CN112553620B - A gas protective cover device for laser cladding coaxial powder feeding gun - Google Patents

Abstract

The invention discloses a gas protection cover device for a laser cladding coaxial powder feeding gun, which relates to the technical field of laser material processing and comprises a protection cover shell, a protection cover inner core and a porous copper strip, wherein the protection cover shell is sleeved on the outer side of the protection cover inner core, and the porous copper strip is arranged at the lower end of the protection cover shell; a first cavity chamber is formed by the inner side surface of the protective cover shell, the outer side surface of the protective cover inner core and the upper surface of the porous copper plate strip; one end of the first cavity chamber is communicated with the outer side face of the protective cover shell through a first through hole, and the other end of the first cavity chamber is communicated with the lower surface of the porous copper plate strip through the porous copper plate strip; the porous copper strip is configured to slow the flow rate of a gas stream penetrating the porous copper strip. By implementing the method, the solidified cladding layer can be protected from being oxidized, the airflow of the protective gas layer can be optimized, the oxygen brought by the gas turbulence is reduced, and the oxidation of the coating is avoided.

Description

A gas protective cover device for laser cladding coaxial powder feeding gun

technical field

The invention relates to the technical field of laser material processing, in particular to a gas protection cover device for a coaxial powder feeding gun for laser cladding.

Background technique

Laser cladding is a surface modification technology. External materials are added to the molten pool formed by the laser irradiation of the matrix by synchronizing or presetting materials, and the two are co-solidified to form a very low dilution and A surface coating that is metallurgically combined with the base material, thereby significantly improving the wear resistance, corrosion resistance, heat resistance, oxidation resistance and electrical properties of the base material surface; in the process of laser cladding, in order to avoid or reduce coating oxidation , the main method is to blow inert gas into the laser molten pool, so that the molten metal is out of contact with the oxygen in the air, so as to protect the molten metal from being oxidized.

In the prior art, the common feature of the laser cladding coaxial powder feeding gun device is that the inert gas with air pressure is used, and the alloy powder is transported through the conical powder feeding channel and then collected at a point in front of the nozzle. A shielding gas for the powder or an outer shielding gas surrounding the alloy powder protects the alloy powder from oxidation. Due to the laser cladding alloy layer, especially the easily oxidized coating materials, such as iron-based, titanium-based, aluminum-based, etc., it takes a long time from solidification to cooling to 500 ° C. During this period, the cladding coating will Oxidation occurs. The coaxial powder feeding gun and its outer protective gas described in the prior art can protect the alloy melt in the laser molten pool, but cannot guarantee that the solidified cladding layer will not be oxidized. In addition, the shielding gas conveying device in the prior art has a large shielding gas flow rate, which will cause turbulent flow in the laser molten pool and entrain air, thereby forming an inert shielding gas layer containing oxygen. Even if the shielding gas flow rate is increased, the Coating oxidation problems are difficult to avoid.

Therefore, those skilled in the art are devoted to developing a gas shield device for laser cladding coaxial powder feeding gun, which can not only protect the solidified cladding layer from being oxidized, but also optimize the airflow of the inert protective gas layer and reduce the gas Turbulence brings in oxygen and avoids oxidation of the coating.

SUMMARY OF THE INVENTION

In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is that the prior art cannot avoid oxidation of the solidified cladding layer, and air is involved in the formation of the inert protective gas layer, causing the coating to oxidize.

In order to achieve the above purpose, the present invention provides a gas protective cover device for a laser cladding coaxial powder feeding gun, which includes a protective cover shell, a protective cover inner core, and a porous copper strip, and the protective cover shell is sleeved at the place. Outside the inner core of the protective cover, the porous copper strip is arranged at the lower end of the protective cover shell, and the protective cover shell is provided with a first through hole;

The inner side of the protective cover shell, the outer side of the inner core of the protective cover and the upper surface of the porous copper strip form a first cavity; one end of the first cavity is set to pass through the first through hole communicated with the outer surface of the protective cover shell, and the other end of the first cavity is communicated with the lower surface of the porous copper strip through the porous copper strip; the perforated copper strip is configured to slow down penetration of the Air flow rate of porous copper lath.

Further, the porous copper strip is provided with a plurality of second through holes, and the second through holes communicate with the upper surface of the porous copper strip and the lower surface of the porous copper strip.

Further, a plurality of the second through holes are evenly distributed on the porous copper strip.

Further, the diameters of several of the second through holes are the same.

Further, the cross-sectional shape of the porous copper strip is T-shaped, and the center line of the porous copper strip intersects the center axis of the inner core of the protective cover.

Further, the protective cover shell further includes a cooling hole and a third through hole, the cooling hole is arranged inside the protective cover shell, and the cooling hole is arranged to pass through the third through hole and the cooling hole. The outer side surface of the protective cover shell is communicated.

Further, the cooling holes are arranged along the circumferential direction of the protective cover shell.

Further, the number of the third through holes is 2, and two of the third through holes are arranged on both sides of the protective cover shell.

Further, the inner core of the protective cover further includes a fourth through hole, the central axis of the fourth through hole coincides with the central axis of the inner core of the protective cover, and the fourth through hole further includes a first conical surface, The first conical surface is disposed on the upper part of the fourth through hole, and the first conical surface is configured to be able to fit with the outer conical surface of the nozzle of the coaxial powder feeding gun.

Further, the inner core of the protective cover further includes a second conical surface, and the second conical surface is disposed on the lower part of the outer side surface of the inner core of the protective cover.

Further, it also includes a first pipe joint and a second pipe joint, the first pipe joint is threadedly connected to the first through hole, and the second pipe joint is threadedly sealed to the third through hole.

In the present invention, the threaded sealing connection means that the connection is fastened and sealed with each other by means of threads.

Compared with the prior art, through the implementation of the present invention, at least the following beneficial technical effects are obtained:

(1) The technical solution disclosed in the present invention can form a gentle and stable protective gas layer on the surface of the cladding coating, can effectively protect the cladding coating, and can effectively avoid the oxidation of the cladding layer, and can also avoid the solidification after solidification. Oxidation of the coating.

(2) The technical solution disclosed in the present invention can realize large-area and high-quality laser cladding of easily oxidized titanium, aluminum and magnesium alloys.

(3) The technical solution disclosed in the present invention has the advantages of simple structure, convenient loading and unloading, and easy popularization.

The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, characteristics and effects of the present invention.

Description of drawings

1 is a schematic structural diagram of a gas shield device for a laser cladding coaxial powder feeding gun according to a preferred embodiment of the present invention;

Fig. 2 is the A-direction view structural schematic diagram of the embodiment shown in Fig. 1;

Fig. 3 is the left-hand side view structural schematic diagram of the embodiment shown in Fig. 1;

4 is a schematic structural diagram of the laser cladding process of the coaxial powder feeding gun used in the prior art;

Fig. 5 is the result diagram of adopting the TC4 titanium alloy of laser cladding of the device shown in Fig. 4;

Fig. 6 is the structural representation that adopts the embodiment shown in Fig. 1 to be installed on the coaxial powder feeding gun;

FIG. 7 is a graph showing the results of laser cladding of TC4 titanium alloy using the device shown in FIG. 6 .

Among them, 1- laser beam, 2- coaxial powder feeding gun for laser cladding, 3- outer cone surface of coaxial powder feeding gun nozzle, 4- laser cladding powder, 5- laser cladding coating, 6- gas protection Cover device, 61-protective cover shell, 62-protective cover inner core, 63-first pipe joint, 64-second pipe joint, 65-cooling hole, 66-porous copper strip, 67-first cavity, 7-Inert protective gas, 8-Laser cladding substrate, 91-Laser cladding direction, 92-Laser molten pool, 93-Coating high temperature section, 94-Coating low temperature section.

Detailed ways

The following describes several preferred embodiments of the present invention with reference to the accompanying drawings, so as to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned herein.

In the drawings, structurally identical components are denoted by the same numerals, and structurally or functionally similar components are denoted by like numerals throughout. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thicknesses of components are appropriately exaggerated in some places in the drawings.

In the description of the embodiments of the present application, it should be clear that the terms "center", "middle", "upper", "lower", "left", "right", "inner", "outer", "top", " The orientation or positional relationship indicated by "bottom", "side", "vertical", "horizontal", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating Or imply that the described device or element must have a specific direction or positional relationship, that is, it cannot be construed as a limitation on the embodiments of the present application; in addition, the terms "first", "second", "third", "fourth" etc. are only used to facilitate or simplify the description, not to indicate or imply their importance.

As shown in FIG. 1 , this embodiment provides a gas shield device 6 for a laser cladding coaxial powder feeding gun, including a shield shell 61 , a shield inner core 62 , a porous copper strip 66 , and a first pipe joint 63. The second pipe joint 64, the protective cover shell 61 is sleeved on the outer side of the protective cover inner core 62, the porous copper strip 66 is arranged on the lower end of the protective cover shell 61, and the protective cover shell 61 is provided with a first through hole. In the embodiment, it is preferable to set a first through hole on both sides of the protective cover shell 61; The upper end of the first cavity 67 is communicated with the outer side of the protective cover shell 61 through the first through hole, one end of the first pipe joint 63 is threadedly connected with the first through hole, and the other end of the first pipe joint 63 is connected with the hose In another embodiment of the present invention, one end of the first pipe joint 63 is sealed with the first through hole by welding or pasting; Communication; the perforated copper strip 66 is configured to slow down the flow rate of airflow penetrating the perforated copper strip 66 , and the first cavity 67 preferably communicates with the outside only through the first through hole and the perforated copper strip 66 .

In this embodiment, the protective gas is passed through the hose connected to the first through hole, the protective gas enters the first hollow chamber 67 through the first through hole, and the protective gas enters the first hollow chamber 67 through the relaxation of the first hollow chamber 67 After an empty chamber 67 , the speed becomes gentle. As the pressure of the shielding gas in the first empty chamber 67 gradually increases, the shielding gas in the first empty chamber 67 gradually penetrates out of the first empty chamber through the porous copper strips 66 . 67. According to the shape of the laser cladding working area, the shape and setting range of the porous copper strip can be reasonably set, so as to form a gentle and stable protective gas layer on the surface of the laser cladding coating 5; in this embodiment, the protective gas is an inert gas , preferably argon.

In this embodiment, the porous copper strip 66 is provided with a plurality of second through holes, the second through holes communicate with the upper surface of the porous copper strip 66 and the lower surface of the porous copper strip 66 , and the second through holes are on the porous copper strip 66 . Evenly distributed.

In one embodiment of the present invention, each second through hole has the same diameter, and the cross-sectional shape of the second through hole is a circle, a polygon, an ellipse or an oblong hole.

In this embodiment, the cross-sectional shape of the porous copper strip 66 is T-shaped, the lower end of the protective cover shell 61 is provided with a T-shaped groove, and the porous copper strip 66 is fixedly installed in the T-shaped groove at the lower end of the protective cover shell 61; The centerline of the strip 66 intersects the centerline of the shroud core 62 as shown in FIG. 2 .

The protective cover shell 61 further includes a cooling hole 65 and a third through hole. The cooling hole 65 is disposed inside the protective cover shell 61 , the number of the third through holes is 2, and two third through holes are disposed in the protective cover shell 61 . On both sides, the cooling holes 65 are arranged to communicate with the outer surface of the protective cover case 61 through the third through holes, and the cooling holes 65 are arranged along the circumferential direction of the protective cover case 61 .

As shown in FIG. 2 , the cooling hole 65 is a circular hole used for cooling the protective cover shell 61 , one end of the second pipe joint 64 is threadedly connected to the third through hole, and the other end of the second pipe joint 64 is connected to the cooling hose In another embodiment of the present invention, one end of the second pipe joint 64 is sealed with the third through hole by welding or pasting; as shown in FIG. 3 , the second pipe joint 64 is arranged directly below the first pipe joint 63 , the porous copper strip 66 is arranged below the second pipe joint 64 .

In this embodiment, the cooling medium is passed through the hose connected to the third through hole, the cooling medium enters the cooling hole 65 through the third through hole on one side, and the cooling medium in the cooling hole 65 passes through the third through hole on the other side. The hole flows out, and the cooling medium flows through the inside of the protective cover shell 61 to cool the protective cover shell 61 or adjust its temperature, so that the heat dissipation of the protective cover shell 61 and the porous copper strips 66 can be realized, so that the gas protective cover device 6 It can work for a long time; in this embodiment, the cooling medium is preferably water, more preferably soft water. In this embodiment, soft water refers to water that does not contain or contains less soluble calcium and magnesium compounds, and the content of calcium salt and magnesium salt in the soft water is 1.0-50 mg/L.

As shown in FIG. 1 , the inner core 62 of the protective cover further includes a fourth through hole, the central axis of the fourth through hole coincides with the central axis of the inner core 62 of the protective cover, the fourth through hole further includes a first conical surface, and the first conical surface Set on the upper part of the fourth through hole, the first conical surface is configured to fit with the outer conical surface 3 of the coaxial powder feeding gun nozzle; the inner core 62 of the protective cover also includes a second conical surface, and the second conical surface is arranged on the protective cover The lower part of the outer surface of the inner core 62 is provided with a second conical surface, so that the first cavity 67 is as close as possible to the central axis of the fourth through hole.

As shown in FIG. 4 , the laser beam 1 passes through the coaxial powder feeding gun 2 for laser cladding, melts the laser cladding powder 4, and forms a laser cladding coating 5 on the laser cladding substrate 8; The coating 5 has three temperature sections, namely the laser melting pool 92, the coating high temperature section 93, and the coating low temperature section 94. The temperature of the laser melting pool 92 is greater than or equal to 1500°C, and the temperature of the coating high temperature section 93 is 500°C to 1500°C. The temperature of the low temperature section 94 of the coating is from room temperature to 500°C; as shown in Figure 5, the actual laser cladding TC4 titanium alloy is used for laser cladding. The high temperature section 93 of the coating layer cannot be effectively protected by the protective gas and is oxidized, and the coating of the high temperature section 93 of the coating layer exhibits a blue oxidation color.

As shown in FIG. 6 , the gas shield device 6 is installed on the coaxial powder feeding gun 2 for laser cladding, and the first conical surface of the inner core 62 of the protective shield is fitted with the outer conical surface 3 of the coaxial powder feeding gun nozzle. The laser beam 1 passes through the coaxial powder feeding gun 2 for laser cladding, melts the laser cladding powder 4, and forms a laser cladding coating 5 on the laser cladding substrate 8; the inert protective gas is connected through the first pipe joint 63 Argon gas enters the first cavity 67 through the protective gas channel, and continues to pass through the porous copper strip 66 after the first cavity 67 is sedated, forming a gentle and stable argon on the surface of the laser cladding coating 5 The inert protective gas 7 of the gas can effectively protect the laser cladding coating 5 and avoid oxidation of the high temperature section 93 of the coating after solidification. As shown in Figure 7, the actual laser cladding TC4 titanium alloy is used. The coaxial powder feeding gun 2 for laser cladding is equipped with a gas protective cover device 6. The high temperature section 93 of the TC4 titanium alloy coating is effectively protected by the protective gas, and the coating has a high temperature. The coating of segment 93 appears silvery white.

The coaxial powder feeding gun 2 for laser cladding using the gas shield device 6 disclosed in this embodiment can obtain a uniform laser cladding layer on the metal surface after laser irradiation, which not only greatly improves the efficiency of laser cladding, but also The cladding layer has less defects such as oxidation, and is suitable for large-area laser cladding treatment of easily oxidizable alloys such as titanium, aluminum, and magnesium. The preferred embodiments of the present invention have been described in detail above. It should be understood that many modifications and changes can be made according to the concept of the present invention by those skilled in the art without creative efforts. Therefore, any technical solutions that can be obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the prior art according to the concept of the present invention shall fall within the protection scope determined by the claims.

Claims (5)

1. a laser cladding coaxial powder gun gas protective cover device, is characterized in that, comprises protective cover shell, protective cover inner core, porous copper strip, described protective cover shell is sleeved on described protective cover On the outside of the inner core, the porous copper strip is arranged at the lower end of the protective cover shell, and the protective cover shell is provided with a first through hole; The inner side of the protective cover shell, the outer side of the inner core of the protective cover and the upper surface of the porous copper strip form a first cavity; one end of the first cavity is set to pass through the first through hole communicated with the outer surface of the protective cover shell, and the other end of the first cavity is communicated with the lower surface of the porous copper strip through the porous copper strip; the perforated copper strip is configured to slow down penetration of the The air flow rate of the porous copper strip; The porous copper strip is provided with a plurality of second through holes, and the second through holes communicate with the upper surface of the porous copper strip and the lower surface of the porous copper strip; A plurality of the second through holes are evenly distributed on the porous copper strip; The protective cover shell further includes a cooling hole and a third through hole, the cooling hole is arranged inside the protective cover shell, and the cooling hole is arranged to pass through the third through hole and the protective cover shell External and lateral communication; The inner core of the protective cover further includes a fourth through hole, the central axis of the fourth through hole coincides with the central axis of the inner core of the protective cover, the fourth through hole further includes a first conical surface, the A conical surface is disposed on the upper part of the fourth through hole, and the first conical surface is configured to fit with the outer conical surface of the coaxial powder feeding gun nozzle; The inner core of the protective cover further includes a second conical surface, and the second conical surface is arranged on the lower part of the outer side surface of the inner core of the protective cover. 2 . The gas shield device according to claim 1 , wherein the cross-sectional shape of the porous copper strip is T-shape, and the center line of the porous copper strip intersects the central axis of the inner core of the shield. 3 . 3 . The gas shield device according to claim 1 , wherein the cooling holes are arranged along the circumferential direction of the shield shell. 4 . 4 . The gas shield device according to claim 1 , wherein the number of the third through holes is 2, and two of the third through holes are provided on both sides of the shield shell. 5 . 5 . The gas shield device according to claim 1 , further comprising a first pipe joint and a second pipe joint, the first pipe joint is threadedly connected to the first through hole, and the first pipe joint is threaded and sealed. 6 . The second pipe joint is threadedly connected with the third through hole.

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