Non-transfer rotating arc plasma thermal spraying spray gun

Abstract

The utility model relates to a non-transfer rotating arc plasma thermal spraying gun which comprises a spraying gun body, the spraying gun body is matched with a distribution ring, the spraying gun body is provided with a spraying opening, the distribution ring is provided with a plurality of spiral air distribution holes, and the outer side of the spraying gun body is sleeved with an electromagnetic intervention block. And the electromagnetic intervention block is arranged between the distribution ring and the jet orifice. A beam of gas at a gas inlet is uniformly classified through a gas distribution ring and a plurality of spiral gas distribution holes, so that plasma gas around the cathode of the spray gun is uniformly distributed, and the straight-through gas changes the gas flow direction through the angle of a small hole, so that the gas passes through a vortex rotating gas flow in a cavity formed by the cathode and the anode.

Description

Technical Field

[0001] The utility model relates to the technical field of spraying spray guns, in particular to a non-transferred rotating arc plasma thermal spraying spray gun. Background Art

[0002] Plasma thermal spray coating technology is to heat the materials that need coating, such as metals and ceramics, with the heat source of plasma energy to make the materials reach a molten or molten state and form molten droplets, which are quickly sprayed onto the surface of equipment parts to form a coating, so that the surface of the parts has various functions such as wear resistance, corrosion resistance, high hardness, insulation, etc., to achieve the purpose of surface modification and improvement of parts. Thermal spraying technology was born in 1906. After more than a hundred years of development, it has developed from the initial simple flame wire spray gun to the current high-power, high-speed, automated plasma spray system, supersonic flame spray system, laser cladding system, etc., which not only enhances the performance of the coating, but also develops from a single metal coating to the current metal coating, alloy coating, metal ceramic coating, ceramic coating, polymer coating and other types of multifunctional coating systems. Today, thermal spray coating technology has been applied in various industries such as petroleum, chemical, steel, papermaking, aviation, electricity, semiconductors, flat panel displays, etc., and plays different functions and roles on the surfaces of equipment and parts in various industries.

[0003] However, during the spraying process of the existing plasma thermal spray gun, the plasma flow is relatively dispersed and the arc control is unstable, resulting in unstable output power of the spray gun and insufficient heating and melting of the material. Utility Model Content

[0004] In order to achieve the purpose of the utility model, the technical solution adopted by the utility model is: a non-transferred rotating arc plasma thermal spray gun, comprising: a spray gun body, the spray gun body is equipped with a distribution ring, the spray gun body is provided with an injection port, the distribution ring is provided with a plurality of spiral air distribution holes, and an electromagnetic intervention block is provided on the outer side of the spray gun body, and the electromagnetic intervention block is arranged between the distribution ring and the injection port.

[0005] Preferably, the electromagnetic intervention block is formed by splicing four anode blocks equally divided into 90° in the circumferential direction.

[0006] Preferably, the outer surface of the spray gun body is provided with guide ribs for guiding the anode block.

[0007] Preferably, the outer surface of the spray gun body is provided with a circular limiting rib that cooperates with the anode block.

[0008] Preferably, a plurality of glue openings are provided on the outer surface of the spray gun body and the contact surface with the anode block.

[0009] Preferably, a feed port is provided on the outer surface of the spray gun body.

[0010] Preferably, the spray gun body is provided with a conical cathode.

[0011] Compared with the prior art, the beneficial effects of the utility model are:

[0012] 1. A gas beam from the air inlet is evenly classified through a gas distribution ring through multiple spiral gas distribution holes, so that the plasma gas around the cathode of the spray gun is evenly distributed, and the straight gas passes through the small hole at an angle to change the gas flow direction, so that the gas swirls in the chamber formed by the cathode and anode.

[0013] 2. The gas is driven into the spray gun body through multiple spiral gas distribution holes, and the plasma flow is more concentrated through the magnetic field intervention of the external electromagnetic intervention block.

[0014] 3. The electromagnetic intervention block is composed of 4 circumferential anode blocks equally divided at 90°. The position where the arc is generated when power is turned on generally occurs at the four spliced ​​contact points. This can not only make the arc starting position controllable and the arc stable, but also increase the output power of the spray gun, so that the material can be heated and melted more fully. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the non-transferred rotating arc plasma thermal spray gun of the utility model;

[0016] Figure 2 It is a partial structural schematic diagram of the non-transferred rotating arc plasma thermal spraying gun of the utility model;

[0017] Figure 3 It is a partial structural cross-sectional view of the non-transferred rotating arc plasma thermal spray gun of the utility model;

[0018] Figure 4 This is a metallographic photograph of the cross section of the chromium oxide coating produced by a conventional plasma spray gun;

[0019] Figure 5 This is a metallographic photograph of a cross section of a chromium oxide coating of a plasma thermal spraying gun of the utility model;

[0020] Figure 6 This is a metallographic photograph of a cross section of NiCr alloy sprayed by a conventional plasma spray gun;

[0021] Figure 7 This is a metallographic photograph of a cross section of NiCr alloy sprayed by the plasma thermal spray gun of the utility model.

[0022] In the figure: 1. spray gun body; 101. injection port; 102. guide rib; 103. circular limiting rib; 104. glue port; 105. feed port; 2. distribution ring; 201. spiral air distribution hole; 3. electromagnetic intervention block; 301. anode block; 4. conical cathode. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] like Figures 1 to 3 As shown, the utility model provides a technical solution: a non-transferred rotating arc plasma thermal spray gun, comprising: a spray gun body 1, the spray gun body 1 is equipped with a distribution ring 2, the spray gun body 1 is provided with an injection port 101, the distribution ring 2 is provided with a plurality of spiral air distribution holes 201, specifically 12 spiral air distribution holes 201 are used, a beam of gas from the air inlet is evenly distributed through the 12 spiral air distribution holes 201, so that the plasma gas of the spray gun is evenly distributed, and the angle of the straight gas passing through the small hole changes the gas flow direction, so that the gas forms a vortex rotating airflow in the chamber formed by the cathode and the anode.

[0025] An electromagnetic intervention block 3 is sleeved on the outside of the spray gun body 1, and the electromagnetic intervention block 3 is arranged between the distribution ring 2 and the injection port 101. A conical cathode 4 is arranged inside the spray gun body. The electromagnetic intervention block 3 is made up of 4 anode blocks 301 that are equally divided into 90° in the circumferential direction. The advantage of this is that if it is an integral anode, when the cathode and anode ionize the plasma gas to generate a discharge arc, the direction and position are uncertain and there is a certain randomness, which leads to arc instability. When a 4-split split anode is used, the position where the arc is generated by powering on the cathode and the cathode generally occurs at four splicing contact points, which not only makes the arc starting position controllable and the arc stable, but also allows the spray gun to increase the output power, so that the material is heated and melted more fully.

[0026] The outer surface of the spray gun body 1 is provided with a guide rib 102 for guiding the anode block 301. The outer surface of the spray gun body 1 is provided with a circular limiting rib 103 for matching with the anode block 301.

[0027] The contact surface between the outer surface of the spray gun body 1 and the anode block 301 is provided with a plurality of glue ports 104. The glue ports 104 are convenient for accumulating a large amount of adhesive, and the adhesive effect between the anode block 301 and the outer surface of the spray gun body 1 is improved through the glue ports 104, and the phenomenon of the anode block 301 falling off during operation is reduced.

[0028] A feed port 105 is provided on the outer surface of the conical cathode 4 and the spray gun body 1. The feed port 105 facilitates driving the powder material into the spray gun body 1. The material is heated and melted while flying in the plasma arc (flow). The molten droplets are finally sprayed on the substrate, cooled and stacked, and deposited to form coatings with various functions.

[0029] During operation, an inert gas (generally helium, argon, nitrogen, hydrogen, etc.) is driven into the spray gun body 1, and high-frequency direct current is passed between the anode and cathode. The high-frequency direct current ionizes the inert gas to form a plasma arc (flow) with a temperature as high as 10000K. Using inert gases such as nitrogen or argon, the powder material (metal, alloy, ceramic, etc.) to be prepared as a coating is sent into the plasma arc (flow). The material is heated and melted while flying in the plasma arc (flow), and the molten droplets are finally sprayed on the substrate, cooled and stacked, and deposited to form coatings with various functions.

[0030] like Figures 4 to 5 As shown, the porosity of the coating (chromium oxide ceramic) sprayed by the non-transferred rotating arc plasma thermal spray gun is significantly reduced compared to that of the conventional plasma spray gun, and the coating porosity is reduced from 5% to 2%. Due to the long heating time of the powder material and the sufficient heating, the coating hardness is increased from HV1057 to HV1178.

[0031] like Figure 6 to Figure 7 As shown, the spraying by the non-transferred rotating arc plasma thermal spray gun achieves more complete melting without a reduction in molten particles compared to the coating sprayed by the conventional plasma spray gun (nickel-chromium alloy, 80% nickel, 20% chromium).

[0032] The embodiments disclosed in the present utility model are preferred embodiments, but are not limited thereto. Ordinary technicians in this field can easily understand the spirit of the present utility model based on the above embodiments and make different extensions and changes. However, as long as they do not deviate from the spirit of the present utility model, they are all within the protection scope of the present utility model.

Claims

1. A non-transferred rotating arc plasma thermal spray gun, characterized in that: include: The spray gun body is equipped with a distribution ring, the spray gun body is provided with an injection port, the distribution ring is provided with a plurality of spiral air distribution holes, an electromagnetic intervention block is sleeved on the outer side of the spray gun body, and the electromagnetic intervention block is arranged between the distribution ring and the injection port.

2. The non-transferred rotating arc plasma thermal spray gun according to claim 1, characterized in that: The electromagnetic intervention block is formed by splicing four anode blocks equally divided into 90° in the circumferential direction.

3. The non-transferred rotating arc plasma thermal spray gun according to claim 2, characterized in that: The outer surface of the spray gun body is provided with guide ribs for guiding the anode block.

4. The non-transferred rotating arc plasma thermal spray gun according to claim 2, characterized in that: The outer surface of the spray gun body is provided with a circular limiting rib matched with the anode block.

5. The non-transferred rotating arc plasma thermal spray gun according to claim 2, characterized in that: The outer surface of the spray gun body and the contact surface of the anode block are provided with a plurality of glue openings.

6. The non-transferred rotating arc plasma thermal spray gun according to claim 1, characterized in that: The outer surface of the spray gun body is provided with a feed port.

7. The non-transferred rotating arc plasma thermal spray gun according to claim 1, characterized in that: A conical cathode is arranged inside the spray gun body.

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