阅读说明：本技术 利用激光调制高深径比孔内表面特征的方法 (Method for modulating surface characteristics in hole with high depth-diameter ratio by using laser ) 是由 王志文 郑宏宇 丛建臣 于 2019-10-10 设计创作，主要内容包括：利用激光调制高深径比孔内表面特征的方法,属于激光加工技术领域。其特征在于：包括以下步骤：(1)清洗孔内表面；(2)装夹,使得孔轴线与激光正入射方向重合；(3)将激光入射角度偏转,并沿孔内表面周期循环扫描；(4)调整光束相对于工件表面的距离；(5)使得光束覆盖整个孔内表面。本发明基于激光重熔技术,采用激光对高深径比孔进行再加工。通过激光熔融一薄层材料的方式高效消除局部纹路、局部微裂纹。极大减小了表面粗糙度,并消除了表面微裂纹。具有高精度、高效率的特点,可以实现流水线生产。(A method for modulating the surface characteristics of a hole with high depth-diameter ratio by using laser belongs to the technical field of laser processing. The method is characterized in that: the method comprises the following steps: (1) cleaning the inner surface of the hole; (2) clamping to enable the axis of the hole to coincide with the normal incidence direction of the laser; (3) deflecting the incident angle of the laser and periodically and circularly scanning along the inner surface of the hole; (4) adjusting the distance of the beam relative to the surface of the workpiece; (5) so that the beam covers the entire inner surface of the hole. The invention is based on the laser remelting technology, and the laser is adopted to reprocess the hole with high depth-diameter ratio. Local lines and local microcracks are effectively eliminated in a mode of melting a thin layer material by laser. The surface roughness is greatly reduced and surface microcracks are eliminated. The method has the characteristics of high precision and high efficiency, and can realize flow line production.)

1. A method for modulating the surface characteristics in a hole with a high depth-diameter ratio by using laser is characterized by comprising the following steps: the method comprises the following steps:

(1) cleaning the inner surface of the hole to remove impurities;

(2) clamping the workpiece to enable the axis of the hole to be coincident with the normal incidence direction of the laser;

(3) adjusting laser parameters, deflecting the laser incidence angle by using a laser (1), and periodically and circularly scanning along the inner surface of the hole;

(4) adjusting the distance of the light beam relative to the surface of the workpiece, so that the light beam rotates around the inner surface of the hole and moves up and down relative to the inner surface of the hole;

(5) depending on the nature of the optical transmission, the beam is caused to cover the entire inner surface of the hole by multiple reflections.

2. The method of claim 1 for modulating surface features in a high depth to diameter ratio hole using a laser, wherein: the hole is a through hole, a reflector is arranged below the hole, and the laser is reflected back into the hole through the reflector.

3. The method of claim 1 for modulating surface features in a high depth to diameter ratio hole using a laser, wherein: and (3) forming an included angle between the axis of the hole and the outer surface in the step (2) as a vertical angle or an inclined angle.

4. The method of claim 1 for modulating surface features in a high depth to diameter ratio hole using a laser, wherein: the material of the holes in the step (1) can be steel material, metal material, semiconductor material or ceramic material.

5. The method of claim 1 for modulating surface features in a high depth to diameter ratio hole using a laser, wherein: the laser in the step (2) may be a continuous laser or a pulsed laser.

6. The method of claim 1 for modulating surface features in a high depth to diameter ratio hole using a laser, wherein: and (3) melting the laser energy in the step (2) on the surface of the hole or increasing the surface temperature by more than 300 ℃.

7. The method of claim 2 for modulating surface features in a high depth to diameter ratio hole using a laser, wherein: the reflector is a plane reflector or a curved reflector.

Technical Field

A method for modulating the surface characteristics of a hole with high depth-diameter ratio by using laser belongs to the technical field of laser processing.

Background

The processing of the deep hole with the high depth-diameter ratio is a difficult processing technology and a key technology of machining all the time, and is a bottleneck process of a production line. The fine processing of high depth-diameter ratio and small aperture provides a severe test for the traditional mechanical processing. The elongated holes are usually obtained by a drilling process, and machining lines are left on the inner wall of the elongated holes and microcracks exist. Fatigue cracks can be generated under the action of alternating load, and the overall service life of workpieces such as crankshafts is greatly reduced.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method for modulating the characteristics of the inner surface of the hole with the high depth-diameter ratio by using the laser overcomes the defects of the prior art and provides a method for modulating the characteristics of the inner surface of the hole with the high depth-diameter ratio by using the laser, which is based on a laser remelting technology, eliminates the mechanical stress generated by machining the hole, and effectively removes machining lines left on the inner surface of the hole by machining.

The technical scheme adopted by the invention for solving the technical problem is a method for modulating the surface characteristics in a hole with high depth-diameter ratio by using laser, which is characterized by comprising the following steps: the method comprises the following steps:

(1) cleaning the inner surface of the hole to remove impurities;

(2) clamping the workpiece to enable the axis of the hole to be coincident with the normal incidence direction of the laser;

(3) adjusting laser parameters, deflecting the laser incidence angle through a laser, and periodically and circularly scanning along the inner surface of the hole;

(4) adjusting the distance of the light beam relative to the surface of the workpiece, so that the light beam rotates around the inner surface of the hole and moves up and down relative to the inner surface of the hole;

(5) depending on the nature of the optical transmission, the beam is caused to cover the entire inner surface of the hole by multiple reflections.

The invention is based on the laser remelting technology, and the laser is adopted to reprocess the hole with high depth-diameter ratio. Local lines and local microcracks are effectively eliminated in a mode of melting a thin layer material by laser. The surface roughness is greatly reduced and surface microcracks are eliminated. Based on the laser remelting technology, the inner surface of the hole is reprocessed by melting and then solidifying the material of the whole inner surface of the hole. The machining method has the characteristics of high precision and high efficiency, has the advantages of high automation, high controllability and the like, and can realize flow line production.

The hole is a through hole, a reflector is arranged below the hole, and the laser is reflected back into the hole through the reflector.

And (2) forming an included angle between the axis of the hole and the outer surface in the step (1) as a vertical angle or an inclined angle.

The pore material in the step (1) can be a steel material, a metal material, a semiconductor material or a ceramic material.

The laser in the step (2) may be a continuous laser or a pulsed laser.

And (3) melting the laser energy in the step (2) on the surface of the hole or increasing the surface temperature by more than 300 ℃.

And (4) melting the hole material by using the laser in the step (3).

The reflector is a plane reflector or a curved reflector.

Compared with the prior art, the invention has the beneficial effects that:

the invention is based on the laser remelting technology, and the laser is adopted to reprocess the hole with high depth-diameter ratio. Local lines and local microcracks are effectively eliminated in a mode of melting a thin layer material by laser. The surface roughness is greatly reduced and surface microcracks are eliminated. Based on the laser remelting technology, the inner surface of the hole is reprocessed by melting and then solidifying the material of the whole inner surface of the hole. The machining method has the characteristics of high precision and high efficiency, has the advantages of high automation, high controllability and the like, and can realize flow line production.

The invention utilizes the transmission characteristic of light and coordinates the relative movement of the laser and the workpiece to realize the irradiation of the whole inner surface by the laser and realize the finish machining of the whole inner surface. The processing method provided by the invention uses the traditional honing process thought for reference, realizes the finishing processing of the inner surface of the whole hole, and the efficiency is essentially improved. The high-efficiency, green and high-precision processing method for the elongated hole can be finally formed. In addition, after laser micromachining, a micro-nano scale stripe structure is usually induced on the surface of the workpiece, and the micro-nano structure can improve the wettability of the workpiece. Through modulation, the pores can have lipophilicity or hydrophilicity, so that the performance of the workpiece in lubrication, cooling and the like is greatly improved.

On one hand, the machining lines left on the inner surface of the machined elongated hole can be efficiently removed, and the roughness of the inner surface is reduced; on the other hand, the temperature of the inner surface of the hole is raised by utilizing the heat conduction caused by the laser energy, and the heat treatment effects of annealing, tempering, normalizing, quenching and the like can be generated under proper conditions, so that the processing quality of the hole is effectively improved; in addition, the laser processing can induce micro-nano-scale stripes on the surface of the material, and can improve the wetting property of the material.

Drawings

Fig. 1 is a schematic view of a processing system for modulating the inner surface of a high depth-to-diameter ratio hole by using a laser in example 1.

Fig. 2 is a schematic view of a processing system for modulating the inner surface of a high depth-to-diameter ratio hole by using laser in example 2.

The device comprises a laser 1, a laser 2, an attenuator 3, a half-wave plate 4, a linear polarizer 5, a mechanical shutter 6, a reflecting mirror 7, a quarter-wave plate 8, a lens 9, a displacement table 10, a computer control system 11, a galvanometer 12, an f-theta mirror 13, a workpiece 14 and a reflecting mirror.

Detailed Description

Fig. 1 is a preferred embodiment of the present invention, which is further described below with reference to fig. 1 ~ 2.