WO2019081774A1

WO2019081774A1 - Method for producing cast parts having microchannels

Info

Publication number: WO2019081774A1
Application number: PCT/EP2018/079515
Authority: WO
Inventors: Franz-Josef Wöstmann; Jonas KLEI
Original assignee: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
Priority date: 2017-10-26
Filing date: 2018-10-26
Publication date: 2019-05-02
Also published as: EP3700697A1; EP3700697B1

Abstract

The invention relates to a method for producing a cast part (5) having at least one microchannel (6), wherein at least one fibre (2) is secured in a cavity (1.3) of a casting tool (1), such that the at least one fibre (2) extends in the cavity (1.3) at a distance from a surrounding wall of the cavity (1.3) and at least one end of the at least one fibre (2) is outside the cavity (1.3). A casting material is introduced into the cavity (1.3) and the at least one fibre (2) is encapsulated by the casting material. A cast part (5) formed from the casting material is removed from the cavity (1.3), the at least one end of the at least one fibre (2) protruding from the cast part (5). The at least one fibre (2) is pulled out of the cast part (5). The invention also relates to the cast part (5), with the at least one microchannel (6), produced using said production method and to a method for using the cast part (5), wherein a cooling medium is introduced into the at least one microchannel (6).

Description

Process for the production of castings with microchannels

The invention relates to a method for the production of castings with microchannels. Likewise, the invention relates to castings produced by the method, in particular coils comprising a cooling channel and their use.

In various technical processes, applications and components, it is necessary to dissipate excess heat and to protect components from overheating or to temper them in a targeted manner. In many applications, such as coils in electrical machines or cooling elements in batteries, in addition to the heat exchange and removal to be ensured, the available installation space for the component temperature control and the demand as close as possible to the components to be tempered are of crucial importance. In the case of coils in electric machines, cooling is achieved today, for example, by way of directional forced ventilation by means of air flow. The disadvantage here is that the Air must be flowed through the motor, whereby dirt can be registered in the engine, which lead to failure, or require maintenance measures or make additional supply options and components of the engine necessary. Furthermore, the thermal conductivity and heat capacity of air is lower than others

Cooling media, which is why this is classified as less efficient. The same problems arise in the application for cooling / tempering for batteries and other electronic components. In particular, the available space complicates the implementation of conventional cooling / Temperierkonzepten with tempering.

Cooling channels can be formed by assembling a housing of several parts. In one half of the housing while the exposed structure of the cooling channels is shown, the other housing half closes the cooling channels, or modifications of this construction described. In cast components, cooling channels can be created by means of cores, cast-in pipes or in a subsequent processing step. All variants are subject to geometric constraints, such that cooling channels are subject to a restriction in length-to-diameter ratio and shape complexity.

According to the state of the art, lost cores can furthermore be used in order to produce casting structures with complex hollow structures. Due to their low strength, the cores are subject to geometric restrictions. Thus, no arbitrary ratio between length, diameter and complexity of the cavity can be set within the cast component.

Also known are subsequently introduced into a cast component hollow structures. These are subject to strong geometric limitations in terms of length to width ratio and complexity. Also unwanted deformations can occur within the component by the reduction of residual stress during the introduction of the hollow structures.

Battery systems for electrically driven vehicles require a controllable cooling system, which is additionally implemented by the cooling system. brought weight at the expense of the range of the vehicle goes and should be minimized.

According to DE 11 2014 001 340, cooling manifolds are formed between individual laminations of a stator core.

DE 11 2012 003 041 describes the production of microchannels by means of diffusion welding and / or brazing, whereby a complete channel separation and the resistance to the prevailing operating pressure is achieved.

DE 10 2014 102 954 AI describes a micro-channel cooling fin formed from a metal plate assembly for cooling battery modules for electrically powered vehicles.

According to DE 10 2005 033 150 AI, the cooling of electrical components by means of base plate and metallic films, which are materially interconnected, so that channels with a width of 100 to 350 μιη and a depth of 30 to 150 μιη arise. The mean distance between the channels is 30 to 300 μιη.

In DE 10 2011 056 905 Al microchannels are applied in metallic surfaces and sealed by deposition. DE 11 2006 0000 160 describes the formation of microchannels by employing an ablation method and arrangement of several layers.

Object of the present invention is to enable the most efficient cooling of components, component size and weight should be kept as low as possible. Furthermore, the mentioned disadvantages of

Cooling systems are avoided according to the prior art.

The object is achieved by a production method for a casting having the features of independent claim 1. In addition, the object is achieved by a casting according to the independent claim 10 and by a

Method for using a casting according to the independent claim 11 solved. Advantageous embodiments of the invention will become apparent from the dependent claims and from the description and the figures.

In the present invention, it can be provided, in particular, to integrate or integrate cooling directly into components by means of microchannels

Cooling element or heat exchanger to size smaller than is possible according to the prior art. In particular, the production of the microchannels and their geometric design and positioning is part of the invention. With the invention, it should be possible to produce complex channels in cast components, which have a large ratio between length and diameter.

A manufacturing method is therefore directed according to this application to the production of the component as a casting with at least one microchannel. In this case, at least one fiber is fixed in a cavity of a casting tool. The fiber extends in the cavity and is at a distance from a wall of the cavity, wherein at least one end of the at least one fiber is outside the cavity. A casting material is introduced into the cavity and the at least one fiber is encapsulated by the casting material. A casting formed from the casting material is removed from the cavity, with the end of the at least one fiber protruding from the cavity protruding from the casting. The at least one fiber is pulled out of the casting at the end protruding from the casting so that where the fiber has run in the casting, a cavity forming the microchannel remains.

By using a fiber for the production of the microchannel, it is possible to design the microchannel with a complex profile, that is, for example, to generate one or more bends in the microchannel. Due to the flexibility of the fiber, it can be pulled even if it contains one or more bends or bends. Furthermore, a diameter of the channel can be kept particularly low. In the component available space can be optimally utilized. The at least one fiber may, for example, have a diameter which is about 5 μm. The diameter can also be more than 5 μιη and For example, be at most a few hundred μιη, about 500 μιη maximum.

The at least one fiber is typically at least 1 mm long. It may be that the length of the at least one fiber is at most a few hundred mm, about 500 mm at most, in order to be able to remove the fiber still well.

Also with a view to removal of the fiber, it may be provided that a bending radius of the at least one fiber, when arranged in the cavity, is at least ten times the diameter of the fiber.

Alternatively or additionally, 0.5 mm may be provided as the smallest bending radius. By such bending radii, the tearing off of the at least one fiber can be prevented.

This smallest bending radius is then reflected in the casting to be produced as the smallest bending radius of the at least one microchannel located therein.

A melting point of the at least one fiber is typically at least 1000 ° C, for example at about 1200 ° C. Alternatively or additionally, the fiber is typically chosen so that its temperature resistance is at least 750 ° C.

In the method, the at least one fiber can be clamped in a frame, for example. The frame can be positioned in the casting tool. The frame may then approximately define the cavity so that the casting material is introduced into an interior of the frame.

In the manufacturing process, aluminum casting, such as Anticorodal AC 70, is preferably used as the casting material.

But it may also be that another casting material is used, which contains, for example, aluminum and / or magnesium and / or zinc and / or lead and / or copper. So there are about alloys of the materials mentioned in question. In this case, for example, casting materials are used with melting point below 700 ° C, preferably below 600 ° C. As a casting process, for example, a low-pressure or gravity casting can be used. Hereby can be advantageously achieved that the fibers remain when filling the casting material at the intended position and also do not enter into a cohesive connection with the casting material.

However, die casting, precision casting or lost foam processes can also be used.

Both permanent molds and lost molds can be used for the casting tool.

The at least one fiber may be formed, for example, as glass fiber, such as S-glass or E-glass, carbon fiber, aramid fiber, mineral fiber or metallic fiber. These materials have been found to be particularly suitable to avoid the cohesive connection with the casting material.

The said optional further developments, taken alone or in combination, can contribute to the fact that the fibers can be pulled out of the cast component with little effort.

When removing the at least one fiber from the cast component to produce the at least one microchannel, a tensile force for pulling out the at least one fiber can be controlled or regulated. The force can thus be varied in particular during extraction to avoid tearing off the at least one fiber. This may be indicated, for example, when the fiber has a curved or angled course.

It may also be provided in possible embodiments that are used as fibers thick single fibers. However, it can also be provided that the at least one fiber comprises a plurality of fibers which are provided as yarn, hybrid yarn, fiber bundles, rovings or braid.

As a result, for example, on the one hand, a micro-channel with accordingly larger diameter can be achieved and, on the other hand, extraction can be simplified because the elements mentioned can be compressible compared to single fibers.

It is also possible that the mentioned multi-fiber yarns, hybrid yarns, fiber bundles, rovings or braids are removed by the fibers contained therein are pulled out individually.

Furthermore, hybrid yarns with outer sheath of glass fibers and a temperature-stable core of steel filaments can be used.

In this way, the properties of the fibers can be adapted to the casting process and to the requirements of the microchannels to be created.

In the following, it is explained how, if provided, a complex course for the fibers can be produced.

In one possible embodiment, at least one core mark can be provided in the cavity, wherein at least one of the at least one fiber is deflected by means of the at least one core mark.

In this case, a further step for removing the at least one core mark from the casting can be provided in the method. The core mark may be connected to the casting tool so that the core mark is removed from the tool when the casting is removed. Holes in the casting caused by the at least one core mark can then be closed, for example, before the removal of the at least one core mark, for example by introducing casting material into the holes.

Alternatively or additionally, at least one wire for fixing and / or deflecting the fiber may be provided in the cavity, wherein the at least one wire is formed of aluminum or of a material which is suitable for entering into a cohesive connection with the casting material used or in Solution to go. The wire designed in this way then connects with the casting material introduced into the cavity in a solid and media-tight manner and does not have to be removed. If the Wire is not completely in solution with the casting material, it may remain in some embodiments as a foreign body in the casting without significantly affect its performance or lead to a structural weakening of the casting. The at least one wire may be formed, for example, as a thin wire. It can be prepared inside the tool or in a tenter outside the tool.

Furthermore, it is alternatively or additionally also possible to infiltrate the at least one fiber with a temperature-stable matrix material, preferably water glass or silicate adhesive. The at least one fiber is typically introduced into a forming tool in an upstream process and infiltrated with the temperature-stable matrix material in order to produce prefabricated preforms which can assume a maximally complex shape. The fiber produced in this way is dimensionally stable and may have a curved or angled course. It may then be provided in the cavity, with the advantage that no wires or core marks or at least fewer wires and core marks are needed for the bent or angled barrel than for flexible fibers. For example, the fiber can then be fixed only by means of a frame or only by means of wires or core marks.

One degree of infiltration is chosen so that on the one hand sufficient dimensional stability exists and on the other hand the removal of the infiltrated fiber or fibers is possible by pulling out of the casting.

The invention also relates to a component, in particular cast part, with which the efficient cooling can be made possible.

The casting has at least one microchannel made in the manner described above. The casting may be formed, for example, as a coil or as a housing of a battery or an electric motor. It can also be a component of a machine tool, for example for a high-speed application, a component a power electronics, a gas turbine, a compressor, a turbine blade, a heat exchanger or a burner act.

In addition, the invention relates to the use of the casting described herein. The design of the channels made in the manner described, in particular their small diameter and typically complex shape may result in certain types of use being advantageous.

For example, in methods of using the casting, cooling media may be used that have a low boiling point and that flow through the microchannels in a gaseous manner, at least during part of the use. Liquid media suffer a considerable pressure loss in channels of small cross-section and therefore require correspondingly higher pressures, pump capacities and, consequently, a higher energy consumption when used in microchannels. This reduces the overall system in terms of efficiency and cost-effectiveness.

In the case of the microchannels shown here, the cooling medium can be selected according to the application temperatures relevant to the application.

The cooling medium is typically at a low pre-pressure at the entrance of the microchannels.

A cooling medium can be introduced, for example, in the liquid state of matter into the at least one microchannel.

It can be provided that the cooling medium changes its state of aggregation from liquid to gaseous upon heating of the component or of the cooling jacket.

As possible cooling media currently used refrigerants can be used. For example, R123a or ammonia can be used.

The boiling point of the coolant can be selectively influenced by the form. Depending on the application, refrigerants can be used for high efficiency, easy detectability, avoidance of ozone damage, etc. to be selected. The possible transition into the gaseous phase results in a high enthalpy absorption and thus a high cooling capacity. At the same time, the transition to the gaseous state results in an increase in volume, which results in an increase in pressure in the system. The gaseous cooling medium is thus driven through the cooling channel without an increase in the admission pressure.

The cooling process can also take place, for example, according to the thermosiphon or heat pipe principle or according to the principle of a refrigeration machine.

Exemplary embodiments of the invention will be explained with reference to the appended figures.

Show in it

1 shows schematically a casting tool, with a cavity in which a

Fiber is arranged,

Figure 2 shows a casting with a microchannel made with the

Casting tool of Figure 1,

FIG. 3 shows a side view and a section of the casting from FIG. 2,

FIG. 4 shows an oblique view and a section of a casting designed as a coil with a microchannel,

5 shows a casting tool in which a frame with clamped

Fibers is positioned,

FIG. 6 shows a casting produced with the casting tool from FIG. 5,

FIG. 7 shows a casting tool with a cavity and arranged therein

Core marks for deflecting a running in the cavity fiber, and 8 shows a section through a casting produced with the casting tool from FIG. 7, with a microchannel and holes caused by the core marks. FIG. 1 shows at the top a schematic representation of a fiber 2 which is positioned in a casting mold 1 shown below in the figure before a casting process. In the figure 1 is indicated by an arrow, as the fiber 2 formed fiber material is introduced into a cavity 1.3 of the tool, wherein a bending of the fiber 2 follows a course of the cavity 1.3. Thus, the fiber 2 can be arranged substantially centrally in the cavity 1.3, so that it extends from a wall of the cavity 1.3 spaced.

The fiber 2 is fixed in the cavity of the casting tool so that its ends protrude from the cavity.

Subsequently, aluminum melt, for example Anticorodal AC 70, is introduced as casting material into the cavity 1.3, so that the fiber 2, i. a portion of the fiber which lies in the cavity 1.3, is poured around the casting material.

In other embodiments, the casting material may contain magnesium and / or zinc and / or lead and / or copper instead of or in addition to aluminum.

The fiber 2 is formed as a glass fiber, for example made of S-glass or E-glass. In other embodiments, it can also be chosen as carbon fiber, aramid fiber, mineral fiber or metallic fiber.

In the example shown, the fiber 2 has been introduced into a forming tool in an upstream process and infiltrated with a temperature-stable matrix material (for example, water glass, silicate adhesive, etc.). Prefabricated preforms resulting in this way can assume a maximum complex shape and are then inserted into the casting tool. Due to the selected degree of infiltration dimensional stability of the preforms and Entform availability are achieved from the casting. The fiber 2 has a diameter of between 5 μιη uno! 500 μιη a length of at least 1 mm and at most 500 mm.

A bending radius of the fiber 2 is at least ten times the diameter of the fiber and at least 0.5 mm.

A melting point of the fiber is above 1200 ° C and a temperature resistance above 750 ° C. There is a non-wetting between fiber 2 and aluminum melt

System. As a result, cast in various casting fibers, fabrics, scrims and other semi-finished fiber products are not wetted and enter into no material connection with the aluminum. For example, fibers can be deliberately introduced into the casting process, encapsulated and then pulled out of the component again. In a subsequent process step, the fibers are pulled out of the cast component, whereby a

Micro channel is formed (see also Figures 2 and 3).

Experiments have shown, for example, that glass fibers (S-glass, E-glass) and aluminum (Anticorodal AC 70) in low-pressure and gravity casting process do not connect with each other. The fibers can then be pulled out of the cast component with a tensile tester with little effort. But it is also possible to use die-casting, precision casting or lost foam methods.

To remove the fiber from the casting member to create a microchannel, the casting is removed from the cavity and the fiber is pulled out of the casting member in a machine-aided and controlled process to prevent tearing within the component.

The use of fiber bundles or rovings or yarns or fiber yarns or braids is also possible. Furthermore, hybrid yarns with outer sheath of glass fibers and a temperature-stable core can

Steel filaments are used. FIG. 2 shows a schematic representation of the thin-walled cast part 5 with microchannel 6, the production of which was described in connection with FIG. It has the curved or curved course of the cavity 1.3 shown in FIG.

The casting 5 formed from the casting material was removed from the cavity 1.3, wherein at opposite ends of the casting 5, the fiber 2 protrudes.

One of the ends of the fiber 2 is gripped and pulled out of the casting 5 using the machine-assisted and controlled process described above.

Figure 3 shows a schematic representation of the thin-walled casting 5 with microchannel 6 of Figure 2 in a side view (top) and in a sectional view (bottom).

In the sectional view of the centrally extending in the casting 5

Microchannel 6 can be seen, which has an identical and uniform length over the length to parallel curved outer sides of the casting 5 and extends over a complete length of the casting 5 and emerges at opposite ends of the casting 5. This embodiment of the microchannel 6 is made possible by the manufacturing method described in connection with FIGS. 1 and 2.

FIG. 4 shows a casting 5 with two microchannels, which was produced by the method described above using fibers 2. On the left, the casting 5 is shown in a perspective view and on the right in a lateral sectional view, so that the microchannels 6 are visible.

The casting 5 is formed as a coil, whose turns are formed of cast aluminum wire with a flattened rectangular cross-sectional profile. Such flat configured coils are suitable to take advantage of available space particularly well. In operation, such

As a result, coils also become particularly hot, so that cooling is necessary can be. Cooling devices according to the prior art would run counter to this goal. In such cast coils for electrical machines microchannels can be introduced for the internal cooling of the individual windings with the technique described here. The microchannels shown do not require any additional components. The channels may extend along turns sections. In the example shown, two channels 6 extend parallel to each other between two opposite sides of the coil along two turns sections.

When operating components with at least one microchannel, in particular, for example, during operation of the coil shown, these can be advantageously cooled in the manner described below.

It is advantageous to use cooling media which have a low boiling point and which flow through the microchannels in gaseous form. Liquid media suffer a considerable pressure loss in channels of small cross-section and therefore require correspondingly higher pressures, pump capacities and, consequently, a higher energy consumption when used in microchannels. This reduces the overall system in terms of efficiency and cost-effectiveness. In combination with microchannels, the liquid cooling medium is selected according to the application's relevant operating temperatures. The cooling medium is at a low pre-pressure at the entrance of the microchannels. When heating the component or the cooling jacket, the cooling medium changes its state of matter from liquid to gaseous. As possible cooling media currently used refrigerants (for example R123a, ammonia) can be used, the boiling point of which can be selectively influenced by the form. Depending on the application, refrigerants can be used for high efficiency, easy detectability, avoidance of ozone damage, etc.

to be selected. The transition into the gaseous phase results in a high enthalpy absorption and thus a high cooling capacity. At the same time, the transition to the gaseous state results in an increase in volume, which results in an increase in pressure in the system. The gaseous cooling medium is thus driven through the cooling channel without an increase in the admission pressure. In addition to coils, other cast components can be provided with the shown microchannels in the manner described and then cooled in their use in the manner described. These other cast components may, for example, be a housing of a battery or of an electric motor or else a component of a machine tool, in particular for high-speed applications. It can also be a component of a power electronics, a gas turbine, a compressor, a turbine blade, a heat exchanger or a burner.

FIG. 5 shows the use of a frame 3 with clamped fibers 2 for producing the cast parts 5 with microchannels 6.

The fibers 2 are clamped in a frame 3 outside the tool (left in the figure). In the casting process, the frame 3 is inserted into the tool 1 (on the right in the figure) and the fibers 2 are encapsulated.

FIG. 5 shows how the frame 3 is positioned on a lower tool half 1.1, so that the frame itself lies outside the cavity 1.3 of the casting tool, but the fibers 2 clamped therein run through the cavity 1.3. The casting tool can then be closed by means of an upper mold half. In the casting process, which is carried out as a low pressure or gravity casting process, the fibers will be lapped with melt, which is passed into the cavity 1.3.

After removal of the casting 5 formed from the melt, the frame and portions of the fibers 2 are outside the casting. The frame can then be removed and the fibers pulled out. This can be done again in the machine-aided controlled process.

Again, the fibers may be formed not only as glass fibers but also as carbon fibers, aramid fibers, mineral fibers or metallic fibers.

FIG. 6 shows the casting 5 with a plurality of microchannels, the production of which has been described in connection with FIG. In a pouring downstream process step, the frame was removed and the glass fibers 2 were pulled out of the casting, so that where the fibers 2 have run, the microchannels 6 arise.

FIG. 7 shows a lower tool half 1.1 for producing a casting 5 mi with a microchannel, wherein core marks 4 within the tool serve as fixing or deflection points for the fiber 2 or fibers within the cavity 1.3 of the tool. The fibers are clamped outside the cavity in the tool. Optionally, the frame shown in FIG. 5 can also be used for this purpose.

The fiber 2 or a textile semifinished product can, by being stretched around the core marks 4 in the tool, image the complex path shown. In FIG. 7, the fiber is deflected three times. A bending radius of the fiber 2 steered around the core marks is at least ten times the diameter of the fiber and at least 0.5 mm.

The core marks 4 are formed so that they do not come into contact with the molten aluminum introduced and can be removed from the component after casting, or the core marks 4 can be connected to the tool so that they are removed from the casting when the casting is removed to be pulled.

Alternatively, it is also possible to provide in the cavity wires for fixing and / or redirecting the fiber, for example, exactly at the locations of the core marks shown 4. The wires may be formed of aluminum or of a material that is suitable with aluminum melt in Solution to go.

The fibers 2 are prepared by means of the, preferably thin, wires inside the tool or by means of an additional optional tenter outside the tool. In the casting process, the wires are poured in so that they form a solid and media-tight connection with the aluminum. The wires remain in the casting, while the fibers can be pulled out after the casting process. FIG. 8 shows the casting 5, which was produced with the casting tool with core marks 4 shown in FIG. After the casting process, voids remain within the cast component 5 at the locations where the core marks were located. 4. The holes are then sealed, for example by filling in additional melt. This is typically done before pulling out the fiber 2, wherein the withdrawal is advantageously regulated again, since the risk of tearing in such a bent fibers 2 may be reinforced.

LIST OF REFERENCE NUMBERS

1 casting tool

1.1 Lower tool half

1.3 cavity

2 fiber

3 frames

4 core brand

5 casting

6 micro-channel

7 holes

Claims

FRAUNHOFER SOCIETY ... E.V.

187PCT 2819

claims

Manufacturing method for a casting (5) with at least one microchannel (6), wherein

at least one fiber (2) is fixed in a cavity (1.3) of a casting tool (1) so that the at least one fiber (2) extends in the cavity (1.3) spaced from a wall of the cavity (1.3) and at least one end the at least one fiber (2) lies outside the cavity (1.3),

a casting material is introduced into the cavity (1.3) and the at least one fiber (2) is surrounded by the casting material,

a cast part (5) formed from the casting material is removed from the cavity (1.3), the at least one end of the at least one fiber (2) protruding from the cast part (5),

the at least one fiber (2) is pulled out of the casting (5).

Manufacturing method according to claim 1, wherein the at least one fiber (2) has a diameter of at least 5 μιη and / or at most 1000 μιη.

Manufacturing method according to one of the preceding claims, wherein the at least one fiber (2) has a length of at least 1 mm and / or at most 500 mm.

Manufacturing method according to one of the preceding claims, wherein a bending radius of the at least one fiber (2) is at least ten times the diameter of the fiber and / or at least 0.5 mm.

Manufacturing method according to one of the preceding claims, wherein a melting point of the at least one fiber (2) is at least 1000 ° C and / or a temperature resistance of the at least one fiber is at least 750 ° C. Production method according to one of the preceding claims, wherein the casting material is aluminum melt, preferably

Anticorodal AC 70, or the casting material contains aluminum and / or magnesium and / or zinc and / or lead and / or copper.

A manufacturing method according to any one of the preceding claims, wherein a low pressure or gravity casting method is used as the casting method or wherein a die casting, investment casting or lost foam method is used.

Manufacturing method according to one of the preceding claims, wherein the at least one fiber (2) is selected as glass fiber, carbon fiber, aramid fiber, mineral fiber or metallic fiber.

Manufacturing method according to one of the preceding claims, wherein the at least one fiber (2) comprises a plurality of fibers, which are designed as a yarn, hybrid yarn, roving, fiber bundles or braid.

Manufacturing method according to one of the preceding claims, wherein in the cavity (1.3) at least one core mark (4) is provided and at least one of the fibers (2) by means of the at least one core mark (4) is deflected.

The manufacturing method according to claim 10, wherein the method further comprises a step of closing holes (7) caused by the at least one core mark (4) in the casting (5).

Manufacturing method according to one of the preceding claims, wherein in the cavity (1.3) at least one wire for fixing and / or deflecting the fiber (2) is provided, wherein the at least one wire is formed of aluminum or of a material which is suitable Bonding with the casting material or going into solution with the casting material.

13. A manufacturing method according to one of the preceding claims, wherein the at least one fiber (2) with a temperature-stable Matrix material, preferably water glass or silicate adhesive, is infiltrated, for producing a dimensional stability for the fiber (2) with a bent or angled course.

Manufacturing method according to one of the preceding claims, wherein the at least one fiber (2) is clamped in a frame (3) and the frame (3) is positioned in the casting tool (1).

Manufacturing method according to one of the preceding claims, wherein a tensile force for pulling out the at least one fiber (2) is controlled or regulated.

Casting element (5) with at least one microchannel (6), produced according to one of the preceding claims, preferably designed as a coil or as a housing of a battery or an electric motor, or as a component of a machine tool, power electronics, a gas turbine, a compressor, a turbine blade, a heat exchanger or a burner.

A method of using a casting (5) according to claim 16, wherein a cooling medium is introduced into the at least one microchannel (6).

A method according to claim 17, wherein the cooling medium in liquid state is introduced into the at least one microchannel (6).

A method according to claim 18, wherein the cooling medium in the

Cooling channel changes its state of matter from liquid to gas.

Method according to one of claims 17 to 19, wherein the cooling medium is applied with a pre-pressure at an inlet of the at least one cooling medium.

A process according to any one of claims 17 to 20, wherein R123a or ammonia is used as the refrigerant.