CN-121976183-A - Powder feeding nozzle capable of efficiently cooling and inner hole cladding method

Abstract

The invention discloses a powder feeding nozzle capable of efficiently cooling and an inner hole cladding method, which comprises a nozzle body, wherein a laser beam channel is arranged on the nozzle body, a shielding gas channel is arranged outside the laser beam channel, and a plurality of powder feeding pipelines which are arranged around the laser beam channel are arranged on the nozzle body. The invention improves the cooling effect of the powder feeding nozzle, improves the reliability of the powder feeding nozzle, increases the upper limit of the bearable laser power, and is beneficial to reducing the miniaturization difficulty. In addition, the invention also provides a process method for cladding the inner hole of the thin-wall part, and a high-quality cladding layer can be quickly obtained.

Inventors

• ZHOU YICONG
• SHAO ZHONGKUI
• SHEN XIAOLI

Assignees

• 浙江省机电设计研究院有限公司

Dates

Publication Date

20260505

Application Date

20260202

Claims (9)

1. 1. The high-efficiency cooling powder feeding nozzle comprises a nozzle body, wherein a laser beam channel (1) is arranged on the nozzle body, a shielding gas channel (2) is arranged outside the laser beam channel (1), and a plurality of powder feeding pipelines (3) which are arranged around the laser beam channel (1) are arranged on the nozzle body, and the high-efficiency cooling powder feeding nozzle is characterized in that an inner water cooling cavity (6) is arranged between the laser beam channel (1) and the powder feeding pipelines (3), a cooling water inlet (5) and a cooling water outlet (4) are arranged on the inner water cooling cavity (6), and cooling water flows through the inner water cooling cavity (6) to cool an outlet area of the laser beam channel (1).
2. 2. The powder feeding nozzle with high efficiency cooling according to claim 1, wherein the laser beam channel (1), the inlet of the shielding gas channel (2) and the wall body forming the inner water cooling chamber (6) are integrated into a module unit, and the module unit is connected with the nozzle body in a detachable connection mode.
3. 3. The high-efficiency cooling powder feeding nozzle according to claim 1, wherein the powder feeding pipeline (3) is arranged on the nozzle body in a detachable connection mode, and the connecting part of the powder feeding pipeline (3) is positioned at one end far away from the powder outlet of the powder feeding pipeline (3).
4. 4. The efficient cooling powder feeding nozzle according to claim 1, wherein the powder feeding pipeline (3) is of a straight pipe structure, the number of the powder feeding pipelines is 4, the powder feeding pipelines are uniformly and symmetrically arranged, and the included angle between the axis of each powder feeding pipeline and the horizontal direction is not smaller than 60 degrees.
5. 5. The efficient cooling powder feeding nozzle according to claim 1, wherein fin-type heat dissipation structures (13) are arranged in the inner water cooling cavity (6), and the fin-type heat dissipation structures (13) are a plurality of disc-shaped structures which are arranged at intervals along the axial direction of the cavity.
6. 6. The powder feeding nozzle with high-efficiency cooling according to claim 1, wherein the number of the cooling water inlets (5) and the cooling water outlets (4) is two, and the cooling water inlets and the cooling water outlets are symmetrically arranged at the upper part and the lower part of the cavity respectively so as to increase the flow rate and the flow velocity of cooling water and enhance the heat exchange effect.
7. 7. The high-efficiency cooling powder feeding nozzle according to claim 1, wherein the inner water cooling chamber (6) is divided into an upper cavity and a lower cavity, the lower cavity is a gradual change type cavity covering the outlet area of the laser beam channel (1), cooling water enters the lower cavity from the water inlet (5), flows into the upper cavity through the water through holes (10), and is discharged from the water outlet (4).
8. 8. A method for cladding an inner hole of a thin-wall workpiece by using the high-efficiency cooling powder feeding nozzle as claimed in any one of claims 1 to 7, which is characterized by comprising the following steps: The powder feeding nozzle is vertically arranged in an inner hole of the thin-wall workpiece, and the distance between the end face of the nozzle and the inner wall of the workpiece is controlled to be 15-19mm; The laser power is 1300-3000W, the cladding linear speed is 50-180mm/s, and the powder feeding speed is 5-15g/min; And the laser power, the cladding linear speed and the powder feeding rate meet the following empirical relation: ; ; wherein: For the laser power to be high, In order to achieve the speed of the cladding line, Is the powder feeding rate.
9. 9. The method for cladding the inner hole according to claim 8, wherein the diameter of the laser spot is 2-2.5mm, the wall thickness of the workpiece is 2-3mm, and protective gas is continuously introduced through the protective gas channel (2) in the cladding process, so that dust is prevented from polluting a laser lens or interfering with a light path.

Description

Powder feeding nozzle capable of efficiently cooling and inner hole cladding method Technical Field The invention relates to the technical field of laser cladding, in particular to a powder feeding nozzle capable of efficiently cooling and an inner hole cladding method. Background The laser cladding is carried out by heating by high-density laser, the cladding powder or wire material is sprayed into a molten pool through a nozzle and is melted with the surface of a base material to form a compact metallurgical bonding layer, and the compact metallurgical bonding layer is piled layer by layer in a region needing surface modification or repair, so that the aim of improving the surface performance or repair is fulfilled, and the method is widely applied to the fields of aerospace, automobile industry, mechanical manufacturing and the like at present and has wide application prospect. The laser cladding powder feeding nozzle is used as one of key parts in laser cladding application, and determines the stability of powder conveying and the form of a powder beam, so that the design quality of the nozzle can directly influence the coupling effect of powder and laser, and further determines the cladding effect. When the laser is emitted, the central outlet of the nozzle is tightly attached to the laser beam, so that a large amount of heat can be absorbed, and if the heat cannot be timely emitted, the nozzle can be deformed, and the laser cladding quality is seriously affected due to unstable laser output. At present, aiming at a high-power laser cladding powder feeding nozzle, a cooling cavity in a main flow nozzle structure is positioned at the outer side of a powder feeding channel or at a position far away from the outlet of the center of the nozzle, the cooling position is far away from the heat absorption position of the nozzle, and the heat dissipation effect is poor, so that the upper limit of the laser power bearable by the nozzle is limited, and the reliability of the powder feeding nozzle is also influenced. In addition, compared with the laser channel outlet, the diameter of the powder feeding channel outlet is small, when the powder feeding nozzle is overheated, powder melting is extremely easy to occur, so that the powder feeding channel is blocked, even the powder feeding channel is deformed, and the powder conveying is unstable. At present, most commercial powder delivery nozzles are inconvenient in the case of being incapable of being disassembled in a modularized mode or being disassembled, and when the problems occur, the whole powder delivery nozzle can be replaced only, so that larger waste of materials and funds can be brought. Meanwhile, in order to ensure the cooling effect, the commercial powder feeding nozzle often adopts a larger cooling water cavity structure, which leads to larger size and weight of the powder feeding nozzle and increases material cost and cost of a matched motion mechanism, while part of commercial small powder feeding nozzles reduce the volume and the mass of the powder feeding nozzle, but limit the upper limit of laser power which can be born by the nozzle due to the weakening of the cooling effect, and are difficult to meet the increasingly increased process requirements in practical application. The former needs to use high-power laser in the application fields of ultra-high-speed laser cladding and inner hole cladding, and the latter has high requirements on the miniaturization of the powder feeding nozzle, and the cooling capacity of the powder feeding nozzle is extremely high under the two applications. Moreover, due to the problem of structural design, the cooling water cavity of the commercial powder feeding nozzle is difficult to completely cover the main heat absorption area of the laser beam channel, so that the cooling effect is reduced on one hand, and on the other hand, local overheating is extremely easy to cause and deform. In the prior art of publication No. CN 215668210U, a structure of a conventionally sized annular powder feeding nozzle is described, in which a water cooling cavity is located outside the powder feeding cavity, and the water cooling cavity only covers the middle section of the heat absorbing area of the powder feeding nozzle, and at the same time, the volume of the water cooling cavity is smaller, and no other heat dissipation structure is designed. In addition, the structural design can not isolate the heat absorption area and the powder feeding pipeline, and meanwhile, the water outlet and the water inlet of the powder feeding pipeline are designed to be one inlet and one outlet, so that the cooling effect is common, and the miniaturized powder feeding nozzle and the high laser power scene are difficult to deal with. The prior art of publication No. CN111139470 a describes a structure of a two-material powder feeding nozzle, in which the cooling chamber is located at an upper position of the powder feeding nozzle, further from the