TWI487618B - Laserschweissbares verbundmaterial - Google Patents

Description

Laser fused composite

The invention relates to a laser weldable composite material, in particular for a solar collector element, which comprises a strip of metal made of a highly reflective property for laser radiation (Reflektivität) The base body has a first side and a second side, wherein at least the first side has a ceramic coating.

Such a composite material is disclosed in the European patent application EP 2 239 086 A1. A known method of laser welding a composite material to a workpiece is described in the patent application, which method is used in particular for the manufacture of solar collector elements, wherein the composite material comprises a high degree of use for laser radiation. a strip-shaped substrate made of metal having a reflective property, the strip-shaped substrate having a first side and a second side, and having a ceramic coating on at least the first side, and further, to form a weld, at least a laser beam is required Projected onto the first side of the substrate with the ceramic coating, and the orientation angle of the laser beam needs to be in the form of an acute angle. In addition, the patent application file describes a laser weldable composite material for use in such a method. The method disclosed in EP 1 217 315 B1, US Pat. No. 300 591 B1, DE 38 27 297 A1, and US Pat. No. 4,023,005, which is incorporated herein by reference in its entirety, for the purpose of maintaining high functionality and manufacture of composite materials. In the case of cost savings as much as possible, the efficiency of the welding process is increased, as is the case in EP 2 239 086 A1, ie the thickness of the ceramic coating is in the range from 140 nm to 210 nm, and the laser light The beam needs to be incident at an orientation angle of between 2 and 50 degrees so that at least 15% of the incident energy of the laser beam can be absorbed.

It should be noted here that, like the phenomenon that occurs on the surface of a composite material during laser welding, when light is irradiated onto an object, the incident light is divided into a reflecting portion, an absorbing portion and a transmitting portion. For this reason, the reflectivity (reflexivity), absorption rate (absorption capacity) and transmittance (Transmissionsgrad) unique to the composite material are available not only on the first side of the composite but also on the second side. ) (transmission ability). Reflectivity, absorption and transmission are optical properties. For the same material, these optical properties have different values depending on the wavelength of the incident light (eg, ultraviolet, visible, infrared, and thermal radiation). . In order to ensure efficient use of energy, for this material, the maximum absorption rate on the first side is required in the wavelength range of the laser beam (typically 1.06 μm, more precisely, 1064 nm). If the transmittance of the composite is zero, then the sum of reflectance and absorbance will be 100%. Thus, the reflectivity of the first side of the composite material disclosed in EP 2 239 086 A1 is at least 85%.

Thus, the laser welding method has achieved higher efficiency than other similar methods, but the efficiency has room for improvement. For almost all methods currently used in the CO ₂ laser system and the Nd:YAG laser system (also described in EP 2 239 086 A1), the typical wavelength of the laser beam is 1.06 μm. At this wavelength, the unprocessed aluminum on the market and the passivated aluminum used for solar absorbers reflect only about 90% of the incident laser energy.

The basic object of the present invention is to provide a composite material of the type mentioned at the outset, in particular a composite material for solar collector elements, which is better when welding such composite materials by means of lasers. The functionality and the lowest possible production costs ensure that the efficiency of the production process can be further increased.

According to the invention, this object is achieved in that, starting from the substrate, a metal layer is provided on the ceramic coating, and the thickness of the ceramic coating and the thickness of the metal layer are designed such that the wavelength is 1064 nm. When the incident laser beam is incident at an incident angle of 65° to 80°, the total reflectance determined in accordance with DIN 5036 Part 3 on the first side of the substrate is less than 60%.

Surprisingly, the inventors have found that a composite material having a layer system according to the invention can increase the energy absorbed during laser welding by several times compared to known composite materials.

Furthermore, in particular, the thickness of the ceramic coating on the first side of the substrate may range from 20 nm to 135 nm, and the thickness of the metal layer above the ceramic coating may range from 5 nm to 25 nm.

If the dimensions of the individual layers are within the respective ranges mentioned above, the total reflectance of the laser beam having a wavelength of 1064 nm on the first side of the substrate, which is determined according to DIN 5036 part 3, may preferably be less than 50%, particularly preferably 40%. That is to say, the absorption rate of the laser beam is at least 50% or 60%, which is beneficial. By slightly varying the layer thickness within the scope of the invention, It can also be used at other wavelengths (if it is desired to use other lasers such as argon lasers (wavelength 488 nm or 515 nm) or 鈥-YAG lasers (wavelength 2123 nm)) in the same way Maximize absorption.

In a preferred embodiment the ceramic coating can be designed to be made substantially of alumina. If the matrix of the composite material is also made of aluminum, the ceramically coated alumina can be formed, in particular, from anodized or electropolished and anodized aluminum on the substrate in a technically advantageous manner.

The metal layer may preferably comprise or consist entirely of chromium and/or titanium. The thickness of the layer may preferably fall within the range of 10 nm to 20 nm, especially 15 nm. The metal layer can be applied to the ceramic coating in a continuous vacuum strip coating process in a technically advantageous manner.

The composite material according to the invention thus makes it possible to construct a web, in particular a web having a width of up to 1600 mm and a thickness in the range of from about 0.1 mm to 1.5 mm, preferably in the range of from about 0.2 to 0.8 mm, and the composite material All of the layers can be processed in a roll-to-roll (roll-to-roll) process in a continuous process.

Furthermore, the composite material according to the invention, in particular when the composite material is to be used in the manufacture of solar collector elements, can have an optically efficient multilayer system on the second side of the substrate, the multilayer system comprising at least two layers, Preferably at least three layers are included.

On the substrate, an intermediate layer can be designed under the optical multilayer system, which ensures mechanical protection and corrosion protection of the substrate on the one hand and high adhesion to the optical multilayer system on the other hand. (Haftung). Here, the intermediate layer can likewise be a ceramic layer, but it is situated above the second side of the substrate and can in particular be produced in the same manner as the ceramic coating on the first side of the substrate.

If an optically efficient multilayer system comprising at least three layers is employed, the uppermost layer may be an insulating layer, the middle layer may be a layer that primarily absorbs visible light and preferably contains chromium oxide, while the lowermost layer may be gold or silver. Made of copper, chrome, aluminum and/or molybdenum. The mirotherm® is a well-known layer system on an aluminum substrate; by means of the invention, its performance in laser welding can be significantly improved without compromising its excellent optical properties.

In order to produce a solar collector element or an absorber component, a composite material according to the invention with a base material, for example made of aluminum (with a ceramic layer made of aluminum oxide on the first substrate surface and a metal layer) can It is connected by laser welding to, for example, a tube made of copper. In this case, a material-bonding connection is formed which is formed on the one hand by aluminum which melts in the melting step and hardens again, and on the other hand by migration of aluminum into the copper. For welding, it can be carried out using, for example, a ray having a sufficient power of a CO ₂ -YAG laser or an Nd-YAG laser.

In particular, the tube and absorber parts can be joined together along their contact locations by point welds which are formed on both sides of the tube and which are formed by a pulse welding process. In this case, when the laser power and pulse frequency are determined, it should be noted that the size of the solder joint depends first on the thermal conductivity, and the surface temperature, the irradiation time, the thickness of the absorber component, and the material properties are mutually affected. the elements of. In the depth of fusion and laser There is a proportional relationship between the average powers. Since the absorption capacity of the composite material according to the invention is improved, significant power savings can be achieved in the welding process compared to the already known methods (for this, see EP 2 239 086 A1 and EP 1 217 315 B1). .

Further advantageous embodiments of the invention are contained in the dependent claims and the subsequent detailed description.

For the following description, it is emphasized that the invention is not limited to the embodiments, and thus is not limited to all or a plurality of features in the described combination of features; in fact, each individual sub-feature in any embodiment When separated from all other sub-features described in combination, whether alone or in combination with any of the features of another embodiment, it is still of inventive significance.

In the different figures, the same components, or in particular layers which serve the same function, are assigned the same reference numerals and are generally only described once in the following.

First, as shown in Fig. 1, a first embodiment of a laser weldable composite material V (especially useful for fabricating solar collector elements) according to the present invention comprises a strip-shaped metal substrate 1. The substrate has a first side A and a second side B.

On the second side B of the substrate 1 there is an intermediate layer 2 which can optionally be present and an optical multilayer system 3 which can optionally be present on the intermediate layer 2, said multilayer system comprising at least three layers 4, 5, 6 . In the optically effective multi-layer system 3, the uppermost layer 4 is an insulating layer, and the middle layer 5 is mainly sucked. The layer of visible light is applied, while the lowermost layer 6 is a metallic infrared reflective layer.

The uppermost layer 4 can in particular be an oxide layer, a fluorination layer, a vulcanization layer, a nitride layer, an oxynitride layer and/or a carbon oxynitride layer having a refractive index n<1.8. It may especially be an oxide layer of titanium, tantalum or tin having a chemical composition of TiO _z , SiO _w or SnO _v , wherein the subscripts v, w and z respectively represent stoichiometric or non-stoichiometric ratios of the oxidized component, and are Within the following range: 1<V and / or w and / or z 2, preferably 1.9 v and / or w and / or z 2. A niobium oxide layer having a chemical composition of SiOw may be preferred, wherein the value of the subscript w is 2. The thickness D4 of the uppermost layer 4 may preferably fall within the range of 3 nm to 500 nm.

The layer 5 which mainly absorbs visible light in the middle may especially comprise chromium oxide having a chemical composition of CrO _r and/or chromium nitride having a chemical composition of CrN _s and/or chromium oxynitride having a chemical composition of CrO _r N _s , wherein The labels r and s represent stoichiometric or non-stoichiometric ratios, respectively, and 0 < r and / or s < 3. This layer 5 may also be selected to contain fluorides, sulfides, nitrides, oxynitrides and/or carbon oxynitrides of other metals than chromium. Its thickness D ₅ may especially fall within the range of from 0.01 μm to about 1 μm.

The lowermost layer 6 of the optical multilayer system 3 may preferably be made of gold, silver, copper, chromium, aluminum and/or molybdenum. It may in particular have a thickness D _{6 of} a minimum of 3 nm and a maximum of about 500 nm.

On the first side A of the substrate 1, a ceramic coating 7 is present. According to the invention, the thickness D _{7 of} the ceramic coating falls within the range of 20 nm to 135 nm, while at the back of the ceramic coating 7 A metal layer 8 having a thickness D ₈ of 5 nm to 25 nm is also designed on the face of 1 (the lower portion of the ceramic coating 7 in the drawing).

The thickness D _{7 of the} ceramic coating layer 7 may preferably fall within the range of 40 nm to 95 nm, and the thickness D _{8 of the} metal layer ₈ may preferably be in the range of 10 nm to 20 nm, and particularly preferably 15 nm. The metal layer 8 may comprise or be made entirely of chromium and/or titanium.

The ceramic coating 7 on the first side A of the substrate 1 can be made substantially of alumina, wherein the substrate 1 of the composite material V according to the invention is made of aluminum. Thus, the alumina of the ceramic coating 7 can preferably be formed by anodizing or electrolytically polishing aluminum of the substrate 1 and anodizing.

The intermediate layer 2 on the second side B of the substrate 1 can also preferably be a ceramic coating 2, and can be produced in particular in the same manner as the ceramic coating 7 on the first side A of the substrate 1. In the foregoing case, that is, the ceramic coating 7 on the first face A of the substrate is made of alumina which is anodized or electropolished and anodized by aluminum of the substrate 1. The ceramic coating 2 on the second side B of the substrate 1 can advantageously be formed simultaneously in the process of forming the ceramic coating 7 on the first side A of the substrate 1. The thickness D2 of the ceramic coating 2 on the second side B of the substrate 1 can in particular be less than 135 nm, in particular in the range from 3 to 95 nm, preferably in the range from 15 nm to 45 nm.

As further shown in Fig. 2, the second embodiment of the laser weldable composite material V according to the invention likewise comprises a strip-shaped metal substrate 1 having a first side A with a ceramic coating 7. And the second side B. According to the invention, it is also designed here that the thickness D ₇ of the ceramic coating 7 on the first side A of the base body 1 falls within the range from 20 nm to 135 nm, and in the direction of the ceramic coating 7 A metal layer 8 having a thickness D ₈ of 5 nm to 25 nm is also present on the face of the substrate 1.

Furthermore, as with the first embodiment of the invention, there is also a ceramic coating 2 on the second side B of the base body 1, which in particular forms the intermediate layer 2, and above which the intermediate layer An optically effective multilayer system 3 is present on the second side B, although the multilayer system is formed only by at least two layers 4, 5.

The multi-layer system also relates to an upper layer 4 and a layer 5 mainly absorbing visible light under the upper layer, and the upper layer 4 may be an oxide layer, a fluorination layer, a vulcanized layer having a refractive index n<1.8, A nitride layer, an oxynitride layer and/or a carbon oxynitride layer, and the layer 5 forms the lowermost layer in this example. This layer 5 may in particular comprise a titanium-aluminum mixed oxide (Mischoxid) TiAl _q O _x and/or a titanium-aluminum mixed nitride (Mischnitrid) TiAl _q N _y and/or a titanium-aluminum mixed nitrogen oxide (Mischoxynitrid) TiAl _q O _x N _y , wherein the subscripts q, x and y represent stoichiometric or non-stoichiometric ratios, respectively, and are in the range of 0 < q and / or x and / or y < 3. Having the composite with such a layer, such as with the chromium-containing layer 5 according to the first embodiment of the invention, will make the composite particularly suitable for use in solar absorbers, which are distinguished by ease of manufacture and Has a high spectral selectivity.

In both embodiments, the metal layer 8 on the first face A of the substrate 1 and all the layers of the optical multilayer system 3 on the other substrate face B may preferably be sputtered layers, in particular by reactive sputtering. The formed layer, chemical vapor deposited layer (CVD layer) or plasma enhanced chemical vapor deposited layer (PECVD layer) or by evaporation, especially by bombardment with electrons or by heat source The resulting layer which is formed by evaporation is preferably formed in a continuous process and applied to the ceramic coatings 2, 7 in a vacuum state (Vakuumfolge). The application of the metallic titanium/chromium (Ti/Cr) layer 8 can be preferably achieved, for example, by using up to two flat magnetrons.

For the intermediate layer 2 which is also present between the substrate 1 and the optically effective multilayer system 3 in the second embodiment of the invention, it is particularly emphasized that when the intermediate layer 2 is placed on an aluminum substrate and made of alumina In time, then whether the underlying light absorbing layer 5 comprises titanium aluminum mixed oxide TiAl _q O _x and/or titanium aluminum mixed nitride TiAl _q N _y and/or titanium aluminum mixed nitrogen oxide TiAl _q O _x N _y , It is also important that the upper layer is an oxide layer of titanium, tantalum or tin having a chemical composition of TiOz, SiOw or SnOv, and the thickness D2 of the intermediate layer is not more than 30 nm. Here, it suffices that the upper layer only needs to have an insulating layer having a refractive index of less than 1.7. Of course, the refractive index of the upper layer can also be larger, for example, for the zinc oxide layer, it can be about 1.9, or for the titanium dioxide layer, it can be 2.55 (anatase) or 2.75 (rutile).

Surprisingly, when the intermediate layer 2 is made of alumina, and the aluminum oxide layer has only a very small thickness, that is, its thickness falls within a range of not more than 30 nm, particularly falling within a range of at least 3 nm, preferably When falling within the range of 15 nm to 25 nm, the intermediate layer not only functions to provide the substrate 1 with known mechanical protection and corrosion protection, but also ensures that the optical multilayer system 3 placed thereon is well bonded. And thus also the intermediate layer 2 and the substrate 1 itself are also optically effective. Thus, the intermediate layer 2 advantageously has a high transmission capacity, and the substrate 1 also has a high, due to the intermediate layer 2 The transmission becomes effective in the reflection ability, and thus the lowermost metal layer 6 of the optical multilayer system 3 of the first embodiment can be omitted without impairing the efficiency. In this way, on the one hand, the process steps for applying a layer are saved, and on the other hand, the material is saved, in particular the well-known precious metals such as gold and silver and the likewise cost-effective molybdenum which are preferably used for the lowermost metal layer are saved.

For example, the composite material V according to the invention can be produced using the above two embodiments of the optically effective multilayer system 3, in which the second side B of the substrate 1 is determined in accordance with DIN 5036 Part 3 The absorbance has a maximum in the wavelength range of about 300 to 2500 nm and the maximum is greater than 90%, and has a minimum in the wavelength range of more than 2500 nm and the minimum is less than 15%. On the second side B of the optical multilayer system 3, the total light reflectance determined in accordance with DIN 5036 Part 3 is less than 5%.

The graphs shown in Figures 3 and 4 reflect the relationship between the reflectivity R of the third and fourth embodiments of the laser weldable composite material V according to the present invention and the wavelength of the incident ray L, as a reference, Also shown is a relationship between the reflectance of a known comparative material not according to the present invention and the wavelength of incident light. In the figure, the curve RV represents the reflectance R of the composite material V according to the present invention, and Curve R0 represents the reflectance R of the comparative material.

A third embodiment of the composite material V according to the invention relates to a composite material in which a ceramic coating 7 having a composition of Al ₂ O ₃ and a thickness D ₇ of 95 nm is deposited on the first side A of the aluminum substrate 1 Further, a metal layer 8 having a composition of chromium and a thickness D ₈ of 10 nm is directly deposited on the ceramic coating 7. The fourth embodiment of the composite material V according to the invention relates to a composite material in which a ceramic coating having a composition of Al ₂ O ₃ and a thickness D ₇ of 40 nm is deposited on the first side A of the aluminum substrate 1. 7. A metal layer 8 having a composition of chromium and a thickness D ₈ of 20 nm is deposited directly on the ceramic coating 7. In the comparative material, a ceramic coating 7 having a composition of Al ₂ O ₃ and a thickness D ₇ of 95 nm was deposited on the first face A of the aluminum substrate 1.

As can be seen from the plotted diagram, the incident angle α of the incident ray L is determined as the angle α between the laser beam L and the vertical line made on the surface of the substrate 1, that is, the normal vector N. In each of the examples, the incident angle α of the laser beam L is 75°.

It can be seen that for the composite material V according to the invention shown in FIG. 3, when the wavelength λ of the laser beam L is 1064 nm, the total area determined on the first side A of the substrate 1 according to the third part of DIN 5036 The reflectance R is less than 50%, and especially about 40%. Under the same conditions, the reflectivity R of the comparative material is about 50% higher, about 90%. As shown in FIG. 3, the reflectance R of the composite material V according to the present invention varies between about 48% (at a wavelength of 500 nm) and 42% (at a wavelength of about 1200 nm) over the entire test range of the wavelength λ. Among them, when the wavelength λ is 1000 nm, the reflectance R reaches its minimum value, that is, 40%.

For the composite material V according to the invention shown in FIG. 4, the total reflectance R determined on the first side A of the substrate 1 according to the third part of DIN 5036 is the same when the wavelength λ of the laser beam is 1064 nm. Less than 50%, however, in the range of wavelength λ of 500 nm to 1200 nm, the total reflectance R of the composite material shown in Fig. 4 is on average about 5% to 8 higher than the total reflectance R of the composite material shown in Fig. 3. %.

Figure 5 shows the relationship between the reflectivity R of the third embodiment of the laser weldable composite material V according to the invention and the incident angle a of the incident laser beam L, the relationship shown in the figure is The wavelength λ is determined to be 1064 nm. Therefore, the value of the reflectance R identified by a circle in FIG. 5 is the same as the value identified in the same manner in FIG. When the angle α is varied in the range of 65° to 80°, the reflectance R continuously increases from about 30% up to about 40%. In terms of angular correlation, the experiment shown in Figure 4 shows the same characteristics, where the value of the reflectance R (as mentioned above) goes up by less than about 10%.

The invention is not limited to the described embodiments, but includes all manner and measures that have the same effect in the sense of the invention. For example, the ceramic coating of the intermediate layer 2 can also be made of other materials without using alumina. For a possible advantageous configuration and an ideal process method for the optical multilayer system 3 which is within the scope of the invention, which is involved in the composite material V according to the invention, the specific details of which can be fully referred to the patent application EP 1 217 394 B1, EP 1 217 315 B1, EP 2 239 086 A1, EP 2 336 811 and WO 2011/076448 A1.

Furthermore, the invention is not limited to the combination of features defined in claim 1, which may also be defined as any other combination of certain features from a single feature that has been fully disclosed. This means that, in principle and in practice, each individual feature recited in claim 1 can be deleted, or that each individual feature recited in claim 1 can be used elsewhere in this application. At least one individual feature disclosed is substituted. Especially for the layers present in the composite material according to the invention, The sequence illustrated (in the described sequence, the layers are directly adjacent to one another and made of the same material) does not exclude the possibility of continuing to provide additional intermediate layers, upper layers and/or layers in the layer system. The lower layer, or the layer and/or the sub-layer on the first side A of the substrate 1, in particular the metal layer 8 and the infrared reflecting layer 4 on the second side B of the substrate 1 and the layer 5 for absorbing visible light It is also constructed in multiple layers. In this regard, claim 1 can only be understood as an initial expression attempt for an invention.

1‧‧‧ base

2‧‧‧Intermediate layer on substrate 1, ceramic layer on face B

3‧‧‧Optically effective multi-layer system

4‧‧‧Infrared reflective layer of multi-layer system 3

5‧‧‧ Layers of multi-layer system 3 that absorb visible light

6‧‧‧Upper level of multi-layer system 3

7‧‧‧Ceramic layer on base 1 (face A)

8‧‧‧Metal layer on ceramic layer 7 (face A)

A‧‧‧ The first side of the substrate 1 (with ceramic layer 7, metal layer 8)

B‧‧‧ second side of the substrate 1 (with intermediate layer 2, multilayer system 3)

D‧‧‧ (total) thickness of composite material V

D ₁ ‧‧‧ Thickness of substrate 1

D ₂ ‧‧‧The thickness of the intermediate layer 2

D ₃ ‧‧‧ Thickness of multilayer system 3

D ₄ ‧‧‧ Thickness of infrared reflective layer 4

D ₅ ‧‧‧ Thickness of layer 5 for absorbing visible light

D ₆ ‧‧‧ thickness of upper layer 6

D ₇ ‧‧‧Thickness of ceramic layer 7

D ₈ ‧‧‧Thickness of metal layer 8

L‧‧‧Laser beam

N‧‧‧French vector of composite material V

R‧‧‧reflectance

R0‧‧‧Comparative material's reflectance R curve

Curve of reflectivity R of RV‧‧‧ composite material V

V‧‧‧Composite

Α‧‧‧射角

Λ‧‧‧wavelength

In the following, the invention will be explained in more detail by means of two embodiments shown in the figures. 1 is a schematic cross-sectional view of a first embodiment of a laser weldable composite material in accordance with the present invention; and FIG. 2 is a schematic cross-sectional view of a second embodiment of a laser weldable composite material in accordance with the present invention; The correlation between the reflectivity of the third embodiment of the laser weldable composite material according to the invention and the wavelength of the incident ray is shown, and a well-known (non-according to the invention) comparative material is also shown Correlation between the reflectivity and the incident ray as a reference; FIG. 4 shows the correlation between the reflectance of the fourth embodiment of the laser-weldable composite material according to the present invention and the wavelength of the incident ray, and Also shown is the correlation between the reflectance of a known (not according to the invention) comparative material and incident light as a reference; FIG. 5 shows the first of the laser weldable composite according to the present invention. The correlation between the reflectivity of the three embodiments and the incident angle of incident light.

Claims (24)

A laser weldable composite material (V), which is particularly suitable for solar collector elements, comprising a strip-shaped substrate made of a metal having high reflection properties for laser rays (1) The substrate has a first side (A) and a second side (B), wherein at least on the first side (A) there is a ceramic coating (7), characterized in that from the substrate 1) As seen, there is a metal layer (8) on the ceramic coating (7), and the thickness (D ₇ ) of the ceramic coating ( ₇ ) and the thickness (D ₈ ) of the metal layer Designed such that the first surface (A) of the substrate (1) is such that the wavelength (λ) of the incident laser beam (L) is 1064 nm and the incident angle (α) is in the range of 65° to 80°. The total reflectance (R) determined in accordance with DIN 5036 Part 3 is less than 60%. The composite material (V) according to claim 1 is characterized in that the thickness (D ₇ ) of the ceramic coating layer (7) on the first side (A) of the base body (1) falls between 20 nm and 135 nm. Within the range, it preferably falls within the range of 40 nm to 95 nm. The scope of patented composite material (V) to item 1 or 2, characterized in that the thickness of the metal layer (8) on (1) a first surface (A) of the base (D ₈₎ to fall within 5nm In the range of 25 nm, it preferably falls within the range of 10 nm to 20 nm, particularly preferably 15 nm. The composite material (V) according to claim 1 or 2, characterized in that the ceramic coating (7) on the first side (A) of the base body (1) is made of alumina. For example, the composite material (V) of claim 1 or 2, The matrix (1) of the composite material is made of aluminum. A composite material (V) according to claim 4, characterized in that the alumina of the ceramic coating (7) on the first side (A) of the substrate (1) is made of the substrate (1) Aluminum is anodized or electrolytically polished and anodized. The composite material (V) according to claim 1 or 2, characterized in that the metal layer (8) on the first side (A) of the base body (1) contains chromium and/or titanium or is completely composed of Made of materials. The scope of the patent or the two first composite material (V), characterized in that the thickness of the ceramic coating (7) ₍₇ D) and the metal layer (8) (D ₈₎ The size is designed such that the wavelength (λ) of the incident laser beam (L) is 1064 nm and the incident angle (α) is in the range of 65° to 80°, the first side of the substrate (1) (A) The total reflectance (R) determined according to DIN 5036 Part 3 is less than 50%, preferably less than 40%. The composite material (V) according to claim 1 or 2, characterized in that a ceramic coating (2) is present on the second side (B) of the substrate (1), the ceramic coating particularly forming the middle Layer (2). The composite material (V) according to claim 9 is characterized in that the ceramic coating (2) on the second side (B) of the base body (1) is used and located in the substrate (1) The ceramic coating (7) on the first side (A) is made in the same manner. A composite material (V) according to claim 1 or 2, characterized in that optical presence is present on the second side (B) of the base body (1) A multi-layer system (3) comprising at least two layers (4, 5), preferably comprising at least three layers (4, 5, 6). The composite material (V) according to claim 1 or 2, characterized in that the metal layer (8) and/or, if necessary, the optically effective multilayer system (3) is at least partially Applied to the ceramic coating (7, 2) by a continuous vacuum strip coating on the first side (A) of the substrate (1) and, if necessary It is located on the second side (B) of the substrate (1). The composite material (V) according to claim 11 is characterized in that the optically effective multilayer system (3) comprises two insulating and/or oxide layers (4, 5), namely an upper layer (4) and a layer (5) located below the upper layer and mainly for absorbing visible light, the upper layer (4) being an oxide layer, a fluorination layer, a vulcanization layer, a nitride layer, an oxynitride layer having a refractive index n<1.8 And / or carbon oxynitride layer. The composite material (V) according to claim 11 is characterized in that the optically effective multilayer system (3) comprises three layers (4, 5, 6), wherein one/the upper layer (4) Is an insulating layer and/or an oxide layer, one/the layer mainly absorbing visible light (5) forms a middle layer, and the lowermost layer (6) is a metal infrared reflective layer, and the lowermost layer is preferably gold or silver Made of copper, chrome, aluminum and/or molybdenum. The composite material (V) according to claim 14 is characterized in that the thickness (D ₆ ) of the lowermost layer ( ₆ ) falls within the range of 3 nm to 500 nm. The composite material (V) according to claim 13 is characterized in that the layer (5) which mainly functions to absorb visible light contains titanium aluminum mixed oxide TiAl _q O _x and/or titanium aluminum mixed nitride TiAl _q. N _y and/or titanium aluminum mixed oxynitride TiAl _q O _x N _y , wherein the subscripts q, x and y represent stoichiometric or non-stoichiometric ratios, respectively, and 0 < q and / or x and / or y < 3. The composite material (V) according to claim 13 is characterized in that the layer (5) mainly for absorbing visible light contains chromium oxide having a chemical composition of CrO _r and/or nitriding of a chemical component of CrN _s . The chromium and/or the chemical composition is CrO _r N _s chromium oxynitride, wherein the subscripts r and s represent stoichiometric or non-stoichiometric ratios, respectively, and 0 < r and / or s < 3. The scope of patented composite material (V) to item 13, wherein said upper layer (4) the chemical composition of the oxide layer is TiO _z, SiO _w or SnO _v titanium, silicon or tin, wherein the The indices v, w, and z represent stoichiometric or non-stoichiometric ratios in the oxidizing component, respectively, and 1 < v and / or w and / or z 2, preferably 1.9 v and / or w and / or z 2. The composite material (V) according to claim 9 is characterized in that the ceramic coating (2) on the second side (B) of the substrate (1) is made of the aluminum of the substrate (1) through the anode Oxidized or electrolytically polished and formed by anodization, and an intermediate layer (2) is formed underneath the optically effective multilayer system (3) of the substrate (1), the intermediate layer having a thickness (D ₂ ) which is especially smaller than 135 nm, preferably falling within the range of 3 to 95 nm, particularly preferably falling within the range of 15 nm to 45 nm, or especially less than 30 nm, preferably falling within the range of 15 to 25 nm. The composite material (V) according to claim 13 is characterized in that the thickness (D ₄ ) of the upper layer (4) of the optically effective multilayer system (3) falls within the range of 3 nm to 500 nm. The composite material (V) according to claim 13 is characterized in that the thickness (D ₅ ) of the layer (5) which mainly functions to absorb visible light of the optically effective multilayer system (3) falls within 0.01 μm to Within the range of 1.00 μm. The composite material (V) according to claim 13 is characterized in that the absorption rate determined on the second side (B) of the base body (1) according to the third part of DIN 5036 is in the wavelength range of about 300 to 2500 nm. There is a maximum within and the maximum is greater than 90%, and has a minimum in the wavelength range greater than 2500 nm and the minimum is less than 15%. The composite material (V) according to claim 13 is characterized in that the total light reflectance determined according to the third part of DIN 5036 on the second side (B) of the optical multilayer system (3) is less than 5%. A composite material (V) according to claim 1 or 2, characterized in that the composite material is constructed as a tape having a width of up to 1600 mm and a thickness falling within the range of about 0.1 mm to 1.5 mm. Within, it preferably falls within the range of 0.2 to 0.8 mm.