Annular hollow offset-focus laser cladding device

Abstract

The invention discloses an annular hollow offset-focus laser cladding device, and relates to the technical field of laser processing. The annular hollow offset-focus laser cladding device comprises a shell, a conical reflector, an annular off-axis parabolic focus lens, a nozzle and a powder spraying pipe, the top of the shell is provided with a light inlet, the conical reflector is arranged in the shell, and the conical reflector is arranged facing the light inlet; the annular off-axis parabolic focus lens and the conical reflector are oppositely and coaxially arranged; and the nozzle is installed below the conical reflector, the lower end of the nozzle is connected with the powder spraying pipe, the powder spraying pipe is coaxial with annular hollow offset-focus light formed after reflection of the annular off-axis parabolic focus lens, and a collimation protection gas sleeve is arranged on the periphery of the powder spraying pipe. The annular off-axis parabolic focus lens is used for horizontally shifting the focusing focus of the maternal parabola. According to the annular hollow offset-focus laser cladding device, the homogenization of the energy density of an annular light spot is realized, the coupling effect of a laser beam and powder is improved, the utilization rate of the metal powder is improved, and the cladding quality and appearance are improved.

Description

technical field [0001] The invention relates to the technical field of laser processing, in particular to an annular hollow defocused laser cladding device. Background technique [0002] Laser cladding technology is an advanced manufacturing technology combining laser technology and additive manufacturing technology, which has developed rapidly in recent years. As an advanced processing and forming technology, it is widely used in metal 3D printing, surface modification of materials and repair of failed parts, etc., which solves many problems in engineering practice and creates huge economic benefits in engineering applications. Laser cladding equipment mainly includes lasers, cladding nozzles, processing platforms and feeding devices. The laser cladding nozzle is the key core component of the laser cladding system, which can realize the transmission, transformation, focusing and synchronous delivery of the cladding material of the laser beam, and realize the precise coupli...

AI Technical Summary

Problems solved by technology

[0014] 3) The powder particles are seriously insufficiently heated, even without melting, they are still solid particles,

[0016] At the same time, the conventional laser cladding rate is low, generally 0.5-3m / min, the powder utilization rate is low, generally about 60%, and the cladding layer is rough, resulting in serious waste of materials, and the laser energy is focused on the base material. The powder is mixed and combined by melting the matrix material, which makes the laser energy utilization efficiency and cladding rate low, and the energy absorbed by the powder center is not enough under the large defocus, so that the powder is still solid particles when combined with the matrix material, and the surface of the finished product is smooth. degree difference

In order to improve the cladding efficiency, by increasing the laser power and increasing the spot area, but it will lead to an increase in the deformation of the workpiece, it is necessary to reserve a larger machining reserve;

[0017] When using a non-defocused laser cladding nozzle with internal powder feeding and trying to carry out wide-spot cladding under a large defocus, the duty cycle of the ring-shaped spot on the working plane becomes larger, resulting in insufficient light energy in the middle of the molten pool. The high-density powder ejected from the powder pipe on the central axis falls into the hollow area of ​​the light spot and cannot be fully melted, so under-melting, powder sticking, holes, etc. will easily occur, causing adhesion defects between the cladding layer and the substrate. The morphology of the cladding layer is not full, resulting in the failure of cladding accumulation

That is, the non-defocused annular hollow laser cannot achieve high-efficiency wide-channel cladding forming by changing the defocus amount

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