Coaxial powder feeding device and powder feeding method for broadband laser cladding

Abstract

The invention relates to a coaxial powder feeding device for broadband laser cladding and a powder feeding method thereof. The device comprises a sleeve module; a light beam isolation cover, and an inner-layer air cover, an outer-layer air cover and a cooling water cover for coating the light beam isolation cover in sequence from inside to outside are arranged at the bottom end of the sleeve module; two powder feeding pipes symmetrically arranged about the light beam isolation cover are arranged between the inner-layer air cover and the outer-layer air cover at the bottom end of the sleeve module; outlets of the powder feeding pipes are rectangular pipes; outlets of the light beam isolation cover, the inner-layer air cover, the outer-layer air cover and the cooling water cover at the bottoms are rectangular; and the sleeve module is provided with a water injecting port, a water outlet, an outer-layer protective gas inlet, an inner-layer protective gas inlet and a powder feeding inlet. The method comprises three steps of connection of external source equipment, powder feeding device parameter adjustment and coaxial broadband powder feeding laser cladding. The device can prevent fused metal liquid from splashing to block the outlet of the powder feeding device, can enable the powder spot pavement to become more uniform in powder spot shaping, and is simple in structure and easy to machine.

Description

technical field [0001] The invention belongs to the technical field of surface engineering, and in particular relates to a coaxial powder feeding device for broadband laser cladding and a powder feeding method thereof. Background technique [0002] Laser cladding is an advanced surface treatment technology. Its principle is to use laser to irradiate the alloy powder and the surface of the substrate to melt it, and after rapid solidification, a coating with good metallurgical bonding is formed to improve the wear resistance of the surface of the substrate material. Compared with traditional surface treatment processes such as thermal spraying, arc surfacing, plasma spraying, etc., laser cladding has many advantages such as small heat-affected zone, small deformation, low dilution rate and controllable area. Advantages, it is widely used in the remanufacturing and repairing of steam turbine blades, crankshafts, machine tool spindles and other components. [0003] With the inc...

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Problems solved by technology

[0003] With the increasing demand for surface repair of large shafts (such as marine crankshafts, hydraulic cylinder columns, etc.), traditional laser cladding equipment with small spots cannot meet the repair efficiency of large shafts due to low cladding efficiency. The urgent need for large-spot broadband laser cladding equipment came into being. The problem brought about by this is how to accurately and evenly transport the alloy powder to the molten pool generated by laser cladding during the laser cladding process. The existing coaxial conveyor Powder nozzles are mostly suitable for circular or square light spots, but not for large broadband rectangular light spots

[0004] Many domestic scholars have carried out a series of designs on the powder feeding device for broadband laser cladding. The invention patent "a lateral powder feeding nozzle device for laser cladding" with the authorization number CN103132072B proposes a lateral powder feeding nozzle suitable for rectangular spot. Powder feeding nozzle, this kind of lateral powder feeding nozzle device is sensitive to the direction of laser cladding, and cannot solve the directional problem caused by forward and reverse powder feeding, and the powder aggregation is poor; the invention patent with application number 201510808637.8 "a broadband "Laser cladding system and its powder feeding nozzle" discloses a system and powder feeding nozzle suitable for broadband laser cladding. This adjustable broadband powder feeding system is complex, difficult to control, and the powder uniformity is poor. Directly into the molten pool; the invention patent of CN1319459A "adjustable broadband bidirectional symmetrical powder feeding laser cladding nozzle" proposes a coaxial broadband laser cladding powder feeding nozzle. The powder feeding head with a rectangular channel is installed on the side to realize the coaxial conveying of the rectangular powder beam. This kind of coaxial powder feeding nozzle is difficult to process, and the powder beam is unevenly laid and the processing quality is poor.

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