CN206298642U - It is a kind of that the laser cladding equipment for preheating gentle cold light is produced based on bifocal - Google Patents

Abstract

The utility model discloses a laser cladding equipment based on a bifocal lens to generate preheating and slow cold light, the equipment includes: a laser, a reflector, a bifocal lens, a powder feeding system, and a workbench; wherein, the workpiece is placed on the workbench on and below the bifocal lens; the laser outputs laser horizontally, and the laser is reflected by the reflector and then vertically incident on the bifocal lens. The short focal length focal point is located above the surface of the workpiece and irradiates the substrate to form a spot centered on the optical axis. In this way, the high power density in the middle is used to melt the surface of the substrate to form a molten pool, and the surrounding power density is low, which is suitable for preheating and post-processing treatment. Such a layout forms a reasonable preheating, cladding, and heat treatment process, which greatly improves the utilization rate of laser energy, reduces the temperature gradient during the cladding process, and reduces the residual stress in the coating.

Description

A laser cladding equipment based on bifocal lens to generate preheating and slow cooling light

technical field

The utility model relates to the technical field of laser cladding processing, in particular to a laser cladding equipment which generates preheating and slow cooling light based on a bifocal lens.

Background technique

As the main symbol of the development of science and technology in the 20th century and one of the pillars of optoelectronic technology in the modern information society, the development of laser technology and laser industry has been highly valued by the world's advanced countries. Laser processing is the largest project in laser applications at home and abroad, and it is also an important means of transforming traditional industries. It mainly realizes cutting, welding, cladding, drilling, engraving and heat treatment of various materials. Among them, laser cladding processing is a multidisciplinary interdisciplinary application technology developed in the past ten years. It is a material accumulation "remanufacturing" method developed on the basis of computer technology, material science, laser technology, numerical control technology and detection technology.

Laser cladding is an extremely fast dynamic melting and solidification process with a high crack rate at room temperature. Preheating and cooling slowly on the surface of the substrate can reduce the excessive temperature gradient generated during the cladding process, thereby reducing or avoiding the occurrence of cracks. The preheating and slow cooling of the substrate actually reduces the temperature gradient of the cladding layer from the surface to the inside through preheating, that is, slows down the cooling rate of the cladding layer, thereby reducing the cracking probability of the cladding layer. Without preheating and slow cooling of the substrate, the bonding strength between the material and the substrate is low, while the surface preheating and slow cooling of the substrate can produce good bonding strength. Under the same conditions, preheating and slow cooling of the substrate is an effective measure to reduce the tendency of cracking.

At present, the preheating and slow cooling methods commonly used in the laser cladding process mainly include heating provided outside the system and using laser heating. Application No. 'CN200710159310.8' High thermal conductivity substrate laser cladding processing method and the system used; Wei Qingsong et al. in 2009 the preheating system of "Preheating Optimization Design for Large Mesa Selective Laser Sintering Rapid Prototyping"; Gao Xuesong in 2012 "Microstructure and Oxidation Resistance of High Frequency Induction-Assisted Laser Cladding MCrAlY Coatings" all use external heating to obtain coatings with better surface morphology, but these methods have low energy utilization and complex structures. Waiting is not enough.

The application number is 'CN201110352257.X', which has preheating and postheating functions and an efficient three-beam laser cladding method for crack-free coating; the application number is 'CN201410480190.1', and a laser cladding process uses The method of preheating and slow cooling with a uniform beam adopts the arrangement of focal points based on the lateral distribution of the working surface. The preheating and slow cooling lasers are always on the same plane, and the cladding path can only be a straight line. However, in the actual processing process, the crack shape of the part is complex and the length is very short. The laser beam trajectory must match the crack shape at all times. This method has the disadvantage of low practicability. The application number is 'CN201610144326.0', a method of segmented laser cladding remanufacturing of complex parts with preheating and heat treatment, which adopts one laser segmental processing, and performs preheating processing and slow cooling process respectively. The processing process is complicated and the processing low efficiency.

Utility model content

The purpose of the utility model is to solve the above-mentioned defects in the prior art, and provide a laser cladding equipment based on a bifocal lens to generate preheating and slow cooling light.

The purpose of this utility model can be achieved by taking the following technical solutions:

A laser cladding equipment based on a bifocal lens to generate preheating and slow cooling light, the equipment includes: a laser 1, a mirror 2, a bifocal lens 3, a powder feeding system 5, and a workbench 7;

Wherein, the workpiece 6 is placed on the workbench 7, and is located below the bifocal lens 3;

The laser 1 outputs laser light horizontally. After the laser light is reflected by the reflector 2, it is vertically incident on the bifocal lens 3. The bifocal lens 3 produces two focal points and forms two identical surfaces on the surface of the workpiece 6. The light spot on the optical axis is used for cladding processing, preheating and slow cooling respectively;

The powder feeding system 5 is used for the device to add alloy powder to the molten pool on the surface of the workpiece 6 during the cladding process.

Further, the bifocal lens 3 is composed of two focusing mirrors with different curved surfaces, the focal length of the middle curved surface part is longer, and the focal length of the peripheral curved surface part is shorter.

Further, the bifocal lens 3 produces two focal points and forms two spots of the same optical axis on the surface of the workpiece, the laser beam passing through the intermediate curved surface part is the first beam, and its focal point is located on the surface of the workpiece 6, passing through the peripheral The laser beam of the curved surface portion is the second beam whose focal point is located above the surface of the workpiece 6 .

Further, the first beam is used for cladding processing, and the second beam is used for cladding preheating and slow cooling.

Further, the laser 1 is a Nd:YAG semiconductor-pumped solid-state laser with a gain medium of 1064nm, a spot diameter of 2mm, and a maximum output power of 10KW, which is used to provide a laser cladding light source.

Further, both sides of the bifocal lens 3 are coated with a 1064nm anti-reflection film.

Further, the powder feeding system 5 includes a lateral powder feeding head 4 , and the powder feeding system 5 blows the alloy powder into the molten pool on the surface of the workpiece 6 through the lateral powder feeding head 4 .

Further, the reflector 2 is arranged at an angle of 45 degrees to the laser output horizontally from the laser 1 .

Compared with the prior art, the utility model has the following advantages and effects:

1) A laser cladding equipment based on a bifocal lens to generate preheating and slow cooling light disclosed in this utility model uses a bifocal lens as a cladding focusing mirror, and obtains two focal points at two different positions on the optical axis, and uses a lens Turn one laser beam into two laser beams. Instead of the commonly used method of producing two laser beams with two lasers, or the method of producing two laser beams with one laser plus a complex beam splitting system, the cost and shape of the equipment are reduced, and the complexity of the equipment is reduced.

2) The laser cladding equipment based on the bifocal lens to generate preheating and slow cooling light disclosed in the utility model adopts the long focal length focal point in the central area of the lens to be located on the surface of the workpiece, and the focal point of the short focal length is located above the surface of the workpiece, which is irradiated on the substrate to form a light Axis-centered spot. In this way, the high power density in the middle is used to melt the surface of the substrate to form a molten pool, and the surrounding power density is low, which is suitable for preheating and post-processing treatment. Such a layout forms a reasonable process of preheating, cladding, and heat treatment. As long as the laser starts to act on the workpiece from the edge of the spot during processing, laser cladding with preheating and slow cooling can be realized.

3) The laser cladding equipment based on bifocal lens to generate preheating and slow cooling light disclosed in the utility model is located in the central area for cladding laser, and the device for preheating and slow cooling is located in the peripheral part, the two constitute a The light spot centered on the optical axis is no longer an independent beam with the three in the same linear position. It has the flexibility of single-beam laser processing, and no longer requires that the cladding path can only be a straight line. In the previous single-beam laser processing, the three processing processes of preheating, cladding, and heat treatment were processed separately and repeated multiple times. This equipment reduces processing links, reduces system complexity, simplifies processing procedures, and improves processing efficiency and processing quality. .

4) The laser cladding equipment based on bifocal lens to generate preheating and slow cooling light disclosed in this utility model adopts the method of combining substrate preheating and coating slow cooling, which can greatly improve the utilization rate of laser energy and reduce the melting rate. The temperature gradient during the coating process and the reduction of residual stress in the coating. Reduce the dilution rate of the coating, ensure the metallurgical bond between the coating and the substrate, and reduce the heat-affected zone of the substrate, so as to efficiently obtain a high-performance coating without deformation and cracks. The obtained cladding layer has dense structure and fine grain, which obviously improves the service life of the workpiece and the performance of wear resistance, corrosion resistance, crack resistance and thermal shock resistance.

Description of drawings

Fig. 1 is a composition structure diagram of a laser cladding equipment based on a bifocal lens to generate preheating and slow cooling light disclosed by the utility model;

Among them, 1---laser, 2---mirror, 3---bifocal lens, 4---side powder feeding head, 5---powder feeding system, 6---workpiece, 7-- -Workbench.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the utility model more clear, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the utility model. Obviously, the described The embodiments are some embodiments of the present utility model, but not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Example

As shown in Figure 1, a laser cladding device based on a bifocal lens to generate preheating and slow cooling light disclosed in this embodiment includes: a laser 1, a reflector 2, a bifocal lens 3, a lateral powder feeding head 4, a powder feeding System 5, workpiece 6, workbench 7.

The laser 1 is a Nd:YAG semiconductor-pumped solid-state laser with a gain medium of 1064nm, a spot diameter of 2mm, and a maximum output power of 10KW, which is used to provide a laser cladding light source.

The laser light output horizontally from the laser 1 is reflected by the mirror 2 set at 45 degrees to the horizontal laser light path, and then vertically incident on the bifocal lens 3 .

The bifocal lens 3 is made up of two different curved surfaces, the focal length of the intermediate curved surface part is longer, and its focus is located on the surface of the workpiece, and the focal length of the peripheral curved surface part is shorter, and its focus is located above the surface of the workpiece, so that a single incident light beam is realized. Two different focal points are obtained at different distances in the direction of propagation. By changing the diameter of the intermediate curved surface, the distance between the two focal points can be changed to change the energy distribution of laser energy on the workpiece, thereby changing the laser power ratio between the cladding laser and the preheating and slow cooling laser to ensure the processing effect. Both sides of the bifocal lens 3 are coated with a 1064nm antireflection film.

Due to the short focus, the second beam of the peripheral curved surface part with short focal length is focused on the surface of the workpiece, and along with the beam transmission, finally forms a spot centered on the optical axis on the working surface. Because the focus point is not on the cladding base surface, the power per unit area is lower than the middle part, which is lower than the melting threshold of the substrate surface. The first half of the spot is used for preheating, which generates a preheating temperature of about 300 ° C. Improve the absorption rate of the substrate for the laser beam used for cladding and reduce the temperature gradient in the cladding process.

The first beam of the middle curved surface part with a long focal length is focused on the surface of the workpiece. When in use, the focus of laser cladding is close to the surface of the substrate, forming a high power density cladding laser, acting on the molten pool formed on the surface of the substrate, and feeding powder The lateral powder feeding head 4 in the system 5 blows the alloy powder into the molten pool, and the molten alloy powder is spread on the surface of the substrate. When the laser beam moves away, the cladding layer is rapidly solidified and crystallized to form a coating. The scanning speed is 180-800mm/min, the cladding thickness is 1-2mm, and the powder feeding rate is 30-260g/min.

After the laser cladding process is completed, with the movement of the laser beam, the second half of the second beam of the short-focus peripheral curved surface part is irradiated on the coating, so that the temperature of the coating after the cladding process is controlled at about 300 °C. The formed cladding coating is slowly cooled to reduce the residual stress in the coating and eliminate the cracks in the cladding layer.

In summary, a laser cladding equipment based on a bifocal lens to generate preheating and slow cooling light disclosed in this utility model uses a bifocal lens as a cladding focusing mirror. The central area of the lens radius realizes long focusing, and the peripheral part of the lens realizes short Focusing, forming two focal points on the optical path. The laser cladding equipment adopts a long focal length focus on the surface of the workpiece, and a short focal length focus on the surface of the workpiece, so that the peripheral laser has a large active area and the temperature generated by the action on the substrate is low, which is suitable for preheating and slow cooling after processing. The middle laser processing area is small and the power density is high. The high power density laser locally melts the surface of the substrate to form a molten pool. With a single incident light, it can realize not only laser cladding processing, but also preheating and slow cooling treatment, reducing temperature gradient and thermal stress. Moreover, the laser used for processing and the laser used for preheating and slow cooling are not arranged in a straight line with each other, but are distributed in a circle centered on the optical axis, which has the flexibility of single laser processing, and multiple lasers can simultaneously preheat and melt. Advantages of overlaying and slow cooling, and save the laser used for preheating or slow cooling, or the complex spectroscopic system for preheating and slow cooling laser beams, reduce equipment cost and volume, and improve processing speed and quality.

The above-mentioned embodiment is a preferred implementation mode of the present utility model, but the implementation mode of the present utility model is not limited by the above-mentioned embodiment, and any other changes, modifications and substitutions made without departing from the spirit and principle of the present utility model , combination, and simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present utility model.

Claims (8)

1. it is a kind of that the laser cladding equipment for preheating gentle cold light is produced based on bifocal, it is characterised in that the equipment bag Include：Laser (1), speculum (2), bifocal (3), powder feed system (5), workbench (7)；

Wherein, workpiece (6) is positioned on the workbench (7), and positioned at the lower section of the bifocal (3)；

Laser (1) the horizontal output laser, laser is by after the speculum (2) reflection, impinging perpendicularly on the bifocal On point lens (3), the bifocal (3) produces two focuses and two same optical axis is formed on the surface of workpiece (6) Hot spot, be respectively used to cladding processing and preheating, slow cooling；

Alloy powder is added in molten bath of the powder feed system (5) for the equipment when cladding is processed to workpiece (6) surface.

2. a kind of laser cladding equipment for producing the gentle cold light of preheating based on bifocal according to claim 1, its It is characterised by,

The bifocal (3) is made up of the focus lamp of two different curves, and the focal length of median curved surface part is more long, and periphery is bent The focal length of face part is shorter.

3. a kind of laser cladding equipment for producing the gentle cold light of preheating based on bifocal according to claim 2, its It is characterised by,

The bifocal (3) produces 2 focuses and 2 hot spots of same optical axis is formed on the surface of workpiece, in Between curvature portion laser beam be the first light beam, its focus be located at workpiece (6) surface, by the laser beam of peripheral curvature portion It is the second light beam, its focus is located at the surface of workpiece (6).

4. a kind of laser cladding equipment for producing the gentle cold light of preheating based on bifocal according to claim 3, its It is characterised by,

First light beam is processed for cladding, and second light beam is used for cladding preheating and slow cooling.

5. a kind of laser cladding equipment for producing the gentle cold light of preheating based on bifocal according to claim 1, its It is characterised by,

The laser (1) is Nd for gain media:YAG diode pumped solid state lasers, wavelength is 1064nm, spot diameter It is 2mm, peak power output is 10KW, for providing laser melting coating light source.

6. a kind of laser cladding equipment for producing the gentle cold light of preheating based on bifocal according to claim 5, its It is characterised by,

The two sides of the bifocal (3) is coated with 1064nm anti-reflection films.

7. a kind of laser cladding equipment for producing the gentle cold light of preheating based on bifocal according to claim 1, its It is characterised by,

The powder feed system (5) includes lateral feeding head (4), and the powder feed system (5) will be closed by the lateral feeding head (4) Bronze end is blown into the molten bath on workpiece (6) surface.

8. a kind of laser cladding equipment for producing the gentle cold light of preheating based on bifocal according to claim 1, its It is characterised by,

The speculum (2) is set with the laser of the laser (1) horizontal output in 45 degree.