EP2014794A1 - Cold gas jet nozzle - Google Patents

Abstract

The nozzle (100) accelerates gases and sprayed particles. At the region of smallest diameter (10), the converging section (20) transitions into a non-converging section (30). In part of this region (10), or in the non-converging section, the nozzle is made from heat-resistant plastic. This comprises one or more of a: polyether ketone (PEK), polyimide (PI), polytetrafluoroethylene (PTFE), fiber-reinforced plastic and MICA (sic). It has a melting point exceeding 250[deg] C, which is preferably over 400[deg] C. The non-converging section is hollow-cylindrical or divergent. The nozzle is made from two semi-shells. The convergent and non-convergent sections are separably-connected, at the constriction. They are screwed or clamped together there, directly or indirectly, using a connector (40). The three sections are made of differing materials. At least that part of the converging section contacting gas and sprayed particles, is made of a material with a melting point exceeding 300[deg] C or 600[deg] C. It preferably exceeds 1500[deg] C. In examples, the converging section is metal, metal alloy, carbide, oxide or other hard material. The non converging section and/or connector, at least in the region contacting gas and particles, is made of the heat-resistant plastic. In a further variant, all three sections are made of the heat-resistant plastic. A detailed series of inequalities describes alternative relative diameters of the sections. About 5-50 wt% of calcium fluoride is included in the polytetrafluoroethylene. The plastic contains glass- or carbon fiber reinforcement. The nozzle is incorporated in a spraying gun.

Description

Kaltgasspritzdüse Technical area

The present invention relates to a cold gas spraying nozzle according to the preamble of claim 1.

State of the art

Cold gas spraying is a coating process in which a powdered coating material is applied to a carrier material at very high speed. For this purpose, the powder particles are injected into a gas jet of heated process gas, wherein the gas jet was previously accelerated to supersonic speed by expansion in a mostly laval-like shaped nozzle.

The injected spray particles are accelerated by injection into the gas jet to such a high speed that, in contrast to other thermal spray processes, they form a dense and firmly adhering layer upon impact with the substrate even without prior melting or melting.

Nozzles for cold gas spraying are produced from metal, from metal alloys, from light metal, for example from aluminum, or from hard material, for example from tungsten carbide. Both full nozzles and split nozzles, for example nozzles composed of two half-shells, can be used for cold gas spraying.

Devices for cold gas spraying are in the prior art, for example, from the publications EP 484 533 . DE 100 15 920 A1 . DE 102 07 525 A1 . EP 1 369 498 A1 . EP 1 506 816 A1 . EP 1 629 899 A1 . WO 03/041868 A2 or WO 2006/034778 A1 known.

In the publication DE 102 07 519 A1 The prior art discloses a ceramic insert made of ceramics which is used in the region of the narrowest cross section of the cold gas spraying nozzle in order to achieve a high wear resistance of the cold gas spraying nozzle.

A cold gas spray nozzle in which the converging section is detachably connected to the non-converging section in the area of the smallest diameter describes the document JP 2005 095 886 A from the prior art. Such a detachable connection offers, for example, the advantage that when the nozzle neck is worn, it is not necessary to replace the entire nozzle. Further, depending on the application and desired gas velocity, a non-convergent section may be used with any divergence angle.

From the publication WO 03/041868 A2 From the prior art, a cold gas spray nozzle is known, which has at least two parts in the flow direction, wherein the second part is easily replaceable. In this case, these two parts may be formed of different materials, for example of metallic material, of ceramic and / or plastic.

However, spattering of low-melting materials, such as aluminum or zinc (and their alloys), sometimes results in caking in the nozzle, resulting in significant disturbances to the injection process.

A cold gas spraying nozzle according to the preamble of claim 1 is in the document EP 1 462 546 B1 (German translation: DE 60 2004 000 936 T2 ) disclosed in the prior art. In this cold gas spray nozzle, at least the non-converging region of polybenzimidazole (PBI) is formed to prevent clogging of the nozzle when using low-melting powder particles.

Polybenzimidazole has the formula poly (2,2 '- (m-phenylene) -5,5'-bibenzimidazole) and is commercially available under the trade name Celazole. Polybenzimidazole is particularly suitable for use in a cold gas spray nozzle because of its very high temperature resistance. Thus, polybenzimidazole allows for continuous use temperatures in excess of about 310 degrees Celsius. Furthermore, polybenzimidazole has a high and above a wide temperature range almost constant mechanical strength.

However, due to its extreme hardness, polybenzimidazole can become a chipping challenge. So it is recommended to provide edging to avoid tearing of edges during cutting. Furthermore, in the part design, the relatively high notch sensitivity of polybenzimidazole must be taken into account, that is, corners must be rounded. In addition to the difficult processability, the relatively high price is another disadvantage of the thermoplastic polybenzimidazole.

Furthermore, polybenzimidazole poses specific requirements for storage. For example, precast parts machined to tight tolerances are to be stored in airtight bags provided with a desiccant in order to prevent dimensional changes due to absorption of moisture. Moist parts that are quickly exposed to temperatures above 200 degrees Celsius during operation should first be dried before use to avoid deformation due to thermal shock.

Presentation of the present invention: object, solution, advantages

Based on the disadvantages and inadequacies set out above and in appreciation of the outlined prior art, the present invention has the object, a cold gas spray nozzle of the type mentioned in such a way that clogging of the cold gas spray nozzle is reliably prevented with spray particles and the cold gas spray nozzle yet easy and is inexpensive to produce.

This object is achieved by a cold gas spraying nozzle having the features specified in claim 1. Advantageous embodiments and expedient developments of the present invention are characterized in the dependent claims.

Thus, the present invention is based on the fact that the cold gas spraying nozzle is made of at least one heat-resistant plastic, which is easily processable in comparison with polybenzimidazole, at least in that region in which the spray particles cake gently, in particular in the nozzle neck or in the narrowest cross-section of the nozzle. Advantageously, the plastic from which the nozzle is formed at least in the region of its smallest diameter, a melting point of about about 250 degrees Celsius, for example, of about about 300 degrees Celsius, in particular of about about 400 degrees Celsius on.

• Polyetheretherketon (PEEK) mit einer Schmelztemperatur von 335 Grad Celsius und/oder
• Polyetherketonketon (PEKK) mit einem Schmelzpunkt von 391 Grad Celsius eingesetzt werden.

According to the present invention, as a heat-resistant plastic, for example, at least one high-temperature resistant thermoplastic material from the group of polyether ketones (PEK), in particular

• Polyetheretherketone (PEEK) with a melting temperature of 335 degrees Celsius and / or
• Polyether ketone ketone (PEKK) can be used with a melting point of 391 degrees Celsius.

Polyether ketones have high mechanical strength, stiffness and creep resistance over a wide temperature range; Nevertheless, polyether ketones are relatively easy to work, for example by machining. Another advantage of polyether ketones is their inherent flame retardancy and very little smoke in case of fire. Furthermore, polyether ketones have excellent wear resistance and good sliding properties. Caking of the spray particles is thus prevented in a reliable manner.

• eine hohe mechanische Festigkeit, Härte, Steifigkeit und Zähigkeit,
• ein hohes mechanisches Dämpfungsvermögen,
• eine gute Ermüdungsfestigkeit,
• eine sehr hohe Verschleißfestigkeit,
• gute Gleit- und Notlaufeigenschaften,
• eine gute Bearbeitbarkeit, insbesondere mittels Spanen, sowie
• eine gute Temperaturbeständigkeit.

Alternatively or in addition to polyether ketone, the heat-resistant plastic may also be substantially of polyimide (PI); central properties of polyimide sold, for example, by DuPont under the tradename Vespel

• high mechanical strength, hardness, rigidity and toughness,
• a high mechanical damping capacity,
• a good fatigue resistance,
• a very high wear resistance,
• good sliding and emergency running properties,
• a good machinability, especially by means of cutting, as well
• a good temperature resistance.

Polyimide can be used in a temperature range between absolute zero and be used in the short term to well above 400 degrees Celsius. Here, the thermal and electrical conductivity of polyimide is very low. Further, polyimide has a relatively low coefficient of thermal expansion and a good dimensional stability for a plastic, and thus enables the production of components with close tolerances. Another advantage is the fact that the properties of polyimide, for example, by adding graphite or polytetrafluoroethylene (PTFE) can be selectively changed.

As an alternative or in addition to the aforementioned plastics, the heat-resistant plastic of the cold gas spraying nozzle according to the present invention can also be formed from polytetrafluoroethylene (PTFE).

Polytetrafluoroethylene, colloquially also known under the trade name Teflon, is particularly advantageous because it has a very low coefficient of friction. There is almost no material adhering to polytetrafluoroethylene because the surface tension of polytetrafluoroethylene is extremely low. Caking of injected into the gas jet spray particles on the inner wall of the cold gas spray nozzle is prevented by a lining with polytetrafluoroethylene in a particularly reliable manner. Further, polytetrafluoroethylene has a very good workability.

According to an advantageous embodiment of the present invention, the polytetrafluoroethylene has calcium fluoride, more particularly a content range of from about fifteen percent by weight calcium fluoride to about fifty percent by weight calcium fluoride, for example a content of about 25 percent by weight calcium fluoride or about forty percent by weight calcium fluoride.

As an alternative or in addition to the above-mentioned plastics, according to the present invention, the heat-resistant plastic may further be formed essentially of fiber-reinforced plastic, in particular of glass fiber reinforced and / or carbon fiber reinforced and / or carbon fiber reinforced plastic; this offers the advantage of less deformability.

Fiber-plastic composites generally have high specific strengths and stiffnesses. Here, the mechanical and thermal properties of fiber-plastic composites can be adjusted via a variety of parameters. Further, in addition to the fiber-matrix combination, for example, the fiber angle, the fiber volume ratio and / or the layer order can be varied and thus a particularly easy workability can be achieved.

As an alternative or in addition to the aforementioned plastics, according to the present invention, the heat-resistant plastic may finally be formed essentially of MICA.

In order to avoid swirling of the gas and the spray particles (such turbulence is disadvantageous, because this the speed of the gas or the spray particles and thus the application energy of the spray particles is reduced), can in an advantageous embodiment of the present invention, the smallest diameter of the convergent section of smallest diameter of the non-converging portion, in particular, the smallest diameter of the converging portion is smaller than the smallest diameter of the non-converging portion.

Alternatively or additionally, the diameter of the part of the connecting element facing the convergent section may differ from the diameter of the part of the convergent section facing the connecting element, in particular the diameter of the part of the connecting element facing the convergent section greater than the diameter of the part of the convergent section facing the connecting element be.

Alternatively or additionally, the diameter of the part of the connecting element facing the non-converging section may differ from the diameter of the part of the non-converging section facing the connecting element, in particular the diameter of the part of the connecting element facing the non-converging section is smaller than the diameter of the connecting element Be connecting member facing part of the non-converging section.

The present invention further relates to a cold gas spray gun with at least one cold gas spray nozzle according to the type set forth above.

Brief description of the drawings

As already explained above, there are various possibilities for designing and developing the teaching of the present invention in an advantageous manner. Reference is made on the one hand to the claims subordinate to claim 1, on the other hand further embodiments, features and advantages of the present invention will be described below, inter alia, with reference to the Fig. 1 to Fig. 4C illustrated five embodiments explained in more detail.

Fig. 1

in schematischer Darstellung ein erstes Ausführungsbeispiel einer Kaltgasspritzdüse gemäß der vorliegenden Erfindung;

Fig. 2

in schematischer Darstellung ein zweites Ausführungsbeispiel einer Kaltgasspritzdüse gemäß der vorliegenden Erfindung;

Fig. 3

in schematischer Darstellung ein drittes Ausführungsbeispiel einer Kaltgasspritzdüse gemäß der vorliegenden Erfindung;

Fig. 4A

in schematischer Darstellung ein viertes Ausführungsbeispiel einer Kaltgasspritzdüse gemäß der vorliegenden Erfindung;

Fig. 4B

in schematischer Darstellung ein fünftes Ausführungsbeispiel einer Kaltgasspritzdüse gemäß der vorliegenden Erfindung; und

Fig. 4C

in schematischer Darstellung eine Detailansicht der Kaltgasspritzdüse aus Fig. 4A bzw. aus Fig. 4B.

It shows:

Fig. 1

a schematic representation of a first embodiment of a cold gas spray nozzle according to the present invention;

Fig. 2

a schematic representation of a second embodiment of a cold gas spraying nozzle according to the present invention;

Fig. 3

a schematic representation of a third embodiment of a cold gas spraying nozzle according to the present invention;

Fig. 4A

a schematic representation of a fourth embodiment of a cold gas spraying nozzle according to the present invention;

Fig. 4B

a schematic representation of a fifth embodiment of a cold gas spraying nozzle according to the present invention; and

Fig. 4C

in a schematic representation of a detailed view of the cold gas spray nozzle Fig. 4A or off Fig. 4B ,

Same or similar embodiments, elements or features are in Fig. 1 to Fig. 4C provided with identical reference numerals.

Best way to carry out the present invention

• sowohl auf das in Fig. 1 dargestellte erste Ausführungsbeispiel einer Kaltgasspritzdüse 100 gemäß der vorliegenden Erfindung
• als auch auf das in Fig. 2 dargestellte zweite Ausführungsbeispiel einer Kaltgasspritzdüse 100' gemäß der vorliegenden Erfindung
• als auch auf das in Fig. 3 dargestellte dritte Ausführungsbeispiel einer Kaltgasspritzdüse 100" gemäß der vorliegenden Erfindung
• als auch auf das in Fig. 4A und in Fig. 4C dargestellte vierte Ausführungsbeispiel einer Kaltgasspritzdüse 100"' gemäß der vorliegenden Erfindung
• als auch auf das in Fig. 4B und in Fig. 4C dargestellte fünfte Ausführungsbeispiel einer Kaltgasspritzdüse 100"" gemäß der vorliegenden Erfindung.

In order to avoid unnecessary repetition, the following explanations relate to the embodiments, features and advantages of the present invention (unless stated otherwise).

• both on the in Fig. 1 illustrated first embodiment of a cold gas spray nozzle 100 according to the present invention
• as well as on in Fig. 2 illustrated second embodiment of a cold gas spray nozzle 100 'according to the present invention
• as well as on in Fig. 3 illustrated third embodiment of a cold gas spray nozzle 100 "according to the present invention
• as well as on in Fig. 4A and in Fig. 4C illustrated fourth embodiment of a cold gas spray nozzle 100 "'according to the present invention
• as well as on in Fig. 4B and in Fig. 4C illustrated fifth embodiment of a cold gas spray nozzle 100 "" according to the present invention.

I'm referring Fig. 1 In the first exemplary embodiment of the present invention, a cold gas spraying nozzle 100 (with orifice 210, powder tube 220 and gas chamber 50) provided for accelerating gas and spray particles is shown, which in the region 10 of its smallest diameter from a direction converging in the flow direction S 20 in a flow direction S non-converging section 30 passes.

In order to prevent clogging of the nozzle 100 with spray particles, in particular when using low-melting material, for example aluminum, the cold gas spray nozzle 100 is formed in the region 10 of the smallest diameter of heat-resistant plastic.

It is thus possible for the convergent section 20, the non-converging section 30 and / or at least one connecting element 40 to differ in the material.

• der konvergierende Abschnitt 20 überwiegend aus Metall und/oder überwiegend aus mindestens einer Metalllegierung und/oder überwiegend aus mindestens einem Hartstoff, beispielsweise aus Wolframcarbid, und
• der nicht-konvergierende Abschnitt 30 und/oder das Verbindungselement 40 überwiegend aus dem hitzebeständigen Kunststoff

gebildet sein.For example, as in Fig. 2 and in 4B shown,

• the convergent section 20 predominantly of metal and / or predominantly of at least one metal alloy and / or predominantly of at least one hard material, for example of tungsten carbide, and
• the non-converging portion 30 and / or the connecting member 40 mainly made of the heat-resistant plastic

be formed.

In such a partial production of the nozzle according to the invention from appropriate heat-resistant plastic, the part made of plastic advantageously begins in the region 10 of the thinnest cross-section of the nozzle, so that the region in which the gas expands, is made of plastic.

In a split-fabricated embodiment of the cold gas spray nozzle 100 'or 100 "" (see. Fig. 2 respectively. Fig. 4B ), in which the first segment, ie the converging section 20, is formed of metal, of at least one metal alloy, of carbide, of oxide and / or of at least one hard material, can be operated at higher gas temperatures than with a cold gas spraying nozzle made entirely of plastic become.

The temperature of the gas fed into the cold gas spraying nozzle 100 'or 100 "" can be selected arbitrarily high, because at the narrowest cross section 10 of the nozzle 100' or 100 "", ie at the expansion location, the gas suddenly becomes cold. Even if the cold gas spray nozzle is fed with 600 degrees Celsius hot gas, the gas temperature at the point where the heat resistant plastic starts is less than 300 degrees Celsius.

Since the gas velocity within the cold gas spraying nozzle depends on the temperature of the gas fed into the cold gas spraying nozzle, it is particularly advantageous if the cold gas spraying nozzle 100 'or 100 "" can be supplied with gas having a temperature of over 310 degrees Celsius, in particular above 600 degrees Celsius, for example, of over about 1,500 degrees Celsius, has. In this way, higher gas velocities and thus also higher particle speeds can be achieved, which in turn leads to more efficiency and better layers.

As in the fourth embodiment of the cold gas spray nozzle 100 "'in Fig. 4A however, the entire nozzle, that is to say the convergent section 20, the non-converging section 30 and / or the connecting element 40, may also be formed from the heat-resistant plastic. Here, the nozzle can be built from two half shells or a full nozzle.

• aus mindestens einem Kunststoff aus der Gruppe der Polyetherketone (PEK) und/oder
• aus Polyimid (PI) und/oder
• aus Polytetrafluorethylen (PTFE) und/oder
• aus faserverstärktem Kunststoff und/oder
• aus MICA.

The heat-resistant plastic consists essentially

• from at least one plastic from the group of polyether ketones (PEK) and / or
• of polyimide (PI) and / or
• made of polytetrafluoroethylene (PTFE) and / or
• made of fiber-reinforced plastic and / or
• from MICA.

As in Fig. 1 , in Fig. 2 and in Fig. 4A 1, the non-converging portion 30 of the cold gas spraying nozzle may be diverging in the flow direction S. This helps to accelerate the gas.

However, non-converging portion 30 may also be hollow cylindrical or substantially hollow cylindrical, such as in the third embodiment of cold gas spray nozzle 100 ".

Particularly advantageously, the convergent section 20 is releasably connected to the non-convergent section 30 in the region 10 of the smallest diameter. This is in Fig. 1 , in Fig. 2 and in Fig. 3 illustrated by a vertical dashed line.

• unmittelbar (vgl. Fig. 1, Fig. 2, Fig. 4A, Fig. 4B, Fig. 4C) oder
• mittelbar (vgl. Fig. 3) über das zum Beispiel als Überbrückungsteil oder als Übergangsstück

ausgebildete Verbindungselement 40 verschraubbar und/oder verklemmbar sein. Im vierten Ausführungsbeispiel der Kaltgasspritzdüse 100"' (vgl. Fig. 4A, Fig. 4C) ist beispielsweise der konvergierende Abschnitt 20 unmittelbar über eine Schraub- oder Klemmverbindung 40 mit dem nicht-konvergierenden Abschnitt 30 verbunden.Here, the converging portion 20 may be connected to the non-converging portion 30

• directly (cf. Fig. 1, Fig. 2 . Fig. 4A, Fig. 4B . Fig. 4C ) or
• indirectly (cf. Fig. 3 ) about that, for example, as a bridging part or as a transition piece

trained connecting element 40 can be screwed and / or clamped. In the fourth embodiment of the cold gas spray nozzle 100 "'(see. Fig. 4A . Fig. 4C For example, the converging portion 20 is directly connected to the non-converging portion 30 via a screw or clamp connection 40.

According to a particularly advantageous, based Fig. 4A, Fig. 4B and Fig. 4C illustrated embodiment of the present invention differs the least Diameter of the converging portion 20 or the converging portion 20 facing portion 42 of the connecting member 40 of the smallest diameter of the non-converging portion 30 or the non-converging portion 30 facing portion 44 of the connecting element 40th

In particular, the smallest diameter of the converging portion 20 or the converging portion 20 facing portion 42 of the connecting member 40 is smaller than the smallest diameter of the non-converging portion 30 or the non-converging portion 30 facing portion 44 of the connecting element 40th

This slight misalignment of the converging portion 20 and the non-converging portion 30 serves to avoid swirling of the gas and spray particles. Turbulences of this type are disadvantageous, since this reduces the velocity of the gas or the spray particles and thus the application energy of the spray particles. By means of the heat-resistant plastics selected according to the invention, a nozzle with such an offset is particularly easy to produce, and this nozzle is also very durable.

LIST OF REFERENCE NUMBERS

100

Cold gas spraying nozzle (= first embodiment; Fig. 1 )

100 '

Cold gas injection nozzle (= second embodiment; Fig. 2 )

100 '

Cold gas injection nozzle (= third embodiment; Fig. 3 )

100 ' "

Cold gas spraying nozzle (= fourth embodiment; Fig. 4A . Fig. 4C )

100 ""

Cold gas spraying nozzle (= fifth embodiment; Fig. 4B . Fig. 4C )

10

Lowest Diameter Range of Cold Spray Nozzle 100, 100 ', 100 ", 100"', 100 ""

20

in the flow direction S converging or convergent section of the cold gas spray nozzle 100, 100 ', 100 ", 100"', 100 ""

22

the connecting element 40 facing part of the converging portion 20th

30

Non-converging or non-convergent, in particular hollow-cylindrical or diverging in the flow direction S, section of the cold gas spraying nozzle 100, 100 ', 100 ", 100"', 100 ""

32

The connecting element 40 or the converging portion 20 facing part of the non-converging portion 30th

40

Connecting element, in particular bridging part or transition piece

42

the converging portion 20 facing part of the connecting element 40th

44

the non-converging portion 30 facing part of the connecting element 40th

50

Gas chamber of the cold gas spraying nozzle 100, 100 ', 100 ", 100"', 100 ""

210

cover

220

powder tube

S

flow direction

Claims (13)

For accelerating gas and spray particles provided cold gas spray nozzle (100, 100 ', 100 ", 100"', 100 ""), - which in the region (10) of its smallest diameter of a converging in the flow direction (S) section (20) in a non-converging section (30) passes over and - at least - In at least a portion, in particular in at least one section, their smallest diameter (10) and / or in at least one subregion, in particular in at least one subsection, of its non-converging section (30)
is formed of at least one heat-resistant plastic,
characterized,
that the heat-resistant plastic is essentially - Of at least one plastic from the group of polyether ketones (PEK) and / or - Of polyimide (PI) and / or - Of polytetrafluoroethylene (PTFE) and / or - Of fiber-reinforced plastic and / or - from MICA is formed. Kaltgasspritzdüse according to claim 1, characterized in that the heat-resistant plastic has a melting point of about about 250 degrees Celsius, in particular of about about 400 degrees Celsius. Kaltgasspritzdüse according to claim 1 or 2, characterized in that the non-converging portion (30) is hollow cylindrical or diverging in the flow direction (S). Cold gas spraying nozzle according to at least one of claims 1 to 3, characterized in that the cold gas spraying nozzle (100, 100 ', 100 ", 100"', 100 "") is made of two half-shells. A cold gas spray nozzle according to any one of claims 1 to 4, characterized in that the converging portion (20) is releasably connected to the non-converging portion (30) in the region (10) of the smallest diameter. Kaltgasspritzdüse according to claim 5, characterized in that the converging portion (20) with the non-converging portion (30), in particular directly or in particular indirectly, via at least one connecting element (40) is screwed and / or clamped. Kaltgasspritzdüse according to any one of claims 1 to 6, characterized in that the convergent portion (20), the non-converging portion (30) and / or the connecting element (40) differ in the material, in particular that - The converging portion (20) is formed at least in at least in contact with the gas and with the spray particles at least predominantly from at least one material having a melting point of about about 300 degrees Celsius, in particular of about 600 degrees Celsius, for example from about about 1,500 degrees Celsius, for example, that the converging portion (20) predominantly of metal and / or predominantly of at least one metal alloy and / or predominantly of carbide and / or predominantly oxide and / or predominantly of at least one hard material and - The non-converging portion (30) and / or the connecting element (40) are at least predominantly formed of the heat-resistant plastic, at least in the area coming into contact with the gas and the spray particles. Kaltgasspritzdüse according to any one of claims 1 to 7, characterized in that the converging portion (20), the non-converging portion (30) and / or the connecting element (40) are formed from the heat-resistant plastic. Cold gas spraying nozzle according to at least one of claims 1 to 8, characterized - That the smallest diameter of the convergent portion (20) of the least Diameter of the non-converging portion (30) differs, in particular that the smallest diameter of the converging portion (20) is smaller than the smallest diameter of the non-converging portion (30), and / or - That the diameter of the convergent portion (20) facing part (42) of the connecting element (40) from the diameter of the connecting element (40) facing part (22) of the converging portion (20) differs, in particular that the diameter of the converging portion (20) facing part (42) of the connecting element (40) is greater than the diameter of the connecting element (40) facing part (22) of the converging portion (20), and / or - - that the diameter of the non-converging portion (30) facing part (44) of the connecting element (40) from the diameter of the connecting element (40) facing part (32) of the non-converging portion (30) differs, in particular that the Diameter of the non-converging portion (30) facing part (44) of the connecting element (40) is smaller than the diameter of the connecting element (40) facing part (32) of the non-converging portion (30). Cold gas spraying nozzle according to at least one of claims 1 to 9, characterized in that the heat-resistant plastic from the group of polyether ketones (PEK) is a polyetheretherketone (PEEK) and / or a polyetherketone ketone (PEKK). A cold gas spray nozzle according to at least one of claims 1 to 10, characterized in that the polytetrafluoroethylene (PTFE) is calcium fluoride, in particular a content range from about fifteen percent by weight calcium fluoride to about fifty percent by weight calcium fluoride, for example a content of about 25 percent by weight calcium fluoride or about forty percent by weight calcium fluoride, having. Kaltgasspritzdüse according to any one of claims 1 to 11, characterized in that the fiber-reinforced plastic is glass fiber reinforced and / or carbon fiber reinforced. Cold gas spray gun with at least one cold gas spray nozzle (100, 100 ', 100 ", 100"', 100 "") according to at least one of claims 1 to 12.

Images