DE102007047014B4 - Process for producing a gas-tight and high-temperature-resistant connection of molded parts by means of laser - Google Patents

Abstract

Method for producing a gastight and high-temperature-resistant connection of a first molded part (1), wherein the first molded part (1) has at least one recess or through opening projecting into the molded part and is formed from a semi-transparent oxide ceramic, and at least one second molded part (2) wherein the second mold part (2) is formed from a material selected from the group consisting of oxide ceramics, non-oxide ceramics and / or metal, wherein the moldings (1, 2) by means of a glass solder and / or glass ceramic solder (3) connects by the zu connecting surfaces of the moldings (1, 2) with glass solder and / or glass ceramic solder (3) are provided and by laser irradiation, the temperature at the surfaces to be joined of the moldings (1, 2) is heated to the melting temperature of the solder or beyond by radiates through the semi-transparent oxide ceramic.

Description

State of the art

The present invention relates to a method for producing a gas-tight and high-temperature resistant connection of molded parts by means of laser.

Functional ceramics and high-temperature ceramics must often have gas-tight seals and joint seams according to their purpose. For example, the ZrO ₂ ceramic which is oxygen-conductive in the high-temperature range must frequently be connected to an insulating material, usually a further ceramic, which optionally has to be connected to a further metallic component.

The high-temperature-resistant joining of ceramic components is carried out according to the prior art often in complex furnace processes. Also, methods for joining ceramics to solders by laser are known in the art. Soldering processes using laser steel technology, however, are a new and under-researched field for ceramic components.

The disadvantage here is generally that caused by the limited to certain areas heating by the laser thermal stresses that can lead to damage to the ceramic by cracking. To avoid this, the components to be joined can be preheated to a temperature below the melting temperature of the solder.

Furthermore, the document discloses RU 2 099 312 C1 the preparation of a connection between a metallized aluminum oxide ceramic and a metal using a copper solder, wherein the solder seam is located inside the component. To heat the internal solder seam, a defocused pulsed laser is used.

A disadvantage of using metallic solders, however, is that the ceramic to be joined must first be metallized in order then to be able to be joined by means of the metallic solder. This includes a further process step, which is also associated with additional costs. In addition, the operating temperature and operating atmosphere is limited by the tendency of metallic solders to oxidize. Alternatively, in principle, non-metallized ceramics can be joined by means of metallic solders containing particularly reactive Lotbestandteile. However, in this so-called active soldering, the temperature and atmosphere of use are still further limited by the particularly reactive solder components.

Disclosure of the invention

The inventive method for producing a gas-tight and high-temperature resistant connection of molded parts by means of laser irradiation has the advantage over the prior that a preheating of the components is not required. Another advantage is that the high temperature resistance of the joined moldings can be improved.

This is inventively achieved by a method for producing a gas-tight and high-temperature resistant connection of a first molded part, wherein the first molded part has at least one protruding into the molding recess or a through hole and is formed of a semi-transparent oxide ceramic, and at least one second molded part, wherein the formed second molding is made of a material selected from the group consisting of oxide ceramic, non-oxide ceramic and / or metal, wherein connecting the moldings by means of a glass solder and / or glass ceramic solder by the surfaces to be joined of the moldings are provided with glass solder and / or glass ceramic solder and through Laser irradiation, the temperature is heated at the surfaces to be joined of the moldings to the melting temperature of the solder or beyond, by radiating through the semitransparent oxide ceramic.

Furthermore, it is possible by the inventive method to connect surfaces to be joined in the interior of moldings made of semitransparent oxide ceramic with another molding.

In particular, the targeted heating of an internal soldering seam by means of a laser has the great advantage that lower thermal stresses occur in the direction of the laser beam. Another advantage is that a uniform heating can be provided.

In addition, the inventive method allows a simpler and more cost-effective production of molded ceramic ceramics, which can be joined with a further metallic molding on a glass or glass ceramic solder without the oxide ceramic molding must be previously metallized.

The modular design of a component joined from several materials also has the advantage that those materials can be used at all points of the component, which are optimally suitable at the respective point from a structural or functional point of view.

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• 1 eine Anordnung eines Oxidkeramikformteils, wobei ein weiteres Formteil aus Keramik sowie ein Glaskeramiklot in dem Oxidkeramikformteil angeordnet sind.

The invention is based on the 1 explained in more detail. Hereby shows:

• 1 an arrangement of an oxide ceramic molding, wherein a further molded part made of ceramic and a glass ceramic solder are arranged in the oxide ceramic molding.

1 shows a molding 1 made of oxide ceramics, in which another molding 2 ceramic and a glass ceramic solder 3 are arranged. The arrangement of the molded parts is rotated, whereby the joining surfaces in the interior of the oxide ceramic molding 1 are exposed to medium radiation.

Preferred embodiments of the method according to the invention are claimed with the subordinate claims and are explained in more detail below.

The method for producing a gas-tight and high-temperature resistant connection of molded parts is preferably a joining method. For the purposes of the present invention, the term "joining" is to be understood as the permanent joining of at least two molded parts, in particular components. The compound of the moldings is preferably stationary, not detachable and / or material fit. The connection of the moldings is preferably stationary, not detachable and cohesive. Preference is given to thermal processes for bonded joining, in particular soldering processes, particularly preferred methods of laser beam soldering.

In the context of the present invention, the term "joint surface" is to be understood as meaning the surfaces of the molded parts to be joined, which enable the local cohesion of the molded parts after the connection has been established. In the context of the present invention, the term "joining zone" is to be understood as meaning the region of the molded parts comprising at least the surfaces of the molded parts to be joined and the intermediate space of the molded parts, wherein ceramic regions which are regularly adjacent to the joining surfaces are included. In the context of the present invention, the term "soldered seam" is to be understood as meaning the region of the molded parts comprising the connecting solder as well as at least the adjoining joining surfaces of the molded parts, wherein ceramic regions which are regularly adjacent to the joining surfaces are included.

The surfaces to be joined of the molded parts can be provided, for example, with glass solder and / or glass-ceramic solder, by arranging the glass solder and / or glass-ceramic solder within the recess or through opening.

Furthermore, the surfaces to be joined of the molded parts can be provided with glass solder and / or glass ceramic solder by the glass solder and / or glass ceramic solder is in a reservoir at the entrance of the access opening to the joining zone of the surfaces to be joined of the molded parts. In this case, by heating the joining zone, the glass solder and / or glass-ceramic solder will flow into the intermediate space of the two molded parts due to the action of the capillary forces.

In preferred embodiments of the method, a relative movement between the mold parts and at least one laser beam is performed by rotating or moving the mold parts, at least one movable laser beam and / or at least one movable laser. Moving is preferably a reciprocation.

A relative movement of moldings and laser beam can advantageously lead to a uniform heat input can be achieved. In particular, the relative movement of molded parts and laser beam can have the advantage that, compared to the temperature in the outer regions of the molded parts, an increase or maximization of the temperature in the interior of the semitransparent ceramic oxide molding can be achieved.

The to be joined in particular to be joined moldings can be arranged on or in each other, wherein the surfaces to be joined of the moldings are provided with glass solder and / or glass ceramic solder, in particular at least one to be joined surface of the first and / or second molded part are provided with the solder can. It may be advantageous that pressure is exerted on the arrangement of the molded parts in order to reinforce the cohesion of the molded parts to be joined. For example, the surfaces to be joined can be pressed against each other or pressed.

The method according to the invention can be used for a first molded part formed from a semi-transparent oxide ceramic. The term "semitransparent" in the sense of this invention means that the oxide ceramic is partially permeable, in particular for laser radiation. It is preferred that the semitransparent oxide ceramic for radiation having wavelengths in the range of 300 nm to 7 microns, preferably in the range of 300 nm to 5 microns, preferably in the range of 300 nm to 3 microns, more preferably in the range of 800 nm to 1100 nm, partially permeable. This makes it possible, for example, when using a laser with a corresponding wavelength heating inside and / or low-lying areas of the semitransparent oxide ceramic molding.

The energy input by the laser radiation is advantageously carried out by partial absorption of the radiation in the ceramic into the component interior.

In preferred embodiments, the semitransparent oxide ceramic has an absorption coefficient in the range of 2% / mm to 50% / mm, preferably in the range of 4% / mm to 40% / mm, preferably in the range of 5% / mm to 25% / mm , The term "absorption coefficient" in the context of the present invention has the meaning that, for example, per millimeter of the oxide ceramic 2% of the incident energy of the laser are absorbed by the oxide ceramic. The remaining radiation is not absorbed by the material and therefore not converted into heat.

The inventive method makes it possible to add even ceramics, which have a poor thermal conductivity and in which this easily build up thermal stresses due to temperature differences in the areas adjacent to the heated areas.

Preferred semitransparent oxide ceramics are oxide ceramics based on oxides or containing oxides selected from the group comprising zirconates, aluminates, silicates, titanates and / or mixtures thereof, in particular selected from the group comprising ZrO ₂ , Al ₂ O ₃ , MgAl ₂ O ₄ , SiO ₂ , Mg ₂ SiO ₄ , cordierite, mullite, TiO ₂ , Al ₂ TiO ₅ and / or mixtures thereof. Particularly preferred oxide ceramics are oxide ceramics based on ZrO ₂ . An advantage of these oxide ceramics is that they have suitable semitransparency, in particular for radiation having wavelengths in the range from 800 nm to 1100 nm. This makes it possible that transmission paths from the molding surface to the solder seam in a range of a few micrometers to centimeters can be achieved. In preferred embodiments, for example, radiation paths in the range of 1 mm to 30 mm can be achieved.

For the purposes of the present invention, the term "non-oxide ceramic" is understood to mean ceramics made from oxygen-free ceramic materials which consist predominantly or exclusively of non-oxidic substances, for example borides, carbides, nitrides or oxynitrides, in particular silicon nitride, silicon carbide, aluminum nitride or boron carbide.

The method according to the invention makes it possible to connect molded parts made of semitransparent oxide ceramics with molded parts made of materials selected from the group comprising oxide ceramics, non-oxide ceramics and / or metal. Moldings may be formed of oxide ceramics, non-oxide ceramics, metal or ceramic-metal compounds or composite materials. Suitable oxide-ceramic-metal composites are, for example, cermets. For the purposes of this invention, the term "cermet" is to be understood as meaning composites made of ceramic materials in a metallic matrix. Preferred ceramic components here are selected from the group consisting of aluminum oxide, Al ₂ O ₃ , and / or zirconium oxide, ZrO ₂ . Preferred metallic alloys contain metals selected from the group comprising niobium, molybdenum, titanium, iron, cobalt and / or chromium.

With the method according to the invention molded parts can be formed from the same or different ceramics with each other. Furthermore, molded parts can be formed formed of oxide ceramics with metallic moldings. Further molded parts can be formed formed of oxide ceramics with molded parts formed of non-oxide ceramics.

Preferred metals have an expansion coefficient in the range of 7 * 10 ^-6 / K to 15 * 10 ^-6 / K, preferably in the range of 7.5 * 10 ^-6 / K to 12 * 10 ^-6 / K, preferably in the range of 8.5 * 10 ^-6 / K to 10 * 10 ^-6 / K. Preferred metals are selected from the group comprising Cu, Ti, Fe, Ni, Co, Cr, Zr, W, Mo, Al, V, Si and / or their alloys and / or mixtures. Preferred metal alloys are aluminum-vanadium alloys. A particularly preferred metal alloy is available under the trade name Kovar®. This has for example a composition Ni 29%, Co 17%, Fe 54%.

An advantage of the preferred metal compounds results from the fact that it is possible to produce joint compounds with oxide ceramics based on ZrO ₂ , Al ₂ O ₃ and / or Mg ₂ SiO ₄ , which can provide sufficient mechanical stability. In particular, it is advantageous that in a combination of oxide ceramics with metals and metal compounds selected from the group comprising Cu, Ti, Fe, Ni, Co, Cr, Zr, W, Mo, Al, V, and / or Si in the preparation of Connections no or only small thermal stresses occur.

According to the method of the invention, glass solders and / or glass-ceramic solders are used. One advantage of glass and glass ceramic solders is that they can wet the ceramics well, in particular they can wet better than metal solders, while the wetting of metals is comparably good to that of metal solders. A particular advantage with the use of glass and / or glass ceramic solders is that oxide ceramic moldings are usable in contrast to the use of metallic solders without metallization of the ceramic surface. Another advantage of the glass and glass ceramic solders is that they are gas-tight and high temperature resistant.

For the purposes of this invention, the term "glass solder" is understood as meaning glass compositions which have no crystalline constituents, while "glass-ceramic solders" comprise crystalline constituents in the composition.

Useful compositions for glass and / or glass-ceramic solders are preferably based on silicate glass with additions of oxides of the elements of main group II, preferably selected from the group comprising MgO, CaO, SrO, and / or BaO, oxides of the elements of main group III, preferably selected from the group comprising B ₂ O ₃ and / or Al ₂ O ₃ , and / or oxides of the elements of the subgroups, preferably selected from the group comprising TiO ₂ , Fe ₂ O ₃ , FeO, ZnO, Y ₂ O ₃ , ZrO ₂ , and / or La ₂ O ₃ .

Particularly suitable glass and / or glass-ceramic solders, which are particularly useful for oxide ceramics based on alumina, for example, from the Scriptures DE 100 16 414 to which reference is hereby incorporated by reference.

Preferably usable glass and glass ceramic solders can be melted from a starting mixture containing SiO ₂ , Al ₂ O ₃ , TiO ₂ and CaO, wherein in addition to these constituents further glass components such as magnesium oxide, barium oxide, zirconium dioxide and / or iron oxide may be contained. Preferably, the proportion of silica in the range of 38 wt .-% to 48 wt .-%, the proportion of aluminum oxide in the range of 15 wt .-% to 19 wt.%, The proportion of titanium dioxide in the range of 4.5 wt % to 11% by weight and the proportion of calcium oxide in the range of from 23% to 30% by weight. Furthermore, the starting mixture may contain an alkali metal oxide, in particular lithium oxide, potassium oxide and or sodium oxide, preferably in an amount of up to 1.5% by weight, based on the total weight of the starting mixture. Preferably, zirconia may also be added to the starting mixture. A particularly preferred glass ceramic can be produced from a starting mixture which comprises 43% by weight to 48% by weight SiO ₂ , 16.5% by weight to 18% by weight Al ₂ O ₃ , 6% by weight to 10 , 5 wt .-% TiO ₂ , 0.3 wt .-% to 1.2 wt .-% Na ₂ O, 0.3 wt .-% to 1.2 wt.% K ₂ O and 24.5 wt .% to 28.5 wt .-% CaO.

Also preferably usable are glass-ceramic solders based on silicon dioxide, aluminum oxide and barium oxide. Further preferably usable glass-ceramic compositions comprise silica, alumina, barium oxide, calcium oxide and boron oxide. Further particularly preferably usable glass and / or glass ceramic compositions, which are particularly preferably used for oxide ceramics based on ZrO ₂ and Mg ₂ SiO ₄ are, for example, in the publications DE 600 25 364 T2 and DE 198 57 057 C1 which is incorporated herein by reference in its entirety. For glass oxide based on ZrO ₂ and Mg ₂ SiO ₄ preferably usable glass solders and glass ceramic solders are preferably free of alkali metal oxides.

Advantageously, the glass or glass ceramic solder can be applied in a solid form, preferably in powdery or pasty form, or in the form of a shaped body, for example a film or strip-shaped. Furthermore, the glass or glass ceramic solder can be used in the form of a coating. The solder can also be applied in the form of a suspension. The glass or glass ceramic solder is preferably usable in the form of a glass powder, a glass powder mixture, a glass ceramic powder and / or a glass ceramic powder mixture. It is also possible to introduce the solder in a recess or a groove of the joint. It is also possible to present the glass solder and / or glass-ceramic solder in a reservoir at the entrance of the access opening to the joining zone of the surfaces to be joined of the molded parts.

The temperature at the surfaces to be joined in particular to be joined is heated to a temperature corresponding to or above the melting temperature of the solder by means of laser irradiation. By heating to a temperature corresponding to or above the melting temperature of the solder, the connection formation between the first molded part and the second molded part occurs by means of the solder. The solder remains after making the connection between the moldings and forms a gas-tight and high temperature resistant connection between the moldings.

Preferred melting temperatures of the glass and / or glass ceramic solders are in the range from 700 ° C. to 1400 ° C., preferably in the range from 800 ° C. to 1300 ° C., preferably in the range from 900 ° C. to 1200 ° C.

By a temperature measuring device, such as a radiation pyrometer, the surface temperature of the oxide ceramic molding and the internal temperature can be determined. For example, via a temperature-dependent control of the laser power is a defined temperature in the range of the melting temperature of the usable solders adjustable.

During the heating by means of laser irradiation, a relative movement between the shaped parts and the laser beam is preferably carried out. This relative movement can be through Rotating or moving the moldings, at least one movable laser beam and / or at least one movable laser are performed, A moving is preferably a reciprocating.
For example, the molded parts can be rotated relative to a fixedly positioned laser. Furthermore, the at least one laser beam used can move in the plane of incidence of the molded part. In particularly preferred embodiments of the method, a relative movement between the mold parts, in particular components, and the laser beam is performed by the molding rotates, for example, a rotation about the z-direction in which the laser irradiates, performs, and the at least one laser beam in the Impact plane of the molding, for example, in the x, y plane is moved.

The molded parts can rotate, for example, in a suitable holder. The movement of the laser beam, in particular in the x, y plane, can be achieved by a suitable mirror device, for example a so-called scanner. In advantageous embodiments, the scanner can move at a speed in the range of 0 cm / s to 1.5 m / s, preferably in the range of 2 cm / s to 1.5 m / s, preferably in the range of 1 m / s to Move 1.5 m / s.

In other preferred embodiments, at least two or more movable laser beams may be used. The at least two movable laser beams may originate from a split beam or multiple laser sources. Two or more movable laser beams may strike at different locations on the molding surface. It is preferred that when two lasers are used, they are each movable in half spheres around the arrangement of the molded parts.

In preferred embodiments, the laser beam is moved end-point-free in the landing plane. A point-free movement of the laser beam has the advantage that no end point of a laser path, for example due to a short-term holding time of the laser beam and thus longer-term irradiation, is heated too much. Preferably, the movable laser beam is guided in the plane of incidence substantially circular, oval or elliptical. Such a movement advantageously leads to the fact that the movement of the laser beam has no end point, such as in a linear driving manner, in which a laser beam is guided back and forth.

The irradiation heats up the and / or the irradiated molded parts. By the relative movement of the molded parts and the laser beam can be advantageously achieved that the outer regions of the molded part, although temporarily heated stronger in direct irradiation, but can cool during the further circulation, since the laser beam does not irradiate the surface permanently in the same place. By a relative movement of the molded parts and the laser beam can be advantageously avoided that the surface is too hot and increased absorption occurs at the surface.

Oxide ceramics are in particular at wavelengths between 300 nm and 7 .mu.m, preferably in the range of 300 nm and 5 .mu.m, in particular in the range of 800 nm to 1100 nm partially transparent to radiation of this wavelength and can absorb this radiation. The energy input by the laser irradiation takes place by a partial absorption in the oxide ceramic into the molding interior. This allows heating of the molded part interior when using a laser emitting radiation of a suitable wavelength. The laser beam, which is directed onto the surface of the molded part, can thus achieve heating by irradiation into the molded part into the interior.

By the relative movement of the mold parts and the laser beam can be advantageously achieved that the maximum temperature entry takes place in the interior of the molded part. Bonding points inside the semi-transparent oxide ceramic molding are preferably subjected to medium irradiation, while the surface and outer regions are allowed to cool during rotation.

The temperature of the heated molded part thus advantageously increases from the inside to the outside. Advantageously, thermally induced stresses in this direction can be avoided by the heat energy gradient generated parallel to the irradiated laser beam.

Without wishing to be bound by any particular theory, it is assumed that the optical properties, in particular absorption or reflection of the oxide ceramic molding, change with its temperature. Thus, it is assumed that areas of the oxide ceramic, which have already absorbed more radiation, subsequently have a greater absorption, which favors the temperature increase in more remote areas. This can advantageously lead to the location of a temperature gradient moving from the molded part interior towards the surface during the laser irradiation. This can advantageously shade the interior of the molded part from further laser irradiation.

It is of particular advantage that the shading of the interior of the molding can lead to overheating of the molding can be avoided.

The temperature profile on the surface and in the interior of the molding is advantageously controllable by adjustable laser travel paths and / or rotational speeds.

In advantageous embodiments, the transmission path from the surface to the soldered seam of the molded part can be up to 30 mm.

With the method according to the invention rotationally symmetric as well as non-rotationally symmetrical shaped parts can be joined. For joining rotationally symmetrical shaped parts, in particular components, a relative movement between the molded part and the laser beam is preferred by rotation of the molded parts. When using non-rotationally symmetrical molded parts, the relative movement between the molded parts and the laser beam is preferably preferred by using at least two movable laser beams.

In preferred embodiments, the moldings are rotated at a speed of rotation in the range of 1 to 120 revolutions per minute, preferably in the range of 10 to 100 revolutions per minute, more preferably in the range of 50 to 80 revolutions per minute. This can offer the advantage that an increased energy input can be introduced into the interior of the molded part.

Pulsed or continuous laser radiation can be used. Preferably, continuous laser radiation is used. The use of continuous laser radiation can provide the advantage of continuous temperature input. Another advantage of using continuous laser radiation is that instantaneous excessive heating of the molded part, which can lead to thermal shock, can be reduced or even prevented.

It is possible to use focused, defocused, unshaped, directly or optically shaped laser radiation. For example, defocused laser radiation can provide the advantage of a broader energy distribution.

Particularly preferably usable lasers are selected from the group comprising diode laser and / or Nd: YAG laser.

After the connection has been formed, the joined moldings can cool freely or be cooled in a defined manner. Preferably, the bonded moldings may be cooled slowly or gradually. This can help to prevent damage to the ceramic moldings.

With the method according to the invention are joined moldings, in particular components, can be produced, which can meet high requirements for high temperature resistance, gas tightness and corrosion resistance.

embodiment

The invention will be explained in more detail with reference to the following embodiment, which describes the method according to the invention for a specific embodiment.

A solid rod of ZrO ₂ with the dimensions: diameter = 4 mm and length = 40 mm and a perforated disc of a semitransparent forsterithaltigen oxide ceramic with dimensions: outer diameter = 15 mm, inner diameter = 4.2 mm and thickness = 5 mm were by means of the invention Procedure added.

Solid rod and perforated disc were inserted into each other and used in a Rotationshalferung. In a chamfer with a radius of 1.5 mm, which was attached on one side to the inner diameter of the perforated disc, a solder plate made of sintered glass powder consisting of 61.75% by mass Y ₂ O ₃ , 33.25% by mass Al ₂ O ₃ and 5 Ma .-% SiO ₂ inserted in ring form. Now the laser beam of a diode laser of 808 nm and 940 nm wavelength and an approximately Gaussian beam with a diameter of 12-15 mm with an incident power of 1100 W was directed onto the joining seam. The beam was deflected in the x or y direction ± 5 mm with a scan speed of 1000 mm / s. This resulted in a temperature of 1100 ° C at the joint seam. The ceramic body was rotated during the laser processing at a speed of 25 revolutions per minute. After 90 seconds, the solder was completely melted.

The parts to be joined were permanently and gas-tight after cooling.

Claims (11)

Method for producing a gastight and high-temperature-resistant connection of a first molded part (1), wherein the first molded part (1) has at least one recess or through opening projecting into the molded part and is formed from a semi-transparent oxide ceramic, and at least one second molded part (2) wherein the second mold part (2) is formed from a material selected from the group consisting of oxide ceramics, non-oxide ceramics and / or metal, wherein the moldings (1, 2) by means of a glass solder and / or glass ceramic solder (3) connects by the zu connecting surfaces of the moldings (1, 2) with glass solder and / or glass ceramic solder (3) are provided and by laser irradiation, the temperature at the surfaces to be joined of the mold parts (1, 2) the melting temperature of the solder or more is heated by radiating through the semi-transparent oxide ceramic. Method according to Claim 1 , characterized in that the surfaces to be joined of the mold parts (1, 2) with glass solder and / or glass ceramic solder (3) are provided by the glass solder and / or glass ceramic solder (3) is disposed within the recess or through opening or the glass solder and / or glass-ceramic solder (3) in a reservoir at the entrance of the access opening to the joining zone of the surfaces to be joined of the molded parts (1, 2), wherein by heating the joining zone, the glass solder and / or glass ceramic solder (3) by the action of the capillary forces in the intermediate space of the two mold parts (1, 2) flows into it. Method according to Claim 1 or 2 , characterized in that one carries out a relative movement between the mold parts (1, 2) and at least one laser beam by rotating or moving the mold parts (1, 2), at least one movable laser beam and / or at least one movable laser. Method according to one of the preceding claims, characterized in that the semitransparent oxide ceramic for radiation having wavelengths in the range of 300 nm to 7 microns, preferably in the range of 300 nm to 5 microns, preferably in the range of 300 nm to 3 microns, more preferably in Range of 800 nm to 1100 nm, partially transmissive. Method according to one of the preceding claims, characterized in that the semitransparent oxide ceramic, an oxide ceramic based on oxides or containing oxides selected from the group comprising zirconates, aluminates, silicates, titanates and / or mixtures thereof, in particular selected from the group comprising ZrO ₂ , Al ₂ O ₃ , MgAl ₂ O ₄ , SiO ₂ , Mg ₂ SiO ₄ , cordierite, mullite, TiO ₂ , Al ₂ TiO ₅ and / or mixtures thereof. Method according to one of the preceding claims, characterized in that the metal has a thermal expansion coefficient in the range of 7 * 10 ^-6 / K to 15 * 10 ^-6 / K, preferably in the range of 7.5 * 10 ^-6 / K to 12 * 10 ^-6 / K, preferably in the range of 8.5 * 10 ^-6 / K to 10 * 10 ^-6 / K, wherein the metal is preferably selected from the group comprising Cu, Ti, Fe, Ni, Co, Cr, Zr, W, Mo, Al, V, Si and / or their alloys and / or mixtures. Method according to one of the preceding claims, characterized in that the melting temperature of the solder in the range of 700 ° C to 1400 ° C, preferably in the range of 800 ° C to 1300 ° C, preferably in the range of 900 ° C to 1200 ° C, lies. Method according to one of the preceding claims, characterized in that one carries the at least one movable laser beam in the landing plane endpunktfrei and / or substantially circular, oval or elliptical. Method according to one of the preceding claims, characterized in that one uses continuous laser radiation. Method according to one of the preceding claims, characterized in that the molded parts (1, 2) at a rotational speed in the range of 1 to 120 revolutions per minute, preferably in the range of 10 to 100 revolutions per minute, preferably in the range of 50 to 80 Revolutions per minute, rotates. Method according to one of the preceding claims, characterized in that one uses a laser selected from the group comprising diode laser and / or Nd: YAG laser.

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