be produced on two high-speed presses. Furthermore, the flow behavior is better during cold forging. The edge of the cup geometry rises more evenly, and there is no risk of material flowing into the tool parting plane and creating a burr.

[0032] The component can be used in vehicles. It can be used, for example, in chassis and in braking systems.BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The inventive idea will be described in more detail below with reference to the figures. The following description should however be considered purely by way of example. The invention is defined solely by the subject matter of the claims. Advantageous exemplary embodiments of the disclosure are explained below with reference to the accompanying figures. The same reference signs are used for identical or equivalent elements. Furthermore, for the sake of easier readability and assignability, reference signs are also used for features that are not shown in the described figure. Furthermore, not all reference signs are always drawn in similar figures if these features are already clearly indicated in the preceding figures, in which:

[0034] FIG. 1 shows a (trimmed) hot forged part according to an exemplary embodiment of the present disclosure;

[0035] FIG. 2 shows a component according to an exemplary embodiment of the present disclosure;

[0036] FIGS. 3-6 show a hot forging tool and a hot forged part according to an exemplary embodiment of the present disclosure;

[0037] FIG. 7 shows a hot forged part with a flash according to an exemplary embodiment of the present disclosure;

[0038] FIG. 8 shows a (trimmed) hot forged part according to an exemplary embodiment of the present disclosure;

[0039] FIGS. 9-11 show a forming tool and a hot forged part according to an exemplary embodiment of the present disclosure;

[0040] FIGS. 12-14 show a forming tool and a component according to an exemplary embodiment of the present disclosure;

[0041] FIG. 15 shows a vehicle according to an exemplary embodiment of the present disclosure; and

[0042] FIG. 16 shows a flowchart of a method in accordance with an exemplary embodiment of the present disclosure.DETAILED DESCRIPTION

[0043] In the following exemplary embodiments, a combination of methods for producing multi-cupped forged parts is proposed, wherein the cup contours have different demolding directions.

[0044] The first demolding / cup direction is created by hot forging. After an (optional) trimming process, the second cup geometry is produced by cold forging.

[0045] Advantageously, a reduction in the amount of material used can be achieved for complex forged part geometries, in particular for such components with multidirectional demolding directions.

[0046] For example, the reduction amount of material used can be achieved by increasing the geometric complexity.

[0047] The core idea is a combination of hot forging including trimming and cold forging to produce complex geometries (until now, only the combination of methods in the sense of cold calibration after hot forging was known).

[0048] The aim is to apply the described method to forged parts with complex cup geometries (multidirectional demolding).

[0049] FIG. 1 shows, in a sectional view, a hot forged part 100 as a trimmed hot forged part 106. Trimmed means that the flash has already been removed. The trimmed hot forged part 106 has two cups 108 produced by closed-die hot forging. The cups 108 are cavities open on one side in the hot forged part 100. The two cups 108 are arranged on opposite sides of the hot forged part 100. A cup base 109 is formed between the two cups 108. Draft angles are necessary during hot forging. Therefore, the cups 108 produced by closed-die hot forging have corresponding draft angles. In the illustrated exemplary embodiment, the draft angle is 10°. The axis 205 of the demolding direction {right arrow over (rg )} during closed-die hot forging S3 is also shown (see also FIG. 16).

[0050] FIG. 2 shows, in a sectional view, a component 110 with two cups 108 produced by closed-die hot forging and one cup 112 produced by cold forging. The component 110 can be a representation of the hot forged part 100 shown in FIG. 1, which has undergone the method steps of the method shown in FIG. 16, including the step of cold forging S6. It can be seen that the cup 112 produced by cold forging has no draft angle. The axis 205 of the demolding direction {right arrow over (rg )}during closed-die hot forging and the axis 228 of the demolding direction {right arrow over (rk)} during cold forging are also shown. The angle a is the angle between the axis 205 of the demolding direction {right arrow over (rg)} during closed-die hot forging, and the axis 228 of the demolding direction {right arrow over (rk)} during cold forging 228. In the exemplary embodiment shown in FIG. 2, the angle a is 90°. The demolding direction {right arrow over (rk)} of the cup 112 produced by cold forging is therefore aligned perpendicular to the demolding direction {right arrow over (rg )} of the cups 108 produced by closed-die hot forging.

[0051] FIG. 3 shows, in a sectional view, a hot forging tool 200 and a hot forged part 100. The hot forging tool includes an upper die with a flash land 202 and a lower die with a flash land 204. If the forging process or step S3 of closed-die hot forging (see FIG. 16) is a multi-stage process, then the forging tool 200 shown in FIG. 3 can, for example, be the die for the last forging stage. The hot forged part 100 is a hot forged part with a flash 102. In closed-die hot forging with flash, the billet is almost completely enclosed by the tool, wherein excess material can flow away through the flash gap. The axis 205 of the demolding direction {right arrow over (rg)} during closed-die hot forging is also shown.

[0052] FIG. 4 shows, in a sectional view, a hot forging tool 200 and a hot forged part 100. The hot forging tool includes an upper die 206 and a lower die 208. The hot forged part 100 is a flash-free hot forged part 104. In closed-die hot forging without flash, the billet is completely enclosed by the tool during forging, and no material escapes from the tool during forging. The basic process of the forging corresponds to closed-die hot forging with flash. The axis 205 of the demolding direction {right arrow over (rg)} during closed-die hot forging is also shown.

[0053] FIG. 5 shows, in a sectional view, a forging tool 200 in the open state and a hot forged part 100, and the axis 205 of the demolding direction {right arrow over (rg)} during closed-die hot forging. The hot forging tool 200 includes an upper die with a flash land 202 and a lower die with a flash land 204. The hot forged part 100 is a hot forged part with flash 102. The hot forged part with a flash 102 has two cups 108 produced by closed-die hot forging.

[0054] FIG. 6 shows a spatial representation of a hot forging tool 200 and a hot forged part 100 according to the exemplary embodiment of the present disclosure shown in FIG. 3 and FIG. 5. The hot forging tool 200 includes an upper die with a flash land 202 and a lower die with a flash land 204. The hot forged part 100 is a hot forged part with a flash 102.

[0055] FIG. 7 shows a spatial representation of a hot forged part 100 as a hot forged part with a flash 102, according to the exemplary embodiment of the present disclosure shown in FIG. 6. It has a flash 103 and a cup 108.

[0056] FIG. 8 shows a spatial representation of a hot forged part 100 in the trimmed state 106, according to the exemplary embodiment of the present disclosure shown in FIG. 7.

[0057] FIGS. 9 to 14 below show various method steps of an exemplary embodiment in which a hot forged part 100 is clamped into a forming tool 220, and then the component 110 is forged by cold forging.

[0058] FIG. 9 shows a forming tool 220 in the open state and a hot forged part 100 in the trimmed state 106. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224.

[0059] FIG. 10 shows, according to the exemplary embodiment of the present disclosure shown in FIG. 9, a forming tool 220 in the closed state and a hot forged part 100 in the trimmed state 106. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224. The hot forged part 100 in the trimmed state 106 is enclosed by the forming tool 220.

[0060] FIG. 11 shows, in a sectional view, a forming tool 220 and a hot forged part 100 as a trimmed hot forged part 106. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224. The hot forged part 100 in the trimmed state 106 is enclosed by the forming tool 220. A punch 226 is shown, which is movable on the axis 228 of the demolding direction {right arrow over (rk)} during cold forging.

[0061] FIG. 12 shows, in a sectional view, a forming tool 220 and a component 110. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224. The punch has already formed a cup (second cup geometry 112) in the hot forged part 100 so that the component 110 has been created.

[0062] FIG. 13 shows, in a sectional view, a forming tool 220 and a component 110. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224. The punch 226 has already been completely withdrawn from the forming tool 220.

[0063] FIG. 14 shows, in a sectional view, a forming tool 220 in the open state and a component 110. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224.

[0064] FIG. 15 schematically shows a vehicle 300 with a component 110. In one exemplary embodiment, the component 110 is a chassis component. In an alternative exemplary embodiment, the component 110 is a component of a braking system of a vehicle 300.

[0065] FIG. 16 shows a flowchart of a method according to an exemplary embodiment of the present disclosure. The method provides the steps of providing S1 a billet, heating S2 the billet, closed-die hot forging S3, cooling S4, clamping S5 in a forming tool 220, as well as cold forging S6. In the step of heating S2, the billet is heated to a temperature above the recrystallization temperature. The recrystallization temperature depends on the material of the billet. In this case, a distance from the melting temperature above is maintained. From an energy perspective, it can be beneficial to heat only slightly, for example 5° C. to 10° C., above the recrystallization temperature. In the step of closed-die hot forging S3, the billet is forged into a forged part 100. The hot forged part 100 has a first demolding direction {right arrow over (rg)}. In the subsequent step of cooling S4, the hot forged part 100 is cooled to a temperature suitable for cold forging, for example to a temperature between 150° C. and 20° C. (corresponding to room temperature). The step of cooling S4 can extend in time over the step of clamping S5 or be completed before executing the step of clamping S5. In the step of clamping S5, the hot forged part 100 is clamped in a forming tool 220. Then the step of cold forging S6 of the hot forged part 100 follows. The tool (forming tool 220) then opens, and component 110 is demolded. A second demolding direction {right arrow over (rk)} during cold forging S6 differs from the first demolding direction {right arrow over (rg)} in the step of closed-die hot forging S3.

[0066] In the illustrated exemplary embodiment, the steps S1 to S6 are performed in the specified order. Further optional steps can be performed between or during the described method steps. For example, solution annealing could optionally be performed in the step of heating S2.

[0067] Hardenable aluminum alloys obtain their strength through the steps of solution annealing, quenching, and aging. The formed parts are solution annealed at temperatures around 500° C. and then quenched. The parts are then aged at room temperature or a higher temperature, depending on the alloy. If the aging takes place at room temperature, this process is called cold aging. If it takes place at an elevated temperature (approx. 100° C. to 200° C.), this is called artificial aging. The alloys of the 6000 series, which are typical for automobile production, are usually aged hot.

[0068] Despite the higher price (based on mass), forged aluminum is increasingly becoming the preferred material for structural components compared to steel or cast components. Forged aluminum achieves the highest strengths with very good toughness. At about one-third the density of cast iron materials, it achieves the same strengths with higher ductility. Other positive properties include good corrosion resistance. Titanium has even greater lightweight potential than aluminum but is significantly more expensive to procure and process. Forged titanium is therefore only used sporadically.

[0069] The billets are usually cut using sawing. Shear cutting, as is common in steel forging, is rarely employed due to the high ductility of the aluminum material since shear burrs would form that could be subsequently forged into the component surface during later stages of the process. Following any preliminary shaping intended to redistribute the material, the parts undergo forming within the die's pre-forming (pre-engraving) and finishing cavities (final engraving). Any excess material is then trimmed. During forging, the critical temperature of the aluminum alloy must be taken into account. For example, this is 500° C. for AlCuMg (2000 series alloy). Exceeding this limit can result in structural damage to the material. Since the flow stress kf increases by a factor of approximately 1.3 for every tenfold increase in the forging speed in the range of typical forging temperatures, the forging speed and the forging forces are adjusted to this temperature. Large and complex forged pieces, and those made from aluminum alloys difficult to forge and also sensitive to overheating, are therefore almost exclusively forged with hydraulic forging presses. These have the advantage that the forging speed can be easily adjusted. Forged pieces made from easily forgeable alloys less critical with regard to exceeding the forging temperature, such as AlMgSi (6000 series alloy), are also hot forged using forging hammers or closed-die hot forged using mechanical presses.

[0070] The lubrication of the tools is of great importance due to the high friction between aluminum and tool steel. For example, lubrication can be achieved using graphite suspended in oil or water.

[0071] If forging takes place at room temperature, it is called cold forging. Since no shrinkage occurs, the shape and dimensional stability of cold-forged components is greater than that of comparable hot forged pieces. The design freedom of pressed parts in cold forging is limited in comparison to hot forging due to the limited deformation capacity of the component material and due to the high flow stress of the component, which leads to high tool loads. As with forged components, the fiber orientation is more favorable in cold-forged pressed parts than in machined parts. In contrast to work hardening, the fiber orientation is retained after heat treatment processes. The increase in fatigue strength can be up to one third with the same material through optimized fiber orientation.

[0072] In comparison to steel, non-ferrous metals are used in a significantly smaller amount for forging production processes. Aluminum, copper, titanium, nickel, magnesium, cobalt, tungsten and their alloys are of technical importance. Depending on the material, forging takes place at suitable temperatures, wherein material-specific flow stresses and forming capacity must be taken into account.

[0073] Predominantly hardenable wrought alloys are used for the hot forging of aluminum. These are distinguished by very good corrosion resistance and good low-temperature performance. Hot forged aluminum parts are primarily used where low component weight and high operational strength are desired, e.g., in aircraft and vehicle construction.

[0074] As required, detailed embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0075] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.LIST OF REFERENCE SIGNS100 Hot forged part

[0077] 102 Hot forged part with flash

[0078] 103 Flash

[0079] 104 Hot forged part without flash

[0080] 106 Hot forged part trimmed

[0081] 108 First cup geometry (produced by closed-die hot forging)

[0082] 109 Cup base

[0083] 110 Component

[0084] 112 Second cup geometry (produced by cold forging)

[0085] 200 Hot forging tool

[0086] 202 Upper die with flash land

[0087] 204 Lower die with flash land

[0088] 205 Axis of demolding direction in closed-die hot forging

[0089] 206 Upper die

[0090] 208 Lower die

[0091] 220 Forming tool

[0092] 222 First forming tool part

[0093] 224 Second forming tool part

[0094] 226 Punch

[0095] 228 Axis of demolding direction in cold forging

[0096] a Angle

[0097] {right arrow over (rg)} Demolding direction, closed-die hot forging

[0098] {right arrow over (rk)} Demolding direction, cold forging

[0099] S1-S6 Method steps:

[0100] S1 Providing

[0101] S2 Heating

[0102] S3 Closed-die hot forging

[0103] S4 Cooling

[0104] S5 Clamping

[0105] S6 Cold forging

Examples

Embodiment Construction

[0043]In the following exemplary embodiments, a combination of methods for producing multi-cupped forged parts is proposed, wherein the cup contours have different demolding directions.

[0044]The first demolding / cup direction is created by hot forging. After an (optional) trimming process, the second cup geometry is produced by cold forging.

[0045]Advantageously, a reduction in the amount of material used can be achieved for complex forged part geometries, in particular for such components with multidirectional demolding directions.

[0046]For example, the reduction amount of material used can be achieved by increasing the geometric complexity.

[0047]The core idea is a combination of hot forging including trimming and cold forging to produce complex geometries (until now, only the combination of methods in the sense of cold calibration after hot forging was known).

[0048]The aim is to apply the described method to forged parts with complex cup geometries (multidirectional demolding).

[0049...

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to German Application No. DE102025111560.5, filed Mar. 25, 2025, the disclosure of which is hereby incorporated in its entirety by reference herein.TECHNICAL FIELD

[0002] The present invention relates to a combination of methods for producing components by hot and cold forging with different forging directions, as well as to a component produced by such a method.BACKGROUND

[0003] The production of components by closed-die hot forging is generally known from the prior art. As a method of hot working, it takes place at temperatures above the recrystallization temperature, which allows components with a complex geometry and high plastic strain to be produced. However, due to shrinkage, draft angles and a relatively large machining allowance are necessary. The depth of cup contours is limited depending on the diameter.

[0004] If a component is needed that has an undercut, this is not possible through normal closed-die hot forging. A multidirectional hot forging tool is required for this. However, the tools for this are complex, and the cycle time for the method is long.

[0005] Furthermore, other problems arise. For example, the edge of the cup can rise unevenly. This could be corrected with a spring-loaded hold-down device, which however incurs higher costs. Another problem is that an unwanted burr can form if material flows into the tool partition.

[0006] Besides closed-die hot forging, cold forging is also a well-known method from the prior art. Pressed parts that are produced by cold forging are characterized by high dimensional and shape accuracy. Furthermore, no or only very minimal draft angles are required, which means that machining allowances can be kept very small. However, compared to closed-die hot forging, the design freedom of the pressed parts is limited in cold forging. This is due to the limited deformation capacity of the material and the high flow stress of the component, which on the one hand leads to high tool loads and on the other hand limits the deformation capacity of the workpiece. However, deep cup geometries without a draft angle can be achieved through cold forging in the form of backward cup extrusion.

[0007] A combination of methods of closed-die hot forging and subsequent cold calibration are also known from the prior art. In so doing, certain surfaces on the hot forged component are brought within tight tolerances (calibration) or the wall thickness is partially reduced (coining).

[0008] With the aid of known methods, a wide range of different components can be produced economically. However, there are component geometries that cannot be produced near net shape by any of the above-mentioned methods or combinations of methods so that considerable effort is often still required during final machining.SUMMARY

[0009] The object of the present disclosure is to provide a more economical solution for producing components of the generic type, which is improved or at least represents an alternative embodiment. The invention seeks to reduce the raw material weight and subsequent machining effort of complex components with multidirectional demolding directions. This results in advantages in terms of costs and the CO2 footprint.

[0010] The object is achieved by the subject matter of the independent claims. Advantageous developments of the disclosure are specified in the dependent claims, the description and the accompanying figures. In particular, the independent claims of one claim category can also be developed analogously to the dependent claims of another claim category.

[0011] A billet is provided for producing a component of non-ferrous metal. The billet is heated to a temperature above the recrystallization temperature. Closed-die hot forging with a first demolding direction is used to obtain a hot forged part. After closed-die hot forging, the hot forged part is cooled. The cooled hot forged part is clamped in a forming tool. The hot forged part is cold forged, wherein the second demolding direction during cold forging differs from the first demolding direction during closed-die hot forging.

[0012] One advantage of closed-die hot forging is that components with a high plastic strain and complex geometry can be produced. To maintain the geometry of the hot forged part in the subsequent cold forging process, the component is clamped in a forming tool. The forming tool can, for example, include two forming tool halves. The forming tool can have an engraving (cavity) that corresponds to the negative shape of the hot forged part. Accordingly, the forming tool can completely enclose the hot forged part except for a region for cold forging. The forming tool can also consist of (or include) a single forming tool half or two forming tool halves and a round die. The forming tool can also enclose only a partial section of the hot forged part.

[0013] The component and the hot forged part can generally be referred to as a workpiece (in the particular process step). The demolding direction is the direction in which the workpiece is removed from the tool. It can also be understood as the direction of tool movement relative to the workpiece. The demolding direction and the forging direction of a forging stage lie on the same axis.

[0014] Closed-die hot forging is generally understood to be a method in which a workpiece is plastically deformed between two tools, the so-called dies. The dies contain the desired final shape of the workpiece as a cavity. By closing the dies and applying forces, the workpiece is brought into the desired shape. Closed-die hot forging is usually carried out in several stages until the desired geometry is achieved. In so doing, the temperature is above the recrystallization temperature.

[0015] Cold forging is generally understood to be a process in which a billet is not preheated, but is forged at room temperature.

[0016] The cold forging methods can be differentiated based on the direction of the material flow, in relation to the tool movement, into forward, backward, and transverse extrusion, as well as based on the part cross section into solid, hollow, and cup extrusion.

[0017] In the method according to the disclosure, cold forging can be carried out as backward cup extrusion. In so doing, a punch is pressed into the hot forged part while it is clamped in the forming tool. In so doing, the material rises upward between the punch and the forming tool, whereby a cup forms in the workpiece. The cup can have different geometries and does not necessarily have to be round. The punch can also be called a cup punch. The forming tool can have a locking mechanism to ensure the necessary closing force during cold forging. The closing force on the forming tool can be greater than the pressing force on the punch.

[0018] Closed-die hot forging is a type of hot working. Hot working is defined as forging at a temperature above the recrystallization temperature of the material. The recrystallization temperature is typically 0.3 to 0.4 times the melting point for pure metals and 0.5 times for alloys. For aluminum alloys of the 6000 series according to EN 573-3 / 4, closed-die hot forging can be carried out, for example, at a temperature between 350° C. and 550° C.

[0019] Closed-die hot forging can be carried out in multiple stages. It can also include stages for material pre-distribution. This can be, for example, upsetting, widening, or rising.

[0020] The axis of the demolding direction in cold forging and the axis of the demolding direction in closed-die hot forging can have an angle between 5° and 175°, preferably between 45° and 135°, particularly preferably between 60° and 120°, to each other. In many applications, the demolding direction during cold forging is perpendicular to the demolding direction during closed-die hot forging, corresponding to an angle of 90° with a tolerance range of + / −5°.

[0021] In closed-die hot forging, at least a first cup geometry is formed, and in cold forging, at least a second cup geometry is formed. Multiple cup geometries can also be formed during closed-die hot forging. Multiple cup geometries can also be formed during cold forging. Cup geometries produced by closed-die hot forging typically have a draft angle, for example in a range between 3° and 10°. Numerical values for side slopes are specified in DIN 7523, sheet 3. Cup geometries produced by cold forging, on the other hand, typically do not have a draft angle.

[0022] Closed-die hot forging can involve closed-die hot forging with flash. If closed-die hot forging with flash is used, the hot forged part must be trimmed before cold forging. Accordingly, trimming is carried out after closed-die hot forging. The trimming can be done on the same multi-stage press as the last stage or on a separate trimming press. The trimming can be done as hot trimming before cooling or as cold trimming after cooling.

[0023] The hot forged part can be cooled to a temperature below 150° C., preferably below 100° C., particularly preferably below 50° C. The component can also be cooled completely to room temperature, for example to a temperature in the range of 20° C. (especially + / −10° C.). Cooling can be done, for example, with air.

[0024] Cooling after closed-die hot forging can be done in the form of quenching. Quenching can be carried out by immersion in a suitable medium, for example by immersion in water.

[0025] Heating the billet to a temperature above the recrystallization temperature can involve solution annealing. For example, the billet can be heated in an oven and held at a predetermined temperature for a predetermined time so that the heating process also includes solution annealing. The predetermined time can be greater than 5 minutes, for example; in particular, the predetermined time can be between 5 and 180 minutes. The predetermined time can also be greater than 180 minutes, but this has no further effect on 6000 series aluminum. The predetermined temperature lies above the recrystallization temperature, for example in a range between 350° C. and 550° C.

[0026] The component can consist of (or include) light metal or a light metal alloy. Light metals are generally defined as metals and alloys whose density lies below 5.0 g / cm3, for example aluminum, titanium or magnesium.

[0027] The component can consist of (or include) aluminum or an aluminum alloy. Aluminum alloys are alloys that consist predominantly of aluminum. For example, the component can consist of an aluminum alloy of the 6000 series according to EN 573-3 / 4. The alloy group 6000 includes hardenable alloys with silicon and magnesium, for example Al Si1.2Mg0.4, Al Mg1SiCu(A), Al Mg0.7Si(A), Al Si1MgMn A), or Al Si1Mg0.8. For example, the component can consist of (or include) the aluminum alloy EN AW-6082.

[0028] The component has at least two cup geometries with two different demolding directions, wherein at least one first cup geometry of the at least two cup geometries is produced by closed-die hot forging, and at least one second cup geometry of the at least two cup geometries is produced by cold forging.

[0029] After cold forging, machining can follow. For example, machining can be carried out by turning, milling or drilling.

[0030] Closed-die hot forging achieves the necessary mass distribution, and complex geometries can be produced. During subsequent cold forging, cup geometries close to net shape can be formed without draft angles, which allows the machining effort to be reduced compared to closed-die hot forging.

[0031] Compared to multidirectional closed-die hot forging, the tools required are designed much simpler. Furthermore, in multidirectional closed-die hot forging, the demolding of the two closed-die hot forging directions must take place one after the other, which leads to long cycle times. In contrast, with the described combination of methods, the components can be produced on two high-speed presses. Furthermore, the flow behavior is better during cold forging. The edge of the cup geometry rises more evenly, and there is no risk of material flowing into the tool parting plane and creating a burr.

[0032] The component can be used in vehicles. It can be used, for example, in chassis and in braking systems.BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The inventive idea will be described in more detail below with reference to the figures. The following description should however be considered purely by way of example. The invention is defined solely by the subject matter of the claims. Advantageous exemplary embodiments of the disclosure are explained below with reference to the accompanying figures. The same reference signs are used for identical or equivalent elements. Furthermore, for the sake of easier readability and assignability, reference signs are also used for features that are not shown in the described figure. Furthermore, not all reference signs are always drawn in similar figures if these features are already clearly indicated in the preceding figures, in which:

[0034] FIG. 1 shows a (trimmed) hot forged part according to an exemplary embodiment of the present disclosure;

[0035] FIG. 2 shows a component according to an exemplary embodiment of the present disclosure;

[0036] FIGS. 3-6 show a hot forging tool and a hot forged part according to an exemplary embodiment of the present disclosure;

[0037] FIG. 7 shows a hot forged part with a flash according to an exemplary embodiment of the present disclosure;

[0038] FIG. 8 shows a (trimmed) hot forged part according to an exemplary embodiment of the present disclosure;

[0039] FIGS. 9-11 show a forming tool and a hot forged part according to an exemplary embodiment of the present disclosure;

[0040] FIGS. 12-14 show a forming tool and a component according to an exemplary embodiment of the present disclosure;

[0041] FIG. 15 shows a vehicle according to an exemplary embodiment of the present disclosure; and

[0042] FIG. 16 shows a flowchart of a method in accordance with an exemplary embodiment of the present disclosure.DETAILED DESCRIPTION

[0043] In the following exemplary embodiments, a combination of methods for producing multi-cupped forged parts is proposed, wherein the cup contours have different demolding directions.

[0044] The first demolding / cup direction is created by hot forging. After an (optional) trimming process, the second cup geometry is produced by cold forging.

[0045] Advantageously, a reduction in the amount of material used can be achieved for complex forged part geometries, in particular for such components with multidirectional demolding directions.

[0046] For example, the reduction amount of material used can be achieved by increasing the geometric complexity.

[0047] The core idea is a combination of hot forging including trimming and cold forging to produce complex geometries (until now, only the combination of methods in the sense of cold calibration after hot forging was known).

[0048] The aim is to apply the described method to forged parts with complex cup geometries (multidirectional demolding).

[0049] FIG. 1 shows, in a sectional view, a hot forged part 100 as a trimmed hot forged part 106. Trimmed means that the flash has already been removed. The trimmed hot forged part 106 has two cups 108 produced by closed-die hot forging. The cups 108 are cavities open on one side in the hot forged part 100. The two cups 108 are arranged on opposite sides of the hot forged part 100. A cup base 109 is formed between the two cups 108. Draft angles are necessary during hot forging. Therefore, the cups 108 produced by closed-die hot forging have corresponding draft angles. In the illustrated exemplary embodiment, the draft angle is 10°. The axis 205 of the demolding direction {right arrow over (rg )} during closed-die hot forging S3 is also shown (see also FIG. 16).

[0050] FIG. 2 shows, in a sectional view, a component 110 with two cups 108 produced by closed-die hot forging and one cup 112 produced by cold forging. The component 110 can be a representation of the hot forged part 100 shown in FIG. 1, which has undergone the method steps of the method shown in FIG. 16, including the step of cold forging S6. It can be seen that the cup 112 produced by cold forging has no draft angle. The axis 205 of the demolding direction {right arrow over (rg )}during closed-die hot forging and the axis 228 of the demolding direction {right arrow over (rk)} during cold forging are also shown. The angle a is the angle between the axis 205 of the demolding direction {right arrow over (rg)} during closed-die hot forging, and the axis 228 of the demolding direction {right arrow over (rk)} during cold forging 228. In the exemplary embodiment shown in FIG. 2, the angle a is 90°. The demolding direction {right arrow over (rk)} of the cup 112 produced by cold forging is therefore aligned perpendicular to the demolding direction {right arrow over (rg )} of the cups 108 produced by closed-die hot forging.

[0051] FIG. 3 shows, in a sectional view, a hot forging tool 200 and a hot forged part 100. The hot forging tool includes an upper die with a flash land 202 and a lower die with a flash land 204. If the forging process or step S3 of closed-die hot forging (see FIG. 16) is a multi-stage process, then the forging tool 200 shown in FIG. 3 can, for example, be the die for the last forging stage. The hot forged part 100 is a hot forged part with a flash 102. In closed-die hot forging with flash, the billet is almost completely enclosed by the tool, wherein excess material can flow away through the flash gap. The axis 205 of the demolding direction {right arrow over (rg)} during closed-die hot forging is also shown.

[0052] FIG. 4 shows, in a sectional view, a hot forging tool 200 and a hot forged part 100. The hot forging tool includes an upper die 206 and a lower die 208. The hot forged part 100 is a flash-free hot forged part 104. In closed-die hot forging without flash, the billet is completely enclosed by the tool during forging, and no material escapes from the tool during forging. The basic process of the forging corresponds to closed-die hot forging with flash. The axis 205 of the demolding direction {right arrow over (rg)} during closed-die hot forging is also shown.

[0053] FIG. 5 shows, in a sectional view, a forging tool 200 in the open state and a hot forged part 100, and the axis 205 of the demolding direction {right arrow over (rg)} during closed-die hot forging. The hot forging tool 200 includes an upper die with a flash land 202 and a lower die with a flash land 204. The hot forged part 100 is a hot forged part with flash 102. The hot forged part with a flash 102 has two cups 108 produced by closed-die hot forging.

[0054] FIG. 6 shows a spatial representation of a hot forging tool 200 and a hot forged part 100 according to the exemplary embodiment of the present disclosure shown in FIG. 3 and FIG. 5. The hot forging tool 200 includes an upper die with a flash land 202 and a lower die with a flash land 204. The hot forged part 100 is a hot forged part with a flash 102.

[0055] FIG. 7 shows a spatial representation of a hot forged part 100 as a hot forged part with a flash 102, according to the exemplary embodiment of the present disclosure shown in FIG. 6. It has a flash 103 and a cup 108.

[0056] FIG. 8 shows a spatial representation of a hot forged part 100 in the trimmed state 106, according to the exemplary embodiment of the present disclosure shown in FIG. 7.

[0057] FIGS. 9 to 14 below show various method steps of an exemplary embodiment in which a hot forged part 100 is clamped into a forming tool 220, and then the component 110 is forged by cold forging.

[0058] FIG. 9 shows a forming tool 220 in the open state and a hot forged part 100 in the trimmed state 106. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224.

[0059] FIG. 10 shows, according to the exemplary embodiment of the present disclosure shown in FIG. 9, a forming tool 220 in the closed state and a hot forged part 100 in the trimmed state 106. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224. The hot forged part 100 in the trimmed state 106 is enclosed by the forming tool 220.

[0060] FIG. 11 shows, in a sectional view, a forming tool 220 and a hot forged part 100 as a trimmed hot forged part 106. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224. The hot forged part 100 in the trimmed state 106 is enclosed by the forming tool 220. A punch 226 is shown, which is movable on the axis 228 of the demolding direction {right arrow over (rk)} during cold forging.

[0061] FIG. 12 shows, in a sectional view, a forming tool 220 and a component 110. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224. The punch has already formed a cup (second cup geometry 112) in the hot forged part 100 so that the component 110 has been created.

[0062] FIG. 13 shows, in a sectional view, a forming tool 220 and a component 110. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224. The punch 226 has already been completely withdrawn from the forming tool 220.

[0063] FIG. 14 shows, in a sectional view, a forming tool 220 in the open state and a component 110. The forming tool 220 includes a first forming tool part 222 and a second forming tool part 224.

[0064] FIG. 15 schematically shows a vehicle 300 with a component 110. In one exemplary embodiment, the component 110 is a chassis component. In an alternative exemplary embodiment, the component 110 is a component of a braking system of a vehicle 300.

[0065] FIG. 16 shows a flowchart of a method according to an exemplary embodiment of the present disclosure. The method provides the steps of providing S1 a billet, heating S2 the billet, closed-die hot forging S3, cooling S4, clamping S5 in a forming tool 220, as well as cold forging S6. In the step of heating S2, the billet is heated to a temperature above the recrystallization temperature. The recrystallization temperature depends on the material of the billet. In this case, a distance from the melting temperature above is maintained. From an energy perspective, it can be beneficial to heat only slightly, for example 5° C. to 10° C., above the recrystallization temperature. In the step of closed-die hot forging S3, the billet is forged into a forged part 100. The hot forged part 100 has a first demolding direction {right arrow over (rg)}. In the subsequent step of cooling S4, the hot forged part 100 is cooled to a temperature suitable for cold forging, for example to a temperature between 150° C. and 20° C. (corresponding to room temperature). The step of cooling S4 can extend in time over the step of clamping S5 or be completed before executing the step of clamping S5. In the step of clamping S5, the hot forged part 100 is clamped in a forming tool 220. Then the step of cold forging S6 of the hot forged part 100 follows. The tool (forming tool 220) then opens, and component 110 is demolded. A second demolding direction {right arrow over (rk)} during cold forging S6 differs from the first demolding direction {right arrow over (rg)} in the step of closed-die hot forging S3.

[0066] In the illustrated exemplary embodiment, the steps S1 to S6 are performed in the specified order. Further optional steps can be performed between or during the described method steps. For example, solution annealing could optionally be performed in the step of heating S2.

[0067] Hardenable aluminum alloys obtain their strength through the steps of solution annealing, quenching, and aging. The formed parts are solution annealed at temperatures around 500° C. and then quenched. The parts are then aged at room temperature or a higher temperature, depending on the alloy. If the aging takes place at room temperature, this process is called cold aging. If it takes place at an elevated temperature (approx. 100° C. to 200° C.), this is called artificial aging. The alloys of the 6000 series, which are typical for automobile production, are usually aged hot.

[0068] Despite the higher price (based on mass), forged aluminum is increasingly becoming the preferred material for structural components compared to steel or cast components. Forged aluminum achieves the highest strengths with very good toughness. At about one-third the density of cast iron materials, it achieves the same strengths with higher ductility. Other positive properties include good corrosion resistance. Titanium has even greater lightweight potential than aluminum but is significantly more expensive to procure and process. Forged titanium is therefore only used sporadically.

[0069] The billets are usually cut using sawing. Shear cutting, as is common in steel forging, is rarely employed due to the high ductility of the aluminum material since shear burrs would form that could be subsequently forged into the component surface during later stages of the process. Following any preliminary shaping intended to redistribute the material, the parts undergo forming within the die's pre-forming (pre-engraving) and finishing cavities (final engraving). Any excess material is then trimmed. During forging, the critical temperature of the aluminum alloy must be taken into account. For example, this is 500° C. for AlCuMg (2000 series alloy). Exceeding this limit can result in structural damage to the material. Since the flow stress kf increases by a factor of approximately 1.3 for every tenfold increase in the forging speed in the range of typical forging temperatures, the forging speed and the forging forces are adjusted to this temperature. Large and complex forged pieces, and those made from aluminum alloys difficult to forge and also sensitive to overheating, are therefore almost exclusively forged with hydraulic forging presses. These have the advantage that the forging speed can be easily adjusted. Forged pieces made from easily forgeable alloys less critical with regard to exceeding the forging temperature, such as AlMgSi (6000 series alloy), are also hot forged using forging hammers or closed-die hot forged using mechanical presses.

[0070] The lubrication of the tools is of great importance due to the high friction between aluminum and tool steel. For example, lubrication can be achieved using graphite suspended in oil or water.

[0071] If forging takes place at room temperature, it is called cold forging. Since no shrinkage occurs, the shape and dimensional stability of cold-forged components is greater than that of comparable hot forged pieces. The design freedom of pressed parts in cold forging is limited in comparison to hot forging due to the limited deformation capacity of the component material and due to the high flow stress of the component, which leads to high tool loads. As with forged components, the fiber orientation is more favorable in cold-forged pressed parts than in machined parts. In contrast to work hardening, the fiber orientation is retained after heat treatment processes. The increase in fatigue strength can be up to one third with the same material through optimized fiber orientation.

[0072] In comparison to steel, non-ferrous metals are used in a significantly smaller amount for forging production processes. Aluminum, copper, titanium, nickel, magnesium, cobalt, tungsten and their alloys are of technical importance. Depending on the material, forging takes place at suitable temperatures, wherein material-specific flow stresses and forming capacity must be taken into account.

[0073] Predominantly hardenable wrought alloys are used for the hot forging of aluminum. These are distinguished by very good corrosion resistance and good low-temperature performance. Hot forged aluminum parts are primarily used where low component weight and high operational strength are desired, e.g., in aircraft and vehicle construction.

[0074] As required, detailed embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0075] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.LIST OF REFERENCE SIGNS100 Hot forged part

[0077] 102 Hot forged part with flash

[0078] 103 Flash

[0079] 104 Hot forged part without flash

[0080] 106 Hot forged part trimmed

[0081] 108 First cup geometry (produced by closed-die hot forging)

[0082] 109 Cup base

[0083] 110 Component

[0084] 112 Second cup geometry (produced by cold forging)

[0085] 200 Hot forging tool

[0086] 202 Upper die with flash land

[0087] 204 Lower die with flash land

[0088] 205 Axis of demolding direction in closed-die hot forging

[0089] 206 Upper die

[0090] 208 Lower die

[0091] 220 Forming tool

[0092] 222 First forming tool part

[0093] 224 Second forming tool part

[0094] 226 Punch

[0095] 228 Axis of demolding direction in cold forging

[0096] a Angle

[0097] {right arrow over (rg)} Demolding direction, closed-die hot forging

[0098] {right arrow over (rk)} Demolding direction, cold forging

[0099] S1-S6 Method steps:

[0100] S1 Providing

[0101] S2 Heating

[0102] S3 Closed-die hot forging

[0103] S4 Cooling

[0104] S5 Clamping

[0105] S6 Cold forging

Examples

Embodiment Construction

[0043]In the following exemplary embodiments, a combination of methods for producing multi-cupped forged parts is proposed, wherein the cup contours have different demolding directions.

[0044]The first demolding / cup direction is created by hot forging. After an (optional) trimming process, the second cup geometry is produced by cold forging.

[0045]Advantageously, a reduction in the amount of material used can be achieved for complex forged part geometries, in particular for such components with multidirectional demolding directions.

[0046]For example, the reduction amount of material used can be achieved by increasing the geometric complexity.

[0047]The core idea is a combination of hot forging including trimming and cold forging to produce complex geometries (until now, only the combination of methods in the sense of cold calibration after hot forging was known).

[0048]The aim is to apply the described method to forged parts with complex cup geometries (multidirectional demolding).

[0049...

Claims

1. A method for producing a component of a non-ferrous metal having at least the following steps:providing a billet;heating the billet to a temperature above a recrystallization temperature;closed-die hot forging with a first demolding direction ({right arrow over (rg)}) to obtain a hot-forged part;cooling the hot-forged part;clamping the hot-forged part in a forming tool; andcold forging the hot-forged part,wherein a second demolding direction ({right arrow over (rk)}) during the cold forging is different from the first demolding direction ({right arrow over (rg)}) during the closed-die hot forging, and at least one first cup geometry is formed during the closed-die hot forging and at least one second cup geometry is formed during the cold forging.

2. The method according to claim 1, wherein the cold forging is a backward cup extrusion.

3. The method according to claim 1, wherein an axis of the second demolding direction ({right arrow over (rk)}) during the cold forging and an axis of the first demolding direction ({right arrow over (rg)}) during the closed-die hot forging have an angle (a) between 5° and 175° to each other.

4. The method according to claim 1, wherein an axis of the second demolding direction ({right arrow over (rk)}) during the cold forging and an axis of the first demolding direction ({right arrow over (rg)}) during the closed-die hot forging have an angle (a) between 45° and 135° to each other.

5. The method according to claim 1, wherein an axis of the second demolding direction ({right arrow over (rk)}) during the cold forging and an axis of the first demolding direction ({right arrow over (rg)}) during the closed-die hot forging have an angle (a) between 60° and 120° to each other.

6. The method according to claim 1, wherein the closed-die hot forging is a closed-die hot forging with flash, and wherein trimming takes place after the closed-die hot forging.

7. The method according to claim 1, wherein the cooling includes cooling the hot-forged part to a temperature below 150° C.

8. The method according to claim 1, wherein the cooling includes cooling the hot-forged part to a temperature below 100° C.

9. The method according to claim 1, wherein the cooling includes cooling the hot-forged part to a temperature below 50° C.

10. The method according to claim 1, wherein the cooling after the closed-die hot forging includes quenching.

11. The method according to claim 1, wherein the heating of the billet to a temperature above the recrystallization temperature includes solution annealing.

12. The method according to claim 1, wherein the heating includes holding the billet at a predetermined temperature for a predetermined time between 5 and 180 minutes.

13. The method according to claim 1, wherein the component includes a light metal or a light metal alloy with density below 5.0 g / cm3.

14. The method according to claim 1, wherein the component includes aluminum or an aluminum alloy.

15. The method according to claim 1, further comprising a step of machining following the cold forging.

16. The method according to claim 1, wherein the cold forging includes forming cup geometries without draft angles.

17. The method according to claim 1, wherein the closed-die hot forging includes forming cup geometries with a draft angle between 3° to 10°.

18. The method according to claim 1, wherein the component is an automotive component.

19. A non-ferrous metal component comprising:at least two cup geometries with two different demolding directions, wherein at least one first cup geometry of the at least two cup geometries is produced by closed-die hot forging and has a draft angle between 3° to 10°, and at least one second cup geometry of the at least two cup geometries is produced by cold forging and has no draft angles.

20. The component according to claim 19, wherein the component is an automotive component.

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