Component, in particular wear-prone part, for arc burner, in particular for plasma burner or plasma cutting burner, arc burner having such component, and method for plasma cutting

Abstract

The invention relates to a component for an arc burner operating in an energized manner, in particular for a plasma burner or a plasma cutting burner, characterized in that the component or at least part or at least one region of the component is made of a material, the material comprises aluminum oxide and at least one of chemical elements silver and copper.

Description

Technical Field

[0001] The invention relates to a component for an arc burner, in particular a plasma burner or a plasma cutting burner, such as a holder or a receiving member for wearable parts and wearable parts such as an electrode, a nozzle, a nozzle cap and a nozzle guard; an arc burner, in particular a plasma burner or a plasma cutting burner, having such a component; and a method for plasma cutting. Background Art

[0002] Arc burners, in particular plasma burners (plasma arc burners), are generally used for thermal processing of different types of materials, for example metallic and non-metallic materials, for example in order to cut, weld, engrave or generally heat them.

[0003] For example, a TIG burner is an arc burner. It does not have a nozzle like a plasma burner. Nevertheless, the electrodes of an arc burner and a plasma burner can be designed to be the same.

[0004] Plasma burners usually consist essentially of a torch body, an electrode, a nozzle and a holder for these. Modern plasma burners additionally have a nozzle shroud mounted above the nozzle. The nozzle is often fixed by means of a nozzle cap.

[0005] Components that are subject to wear during operation of a plasma burner due to the high thermal load caused by the electric arc include, depending on the type of plasma burner, in particular the electrode, the nozzle cap, the nozzle guard, the nozzle guard holder and the plasma gas guide and the secondary gas guide. These components can be easily replaced by the operator and are therefore referred to as wear parts (components with a limited service life).

[0006] The plasma burner is connected to a power supply and a gas supply for supplying the plasma burner through a pipeline. In addition, the plasma burner can be connected to a cooling device for obtaining a cooling medium, such as a cooling liquid.

[0007] In particular, high thermal loads occur on plasma cutting burners. The reason for this is the strong converging of the plasma beam caused by the nozzle hole. Small holes are used here to generate 50 to 150 A / mm 2 High current density, about 2×106W / cm 2 The high energy density and high temperature up to 30000K are used in plasma cutting. In addition, a higher gas pressure is used in the plasma pattern, which is usually within 12bar. The high temperature and high kinetic energy of the plasma gas flowing through the nozzle hole combine to melt the workpiece and remove the melt. The cutting seam is formed and the workpiece is cut. In plasma cutting, oxidizing gases are often used to cut non-alloy steel or low-alloy steel, while non-oxidizing gases are used to cut high-alloy steel or non-ferrous metals.

[0008] The plasma gas flows between the electrode and the nozzle. The plasma gas is guided by the gas guide. This allows the plasma to be aligned in a targeted manner. Typically, a rotation around the electrode is caused by a radial offset and / or an axial offset of the opening in the plasma gas guide. The plasma gas guide is made of an electrically insulating material because the electrode and the nozzle must be electrically insulated from each other. This is necessary because the electrode and the nozzle have different electrical potentials when the plasma cutting burner is in operation. In order to operate the plasma cutting burner, an arc is generated between the electrode and the nozzle and / or between the electrode and the workpiece to ionize the plasma gas. In order to ignite the arc, a high voltage can be applied between the electrode and the nozzle, which causes the gap segment between the electrode and the nozzle to be pre-ionized and thereby forms an arc. The arc burning between the electrode and the nozzle is also called a pilot arc.

[0009] The pilot arc is ejected from the nozzle hole and hits the workpiece, and ionizes the gap section to the workpiece. As a result, an arc is formed between the electrode and the workpiece. This arc is also called the main arc. During the existence of the main arc, the pilot arc can be cut off. However, the pilot arc can also be maintained. During plasma cutting, the pilot arc is usually cut off to avoid additional load on the nozzle.

[0010] The electrodes and the nozzles in particular are subject to high thermal loads and must therefore be cooled. At the same time, they must also conduct the current required to form the arc. For this purpose, materials with good thermal and electrical conductivity are therefore used, generally metals such as copper, silver, aluminum, tin, zinc, iron or alloys containing at least one of these metals.

[0011] The electrode usually consists of an electrode holder and an emission insert, which is made of a material with a high melting point (>2000° C.) and a lower electron work function than the electrode holder. When using non-oxidizing plasma gases, such as argon, hydrogen, nitrogen, helium or mixtures thereof, tungsten is used as the material for the emission insert, and when using oxidizing gases, such as oxygen, air and mixtures thereof, nitrogen-oxygen mixtures and mixtures with other gases, hafnium or zirconium is used as the material for the emission insert. The high-temperature material can be pressed into the electrode holder made of a material with good thermal and electrical conductivity, for example by form fit and / or force fit.

[0012] The cooling of the electrode and the nozzle can be carried out by a gas, such as a plasma gas or a secondary gas, flowing along the outside of the nozzle. However, it is more effective to use a liquid, such as water, for cooling. The electrode and / or the nozzle are often directly cooled by the liquid, which means that the liquid is in direct contact with the electrode and / or the nozzle. In order to guide the cooling liquid around the nozzle, a nozzle cap surrounds the nozzle, and the inner surface of the nozzle cap and the outer surface of the nozzle form a coolant space in which the coolant flows.

[0013] In modern plasma cutting burners, there is additionally a nozzle shroud located outside the nozzle and / or the nozzle cap. The inner surface of the nozzle shroud and the outer surface of the nozzle or the outer surface of the nozzle cap form a space through which a secondary gas or a shielding gas flows. The secondary gas or the shielding gas is ejected from the holes in the nozzle shroud, envelops the plasma beam and is responsible for providing a defined atmosphere around the plasma beam. The secondary gas additionally protects the nozzle and the nozzle shroud from arcs that may form between the nozzle shroud and the workpiece. These arcs are called double arcs and may cause damage to the nozzle. In particular, when penetrating the workpiece, the nozzle and the nozzle shroud are exposed to a large amount of hot splashed material. The secondary gas protects the nozzle and the nozzle shroud from the splashed material and from damage, and during penetration the volume flow of the secondary gas can be increased compared to the value during cutting.

[0014] The nozzle guard is also subject to high thermal loads and must therefore be cooled. For this purpose, a material with good thermal and electrical conductivity is used, which is generally a metal, such as copper, silver, aluminum, tin, zinc, iron or an alloy containing at least one of the above metals.

[0015] The electrodes and nozzles can also be cooled indirectly. Here, the electrodes and nozzles come into contact with a component made of a material with good thermal and electrical conductivity (generally a metal, such as copper, silver, aluminum, tin, zinc, iron or an alloy containing at least one of the above metals) by contact. The component is in turn cooled directly, i.e. it is in direct contact with a coolant, which is usually fluid. These components can simultaneously serve as holders or receptacles for the electrodes, nozzles, electrode caps or electrode shields and remove heat and feed in current.

[0016] There is also the possibility of cooling only the electrodes or only the nozzles with liquid.

[0017] The nozzle shroud is usually cooled by the secondary gas. Assemblies are also known which cool the secondary gas cover directly or indirectly by means of a cooling liquid.

[0018] In plasma burners, especially plasma cutting burners, the high energy density and high temperatures result in high loads on the wear parts. This applies in particular to the electrode, the nozzle and the nozzle guard.

[0019] The currently known solution for electrodes is to embed an emitter insert made of a high melting point material, such as tungsten or hafnium, into a material with good thermal conductivity, such as copper or aluminum, but these solutions often do not achieve sufficient results. Especially under large currents, such as currents greater than 300A and when using oxygen-containing gases or gas mixtures as plasma gases, the life span is often too short. In addition, there are often large fluctuations in the life span. The emitter insert is worn during operation, that is, when the arc or plasma beam burns. Gradually, the emitter insert is back-burned. If the back-burning exceeds 1 mm, when copper is used as the electrode holder material, the entire electrode often fails suddenly. The arc or plasma beam is transferred from the emitter insert to the holder and destroys the holder. In this case, the nozzle is also damaged. It is even possible that the entire burner is destroyed.

[0020] When copper is used as the electrode holder material, the electrode burns back by a maximum of 1 mm before failure.

[0021] When silver is used as the electrode holder material, the electrode tends to burn back to 1.5 mm before failure.

[0022] Since this failure also occurs suddenly, it would lead to an abrupt end to the cutting process in the described situation. The material to be cut would then be unusable.

[0023] In particular, when using an oxygen-rich secondary gas, ie oxygen accounts for at least 25 volume percent of the secondary gas, an arc may form which burns between the nozzle, the shroud and the workpiece, a so-called double arc.

[0024] Oxygen-rich secondary gases have a positive effect on the cutting quality of the workpiece to be cut, especially when cutting structural steel, with fewer burrs and smoother cut surfaces. Compared to secondary gases without oxygen or with a low oxygen content, higher cutting speeds can often be used.

[0025] In particular, when using a secondary gas rich in argon, ie argon accounts for at least 25 volume percent of the secondary gas, an arc may form which burns between the nozzle, the shield and the workpiece, a so-called double arc.

[0026] A secondary gas enriched with argon has a positive effect on the cutting quality of the workpiece to be cut, in particular when cutting high-alloy steels, since the oxygen present in the ambient gas is kept away from the cut edge and reactions of this gas with the hot plasma-cut surface of the workpiece, such as oxidation reactions, are avoided.

[0027] The double arcing described may result in damage to the nozzle, nozzle cap and nozzle guard. Summary of the invention

[0028] The object of the present invention is to improve the life of components (such as holders and receptacles for wear parts) and wear parts (such as electrodes, nozzles, nozzle caps, nozzle guards) of arc burners (especially plasma burners or plasma cutting burners).

[0029] According to the invention, this object is achieved according to a first aspect by a component for an arc burner, which is operated in an energized manner, the component being particularly used for a plasma burner or a plasma cutting burner, characterized in that the component or at least a part or at least a region of the component is made of a material comprising aluminum oxide and at least one of the chemical elements silver and copper.

[0030] Furthermore, the object is achieved by an arc burner having at least one component according to any one of claims 1 to 23 .

[0031] Furthermore, the object is achieved by a plasma cutting method using an arc burner, wherein the plasma cutting burner is operated using oxygen, an oxygen-containing gas or a gas mixture, and / or a reducing gas or a gas mixture, and / or an inert gas or an inert gas mixture as plasma gas (PG) and / or secondary gas (SG).

[0032] Furthermore, the object is achieved by a plasma cutting method using an arc burner, wherein the plasma cutting burner is operated using oxygen or an oxygen-containing gas mixture as plasma gas (PG) and / or secondary gas (SG), wherein the oxygen in the oxygen-containing gas mixture accounts for at least 25% by volume of the gas mixture.

[0033] Furthermore, the object is achieved by a plasma cutting method using a plasma cutting burner, wherein the plasma cutting burner is operated using argon or a gas mixture containing argon as plasma gas (PG) and / or secondary gas (SG), wherein argon accounts for at least 25 volume percent of the gas mixture.

[0034] With regard to the components, provision can be made for at least one component or at least one of the components to be cooled with a liquid medium.

[0035] Alternatively, it may be provided that the proportion of aluminum oxide in the material mass or volume is at least 0.15%, preferably at least 0.3%, and most preferably at least 0.5%.

[0036] Suitably, the proportion of alumina in the volume or mass of the material is at most 2.0%, preferably at most 1.5%, most preferably at most 1.0%.

[0037] In a special embodiment, the component is a wearing part of an arc burner.

[0038] In particular, the wearable part may be an electrode for an arc burner.

[0039] According to another particular embodiment, the electrode has a front end and a rear end, extends along a longitudinal axis M and has at least one emission insert at the front end and an electrode holder and, if necessary, a holding element for the emission insert.

[0040] In particular, provision can be made here for at least a section of the inner surface of the electrode holder or of the holding element to be produced from the material, wherein the inner surface of the electrode holder or of the holding element is in direct contact with the emission insert.

[0041] Furthermore, it can be provided that the material extends radially outwards at least by 0.5 mm, preferably by at least 1 mm, and most preferably by at least 1.3 mm, starting from a section of the inner surface of the electrode holder or from a section of the inner surface of the holding element.

[0042] Advantageously, at least one section of the front face directly adjoining the front face of the emission insert comprises the material.

[0043] In particular, provision can be made here for the section of the front face to extend radially outwards by at least 0.5 mm, preferably by at least 1 mm, and most preferably by at least 1.3 mm.

[0044] Advantageously, the emitter insert consists of at least 90% by volume or mass of hafnium or zirconium or tungsten.

[0045] In another special embodiment, it can be provided that the wearing part is a nozzle having at least one nozzle opening.

[0046] In particular, it can be provided that at least a section of the inner surface of the nozzle opening comprises the material.

[0047] Advantageously, the material extends radially outwards by at least 0.5 mm, more preferably by at least 1 mm and most preferably by at least 1.3 mm, starting from at least a section of the inner surface of the nozzle opening.

[0048] According to another special embodiment of the invention, it can be provided that the wear part is a nozzle guard having at least one nozzle guard opening.

[0049] Advantageously, at least a section of the inner surface of the nozzle shroud opening comprises said material.

[0050] Advantageously, the material extends radially outwards by at least 0.5 mm, more preferably by at least 1 mm, and most preferably by at least 1.3 mm, starting from at least a section of the inner surface of the nozzle shroud opening.

[0051] According to another special embodiment, it can be provided that the wearing part is a nozzle cap having at least one nozzle cap opening.

[0052] Preferably, at least a section of the inner surface of the nozzle cap opening comprises said material.

[0053] In particular, it can be provided that the material extends radially outwards by at least 0.5 mm, preferably by at least 1 mm and most preferably by at least 1.3 mm, starting from at least a section of the inner surface of the nozzle cap.

[0054] According to another special embodiment, it can be provided that the component is a receptacle or a holder for at least one wearing part of the arc burner.

[0055] In particular, it can be provided that the receptacle or the retaining element is a nozzle receptacle, a nozzle cap receptacle or an electrode receptacle or a nozzle guard receptacle.

[0056] According to a particular embodiment, the arc burner can be a plasma burner or a plasma cutting burner.

[0057] Finally, the method may provide for cooling the at least one component or at least one of the components with a liquid medium. The invention allows the life of components of arc burners, plasma burners and plasma cutting burners, for example the life of wear parts, in particular the life of electrodes, to be extended. The emitter insert can be further ablated back to more than about 2 mm without damaging the electrode.

[0058] In particular, the life of the electrode, the nozzle and the nozzle guard as well as their holders are extended.

[0059] The influence of double arcs is reduced by the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Further features and advantages of the invention are derived from the appended claims and the following description of a number of embodiments with reference to the accompanying schematic drawings, in which:

[0061] Figure 1 A cross-sectional view of a plasma burner according to a particular embodiment of the present invention is shown;

[0062] Figure 2 According to a particular embodiment of the present invention, Figure 1 A cross-sectional view of an electrode of a plasma burner;

[0063] Figure 2.1 Shows Figure 2 A front view of an electrode;

[0064] Figure 2.2According to a particular embodiment of the present invention, Figure 2 a cross-sectional view of an electrode holder of an electrode;

[0065] Figure 2.3 Shows Figure 1 Another cross-sectional view of an electrode of a plasma burner;

[0066] Figure 2.4 According to a particular embodiment of the present invention, Figure 2 A cross-sectional view of an emission insert of an electrode;

[0067] Figure 3 shows a cross-sectional view of an electrode according to another specific embodiment of the present invention;

[0068] Figure 3.1 Shows Figure 3 A front view of an electrode;

[0069] Figure 3.2 According to a particular embodiment of the present invention, Figure 3 a cross-sectional view of an electrode holder of an electrode;

[0070] Figure 3.3 According to a particular embodiment of the present invention, Figure 3 A front view of a holding element of an electrode;

[0071] Figure 3.4 Shows Figure 3.3 A side view of a retaining element;

[0072] Figure 4 shows a cross-sectional view of an electrode according to another specific embodiment of the present invention;

[0073] Figure 4.1 Shows Figure 4 A front view of an electrode;

[0074] Figure 4.2 According to a particular embodiment of the present invention, Figure 4 a cross-sectional view of an electrode holder of an electrode;

[0075] Figure 4.3 According to a particular embodiment of the present invention, Figure 4 A cross-sectional view of a holding element of an electrode;

[0076] Figure 5 shows a cross-sectional view of an electrode according to another specific embodiment of the present invention;

[0077] Figure 5.1 Shows Figure 5 A front view of an electrode;

[0078] Figure 5.2 According to a particular embodiment of the present invention, Figure 5 a cross-sectional view of an electrode holder of an electrode;

[0079] Figure 5.3 According to a particular embodiment of the present invention, Figure 5 A cross-sectional view of a holding element of an electrode;

[0080] Figure 6 shows a cross-sectional view of a nozzle according to a particular embodiment of the present invention;

[0081] Figure 6.1 Shows Figure 6 Another cross-sectional view of the nozzle;

[0082] Figure 7 shows a cross-sectional view of a nozzle guard according to a particular embodiment of the present invention;

[0083] Figure 7.1 Shows Figure 7 A cross-sectional view of a nozzle guard;

[0084] Figure 8 According to a particular embodiment of the present invention, Figure 1 A cross-sectional view of a nozzle cap of a plasma burner; and

[0085] Figure 8.1 A nozzle cap insert according to a particular embodiment of the invention is shown. Figure 8 Cross-sectional view of the nozzle cap. DETAILED DESCRIPTION

[0086] Figure 1 The cross-sectional view of a plasma cutting burner 1 according to a special embodiment of the present invention is shown, which has a nozzle cap 2, a plasma gas guide 3, a nozzle 4 with a nozzle opening 4.1 according to a special embodiment of the present invention, a nozzle receiving part and a nozzle cap receiving part 5, an electrode receiving part 6 and an electrode 7 according to a special embodiment of the present invention. The electrode 7 comprises an electrode holder 7.1 and an emission insert 7.3 with a length L1 (for example 3 mm), which has an outer peripheral surface 7.3.2 and a front end surface 7.3.1 (see Figure 2.4 ). The nozzle accommodating part and the nozzle cap accommodating part 5 are used as the holders of the nozzle and the nozzle cap in this example. However, in other examples, there may also be separate nozzle accommodating parts and nozzle cap accommodating parts.

[0087] The plasma cutting burner 1 further comprises a nozzle shroud receptacle 8, to which a nozzle shroud 9 according to a special embodiment of the invention having a nozzle shroud opening 9.1 is fastened. In this example, the plasma cutting burner 1 also comprises a secondary gas guide 10. The secondary gas SG is supplied via the secondary gas guide 10. In addition, a plasma gas supply, coolant circuits WR1 and WR2, and coolant inlets WV1 and WV2 are present on the plasma cutting burner 1. During operation, the arc or plasma beam burns between the emission insert 7.3 of the electrode 7, flows through the nozzle opening 4.1 and the nozzle cap opening 9.1 and is thereby converged, and then strikes the workpiece (not shown). The inner surface of the nozzle opening 4.1 is designated as 4.2, and the inner surface of the nozzle cap opening 9.1 is designated as 9.2.

[0088] Figure 2 and Figure 2.1 Shows Figure 1 The electrode 7, wherein Figure 2 is a cross-sectional view through electrode 7. Figure 2.1 is a view A facing the front end of the electrode 7. The electrode 7 has a front end 7.1.8 including a front face 7.1.1, a rear end 7.1.9, an outer surface 7.1.2 and a cavity 7.1.1 through which a coolant flows or can flow in the installed state. The electrode 7 comprises Figure 2.2 The electrode holder 7.1 and Figure 2.4 7.3 is shown by way of example in FIG. The emission insert 7.3 is pressed into a hole 7.1.5 of the electrode holder 7.1 with a diameter D1 (e.g. 1.8 mm (-0.05)). The hole 7.1.5 has an inner surface 7.1.3 in direct contact with an outer peripheral surface 7.3.2 of the emission insert 7.3. The body of the emission insert 7.3 in this example preferably consists of at least 97% hafnium, the remainder being essentially zirconium.

[0089] The electrode holder 7.1 is made of a material composed of silver, copper and aluminum oxide Al2O3, for example. The distribution of the mass ratio is, for example, as follows: 92.5% silver, 7% copper and 0.5% aluminum oxide Al2O3. Among them, this material is used for the entire electrode holder 7.1, for example. There is also the possibility that this material is present only in a part or an area of ​​the electrode holder 7.1. Then preferably, this is the case at least on the inner surface 7.1.3 of the electrode holder 7.1. The area preferably extends radially outwards by at least 0.5 mm from the inner surface. It is better that the area extends radially outwards by at least 1 mm. This can be achieved, for example, in the following way, that the aluminum oxide ratio and / or the silver ratio decreases radially outwards, while the copper ratio increases.

[0090] In the cross-sectional view showing the electrode 7 Figure 2.3In FIG. 1 , the tempering ablation length L2 is also shown. The tempering ablation length is defined as the distance between the surface 7.3.1 of the emission insert 7.3 in the new state and the deepest point of the surface ablated by tempering during operation. In the present example, for example, L2=2 mm.

[0091] It is also possible to produce the electrode holder from only one material consisting of copper and aluminum oxide, for example, with a mass fraction of 99.5% copper and 0.5% aluminum oxide being given.

[0092] Figure 3 An electrode 7 according to another particular embodiment of the present invention is shown, wherein Figure 3 is a cross-sectional view through electrode 7, Figure 3.1 is a view A facing the front end 7.1.8 of the electrode 7. The electrode 7 has a front end 7.1.8 including a front face 7.1.1, a rear end 7.1.9, an outer surface 7.1.2 and a cavity 7.1.1 through which a coolant flows or can flow in the installed state. The electrode 7 comprises Figure 3.1 The electrode holder 7.1 shown in the example, Figure 3.3 and Figure 3.4 2 and the emission insert 7.3 are shown by way of example in FIG. The emission insert 7.3 is pressed into a hole 7.2.1 of the holding element 7.2, the diameter of which is D5. The hole 7.2.1 has an inner surface 7.2.3, which is in direct contact with the outer circumferential surface 7.3.2 of the emission insert 7.3.

[0093] The holding element 7.2 with an outer diameter D3 is pressed into a hole 7.1.5 of the electrode holder 7.1, which has an inner diameter D1. The hole has an inner surface 7.1.3 which is in direct contact with the outer circumference 7.2.2 of the holding element.

[0094] The holding element is made of a material composed of silver, copper and aluminum oxide, for example. The distribution of the mass proportions is as follows: 92.5% silver, 7% copper and 0.5% aluminum oxide Al2O3. Here, for example, this material is used for the entire holding element 7.2.

[0095] The diameter D3 of the holding element 7.2 is, for example, 4 mm, and the diameter D7 of the transmitting insert 7.3 (see Figure 2.4 ) is, for example, 1.8 mm. This results in a wall thickness of the retaining element of 1.1 mm, and thus in a front annular surface 7.2.5 which extends radially outwards by 1.1 mm.

[0096] There is also the possibility that the material is present only in a part or in a region of the retaining element 7.2. Preferably, this is then the case at least on the inner surface 7.2.3 of the retaining element 7.2. The region preferably extends radially outwards by at least 0.5 mm from the inner surface 7.2.3. More preferably, the region extends radially outwards by at least 1 mm. This can be achieved, for example, in such a way that the proportion of aluminum oxide and / or the proportion of silver decreases radially outwards, while the proportion of copper increases.

[0097] The electrode holder 7 . 1 is made of at least one material with good electrical conductivity, and in this example, 99.9% of its main body is copper.

[0098] The body of the emitter insert preferably consists of at least 97% hafnium in this example. In the example, the remainder is essentially zirconium.

[0099] It is also possible to produce the electrode holder from only one material consisting of copper and aluminum oxide, for example, with a mass fraction of 99.5% copper and 0.5% aluminum oxide being given.

[0100] Figure 4 An electrode 7 according to another particular embodiment of the present invention is shown, wherein Figure 4 is a cross-sectional view through electrode 7, Figure 4.1 is a view A facing the front end 7.1.8 of the electrode 7. The electrode 7 has a front end 7.1.8 including a front face 7.1.1, a rear end 7.1.9, an outer surface 7.1.2 and a cavity 7.1.1 through which a coolant flows or can flow in the installed state. The electrode 7 comprises Figure 4.2 The electrode holder 7.1 shown in Figure 4.3 2 and the emission insert 7.3 are shown in FIG. The emission insert 7.3 is placed in the hole 7.2.1 of the holding element 7.2, which hole has a diameter D5.

[0101] The hole 7.2.1 of the retaining element 7.2 has an inner surface 7.2.3 which is in direct contact with the outer circumferential surface 7.3.2 of the emission insert 7.3.

[0102] A holding element 7.2 with an outer diameter D3 is pressed into a hole 7.1.5 of the electrode holder 7.1, which has an inner diameter D1. The hole 7.1.5 has an inner surface 7.1.3, which is in direct contact with the outer circumference 7.2.2 of the holding element 7.2. The holding element 7.2 can be connected to the electrode holder 7.1, for example, by force fit, form fit, but also by a thermal joining process, such as brazing, welding, in particular laser brazing, laser welding, arc brazing, arc welding, vacuum brazing, vacuum laser welding or electron beam welding. It is particularly preferred that the welding or brazing is carried out starting from the rear end 7.1.9 and the weld seam (weld seam, brazed seam) 7.4 is located in the cavity 7.1.7 extending to the rear end. Diffusion welding is also advantageous as a joining process, in which pressure and temperature are applied.

[0103] If the holding element 7.2 is thermally joined, for example soldered or welded, to the electrode holder 7.1 from the direction of the cavity 7.1.7, this has the following advantages over thermal joining from the front end:

[0104] - no welds are visible from the front, and

[0105] -No need for fine-tuning.

[0106] The holding element 7.2 is made here by way of example from a material consisting of copper and aluminum oxide. The distribution of the mass proportions is, for example, as follows: 99.3% copper and 0.7% aluminum oxide. This material is used here by way of example for the entire holding element 7.2.

[0107] The diameter D3 of the holding element 7.2 is, for example, 6 mm, and the diameter D7 of the transmitting insert 7.3 is, for example, 1.8 mm. This results in a wall thickness of the holding element 7.2 of 2.1 mm, and thus in a front annular surface 7.2.5 which extends radially outwards by 2.1 mm.

[0108] There is also the possibility that the material is present only in a part or in a region of the retaining element 7.2. Preferably, this is then the case at least on the inner surface 7.2.3 of the retaining element 7.2. The region preferably extends radially outwards by at least 0.5 mm from the inner surface. More preferably, the region extends radially outwards by at least 1 mm. This can be achieved, for example, in that the proportion of aluminum oxide and / or the proportion of silver decreases radially outwards, while the proportion of copper increases.

[0109] The electrode holder 7 . 1 is made of at least one material with good electrical conductivity, and in this example, 99.9% of its main body is copper.

[0110] The body of the emission insert preferably consists in this example of at least 97% hafnium.

[0111] Figure 5 An electrode 7 according to another particular embodiment of the present invention is shown, wherein Figure 5 is a cross-sectional view through electrode 7, Figure 5.1 is a perspective A facing the front end 7.1.8 of the electrode. The electrode 7 has a front end 7.1.8, a rear end 7.1.9, an outer surface 7.1.2 and a cavity 7.1.1 through which a coolant flows or can flow in the installed state. The electrode 7 comprises Figure 5.2 The electrode holder 7.1 shown by way of example in Figure 5.3 2 and the emission insert 7.3 are shown by way of example in FIG. The emission insert 7.3 is inserted into a hole 7.2.1 of the holding element 7.2, which hole has a diameter D5.

[0112] The hole of the retaining element 7.2 has an inner surface 7.2.3 which is in direct contact with the outer peripheral surface 7.3.2 of the emission insert.

[0113] The holding element 7.2 is mounted with its outer surface 7.2.2 on the front face 7.1.1 of the electrode holder 7.1 at the cylindrical section. The holding element 7.2 can be connected to the electrode holder 7.1, for example, by force fit, form fit, but also by a thermal joining process, such as brazing, welding, in particular laser brazing, laser welding, arc brazing, arc welding, vacuum brazing, vacuum laser welding or electron beam welding. It is particularly preferred that the welding or brazing is carried out starting from the rear end 7.1.9 and the weld seam (weld seam, brazed seam) 7.4 is located in the cavity 7.1.7 extending to the rear end. Diffusion welding is also advantageous as a joining process, in which pressure and temperature are applied.

[0114] The holding element 7.2 is made of a material composed of silver, copper and aluminum oxide, for example. The distribution of the mass proportions is as follows: 92% silver, 7.5% copper and 0.5% aluminum oxide. Here, for example, this material is used for the entire holding element 7.2.

[0115] The diameter D3 of the holding element 7.2 is, for example, 10 mm, and the diameter D7 of the transmitting insert is, for example, 1.8 mm. This results in a wall thickness of the holding element 7.2 of 4.1 mm, and thus in a front annular surface 7.2.5 which extends radially outwards by 4.1 mm.

[0116] There is also the possibility that the material is present only in a part or in a region of the retaining element 7.2. Preferably, this is then the case at least on the inner surface 7.2.3 of the retaining element 7.2. The region preferably extends radially outwards by at least 0.5 mm from the inner surface. More preferably, the region extends radially outwards by at least 1 mm. This can be achieved, for example, in that the proportion of aluminum oxide and / or the proportion of silver decreases radially outwards, while the proportion of copper increases.

[0117] The electrode holder 7 . 1 is made of at least one material having good electrical conductivity, and in this example 99.5% of its main body is copper.

[0118] The body of the emission insert preferably consists in this example of at least 97% hafnium.

[0119] Figure 6 Shows Figure 1 The nozzle 4 used. This nozzle 4 can be made, for example, completely of a material consisting of copper and aluminum oxide. However, it is essential that the area of ​​the nozzle that may come into contact with the plasma beam or the arc is made of this material. This is the case for the inner surface 4.2 of the nozzle opening 4.1. This can be achieved, for example, by fastening a nozzle insert 4.4 made of the material in the nozzle holder 4.3. Figure 6.1 This situation is exemplarily shown in FIG.

[0120] according to Figure 6 In the present example, the nozzle 4 is made of a material consisting of copper and aluminum oxide. The mass distribution is as follows: copper 99.7%, aluminum oxide 0.3%. Figure 6 This material is used by way of example for the entire nozzle 4 .

[0121] Figure 6.1 The nozzle insert 4.4 shown in the figure can be connected to the nozzle holder 4.3, for example, by force fit, form fit, but also by thermal joining processes such as brazing, welding, in particular laser brazing, laser welding, arc brazing, arc welding, vacuum brazing, vacuum laser welding or electron beam welding. Diffusion welding is also advantageous as a joining process, in which pressure and temperature are applied.

[0122] Figure 7 Shown according to Figure 1 The nozzle guard 9 can be made completely of a material consisting of copper and aluminum oxide. However, it is essential that the area of ​​the nozzle guard that may come into contact with the plasma beam or arc is made of this material. This is the case for the inner surface 9.2 of the nozzle guard 9. This can be achieved, for example, by fastening a nozzle guard insert 9.4 made of the material into a nozzle guard holder 9.3. Figure 7.1This situation is exemplarily shown in FIG.

[0123] according to Figure 7 In the present example, the nozzle shield 9 is made of a material consisting of copper and aluminum oxide. The mass ratio is, for example, as follows: 99.5% copper, 0.5% aluminum oxide. Here, this material is used for the entire nozzle shield 9 by way of example.

[0124] Figure 7.1 The nozzle guard insert 9.4 shown in the figure can be connected to the nozzle guard holder 9.3, for example, by force fit, form fit, but also by thermal joining processes such as brazing, welding, in particular laser brazing, laser welding, arc brazing, arc welding, vacuum brazing, vacuum laser welding or electron beam welding. Diffusion welding is also advantageous as a joining process, in which pressure and temperature are applied.

[0125] Figure 8 Shown according to Figure 1 The nozzle cap 2 of the plasma burner of the invention is made of a material consisting of copper and aluminum oxide. However, the key point is that the area of ​​the nozzle cap that may come into contact with the plasma beam or arc is made of this material. This is the case with the inner surface 2.2 of the nozzle cap 2. This can be achieved, for example, by fastening a nozzle cap insert 2.4 made of the material into a nozzle cap holder 2.3. Figure 8.1 This situation is exemplarily shown in FIG.

[0126] according to Figure 8 In the present example, the nozzle cap 2 is made of a material consisting of copper and aluminum oxide. The mass ratio is, for example, as follows: 99.5% copper, 0.5% aluminum oxide. Here, this material is used for the entire nozzle cap 2 by way of example.

[0127] Figure 8.1 The nozzle cap insert 2.4 shown in the figure can be connected to the nozzle cap holder 2.3, for example, by force fit, form fit, but also by thermal joining processes such as brazing, welding, in particular laser brazing, laser welding, arc brazing, arc welding, vacuum brazing, vacuum laser welding or electron beam welding. Diffusion welding is also advantageous as a joining process, in which pressure and temperature are applied.

[0128] In the above description, expressions such as "according to one embodiment" and "according to a particular embodiment" are used. They may be the same embodiment, but may also be different or another embodiment.

[0129] The features of the invention disclosed in the preceding description, in the drawings and in the claims may be essential for the realization of the invention in its various embodiments both individually and in any combination.

[0130] Reference numerals list

[0131] 1 Arc burner

[0132] 2 Nozzle cap

[0133] 2.1 Nozzle cap

[0134] 2.2 Inner surface of the nozzle cap

[0135] 2.3 Nozzle cap retainer

[0136] 2.4 Nozzle cap insert

[0137] 3 Plasma gas guide

[0138] 4 Nozzles

[0139] 4.1 Nozzle

[0140] 4.2 Inner surface of the nozzle

[0141] 4.3 Nozzle holder

[0142] 4.4 Nozzle insert

[0143] 5 Nozzle Container and Nozzle Cap Container

[0144] 6 Electrode holder

[0145] 7 Electrodes

[0146] 7.1 Electrode holder

[0147] 7.1.1 Front face

[0148] 7.1.2 External surface

[0149] 7.1.3 Inner surface

[0150] 7.1.5 Holes

[0151] 7.1.7 Cavity

[0152] 7.1.8 Frontend

[0153] 7.1.9 Backend

[0154] 7.2 Retaining elements

[0155] 7.2.1 Holes

[0156] 7.2.2 Outer Surface

[0157] 7.2.3 Inner surface

[0158] 7.2.5 Front annular surface

[0159] 7.3 Launch Insert

[0160] 7.3.1 Front face

[0161] 7.3.2 Outer Surface

[0162] 7.4 Welds

[0163] 8 Nozzle guard holder

[0164] 9 Nozzle guard

[0165] 9.1 Nozzle guard opening

[0166] 9.2 Inner surface of nozzle guard opening

[0167] 9.3 Nozzle guard retainer

[0168] 9.4 Nozzle guard insert

[0169] 10 Secondary gas guide

[0170] D1 inner diameter

[0171] D3 outer diameter

[0172] D5 inner diameter

[0173] D7 Diameter

[0174] L1 Length

[0175] L2 tempering ablation length

[0176] M Center longitudinal axis

[0177] PG Plasma Gas

[0178] SG Secondary Gas

[0179] WR1 Coolant circuit

[0180] WR2 Coolant circuit

[0181] WV1 Coolant inlet

[0182] WV2 Coolant circuit.

Claims

1. A component (2, 4, 5, 6, 7, 8, 9) for an arc burner (1), wherein the arc burner is operated in an energized manner, in particular, the component is for a plasma burner or a plasma cutting burner, characterized in that The member or at least one portion or at least one region of the member is made of a material including aluminum oxide and at least one of the chemical elements silver and copper.

2. The component (2, 4, 5, 6, 7, 8, 9) according to claim 1, wherein the proportion of silver or copper or the sum of silver and copper is at least 98% of the volume or mass of the material, more preferably, the proportion of silver or copper or the sum of silver and copper is at least 99% of the volume or mass of the material, and most preferably, the proportion of silver or copper or the sum of silver and copper is at least 99.5% of the volume or mass of the material.

3. The component (2, 4, 5, 6, 7, 8, 9) according to claim 1, wherein the proportion of aluminum oxide in the volume or mass of the material is at least 0.15%, more preferably, the proportion of aluminum oxide in the volume or mass of the material is at least 0.3%, and most preferably, the proportion of aluminum oxide in the volume or mass of the material is at least 0.5%.

4. A component (2, 4, 5, 6, 7, 8, 9) according to any of the preceding claims, wherein the proportion of aluminum oxide in the volume or mass of the material is not more than 2.0%, more preferably, the proportion of aluminum oxide in the volume or mass of the material is not more than 1.5%, and most preferably, the proportion of aluminum oxide in the volume or mass of the material is not more than 1.0%.

5. The component (2, 4, 5, 6, 7, 8, 9) according to any one of claims 1 to 4, wherein the component is a wear part for an arc burner (1).

6. The component (7) according to claim 5, wherein the wear part is an electrode (7) for an arc burner (1).

7. A component (7) according to claim 6, wherein the electrode (7) has a front end (7.1.8) and a rear end (7.1.9), the electrode extends along a longitudinal axis M, and the electrode has at least one transmitting insert (7.3) located at the front end (7.1.8) and has an electrode holder (7.1), and if necessary, the electrode also has a holding element (7.2) for the transmitting insert (7.3).

8. A component (7) according to claim 7, wherein at least one section of the inner surface (7.1.3) of the electrode holder (7.1) or at least one section of the inner surface (7.2.3) of the holding element (7.2) which is in contact with the emission insert (7.3) is made of the material.

9. A component (7) according to claim 8, wherein the material extends radially outward by at least 0.5 mm starting from at least the section of the inner surface (7.1.3) of the electrode holder (7.1) or from the section of the inner surface (7.2.3) of the retaining element (7.2), more preferably, the material extends radially outward by at least 1 mm starting from at least the section of the inner surface (7.1.3) of the electrode holder (7.1) or from the section of the inner surface (7.2.3) of the retaining element (7.2), and most preferably, the material extends radially outward by at least 1.3 mm starting from at least the section of the inner surface (7.1.3) of the electrode holder (7.1) or from the section of the inner surface (7.2.3) of the retaining element (7.2).

10. The component (7) according to any one of claims 7 to 9, wherein at least one section of a front face (7.1.1) comprises the material, the at least one section of the front face being in close proximity to the front face (7.3.1) of the emission insert (7.3).

11. A component (7) according to claim 10, wherein the segment of the front end face (7.1.1) extends radially outward by at least 0.5 mm, more preferably, the segment of the front end face (7.1.1) extends radially outward by at least 1 mm, and most preferably, the segment of the front end face (7.1.1) extends radially outward by at least 1.3 mm.

12. Component (7) according to any one of claims 7 to 11, wherein the emission insert (7.3) consists of at least 90% by volume or mass of hafnium or zirconium or tungsten.

13. The component (4) according to claim 5, wherein the wear part is a nozzle (4) having at least one nozzle opening (4.1).

14. The component (4) according to claim 13, wherein at least a section of the inner surface (4.2) of the nozzle opening (4.1) comprises the material.

15. A component (4) according to claim 14, wherein the material extends radially outward by at least 0.5 mm starting from at least the section of the inner surface (4.2) of the nozzle mouth (4.1), more preferably, the material extends radially outward by at least 1 mm starting from at least the section of the inner surface (4.2) of the nozzle mouth (4.1), and most preferably, the material extends radially outward by at least 1.3 mm starting from at least the section of the inner surface (4.2) of the nozzle mouth (4.1).

16. The component (9) according to claim 5, wherein the wear part is a nozzle shroud (9) having at least one nozzle shroud opening (9.1).

17. The component (9) according to claim 16, wherein at least a section of the inner surface (9.2) of the nozzle guard opening (9.1) comprises the material.

18. A component (9) according to claim 17, wherein the material extends radially outward by at least 0.5 mm starting from the section of the inner surface (9.2) of the nozzle guard mouth (9.1), more preferably, the material extends radially outward by at least 1 mm starting from the section of the inner surface (9.2) of the nozzle guard mouth (9.1), and most preferably, the material extends radially outward by at least 1.3 mm starting from the section of the inner surface (9.2) of the nozzle guard mouth (9.1).

19. The component (2) according to claim 5, wherein the wear part is a nozzle cap (2) having at least one nozzle cap opening (2.1).

20. The component (2) according to claim 19, wherein at least a section of the inner surface (2.2) of the nozzle cap opening (2.1) comprises the material.

21. A component (2) according to claim 20, wherein the material extends radially outward by at least 0.5 mm starting from the section of the inner surface (2.2) of the nozzle cap mouth (2.1), more preferably, the material extends radially outward by at least 1 mm starting from the section of the inner surface (2.2) of the nozzle cap mouth (2.1), and most preferably, the material extends radially outward by at least 1.3 mm starting from the section of the inner surface (2.2) of the nozzle cap mouth (2.1).

22. The component (5, 6, 8) according to any one of claims 1 to 4, wherein the component is a housing or holder for at least one wear part (2 or 4 or 7 or 9), the housing or holder being used for an arc burner (1).

23. The component (5, 6, 8) according to claim 22, wherein the housing (5, 6, 8) or the holder is a nozzle housing (5), a nozzle cap housing (5) or an electrode housing (6) or a nozzle shield housing (8).

24. Arc burner having at least one component according to any of the preceding claims.

25. The arc burner according to claim 24, wherein the arc burner is a plasma burner or a plasma cutting burner.

26. Method for plasma cutting using an arc burner according to claim 25, wherein the plasma cutting burner is operated with oxygen, an oxygen-containing gas or gas mixture, and / or a reducing gas or gas mixture, and / or an inert gas or an inert gas mixture as plasma gas (PG) and / or secondary gas (SG).

27. A method for plasma cutting using an arc burner according to claim 25, wherein the plasma cutting burner is operated with oxygen or a gas mixture containing oxygen as plasma gas (PG) and / or secondary gas (SG), and in the oxygen-containing gas mixture, the oxygen content of the gas mixture is at least 25 volume percent.

28. A method for plasma cutting using an arc burner according to claim 25, wherein the plasma cutting burner is operated with argon or a gas mixture containing argon as plasma gas (PG) and / or secondary gas (SG), and in the gas mixture containing argon, argon accounts for at least 25 volume percent of the gas mixture.

29. The method according to any one of claims 26 to 28, wherein the at least one component (2, 4, 5, 6, 7, 8, 9) or the components (2, 4, 5, 6, 7, 8, 9) among at least one component.

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