Ask for the graduation thesis of "Talking about the application of laser processing technology in mold manufacturing". .

Mould industry 200 1. The fourth place totals 242 40.

Application of laser processing technology in mold manufacturing

Jiangsu University of Technology (Zhenjiang, Jiangsu 2 120 13) Zhou Zhangying Jianzhong Dai Yachun

Abstract: With the maturity of laser processing technology and the gradual decline in the price of industrial high-power laser equipment, products and

Mold manufacturing technology has brought new changes. It is discussed from three aspects: die manufacturing, die surface strengthening and maintenance and die replacement.

The laser optimization of mold manufacturing process is analyzed and discussed in detail.

Mold laser; Process optimization

This paper introduces the latest technology of material arrangement and price reduction.

In the industrial age, a new innovation was brought to the manufacturing industry.

Product technology and mould. It is analyzed and discussed in detail.

It is made according to the latest manufacturing technology of molds and molds.

Manufacturing activities, surface strengthening and maintenance, and five dies or molds.

Keywords mold, laser, process optimization

1 quotation

Fierce market competition makes manufacturing enterprises respond to the market quickly.

Demand and one-time manufacturing success are more and more urgent. In the traditional system

In the manufacturing system, a large number of molds are designed, manufactured and produced for product production.

Assembly and debugging will not only cost a lot of money, but also prolong the production time.

The preparation time of product production, thus prolonging the development cycle of new products,

Forming a bottleneck in the manufacturing process. Therefore, how to make it quickly and effectively?

Creating high-quality and low-cost molds and products has become a common problem.

The theme of exploration. With the development of laser processing technology.

The decline in the price of industrial high-power laser equipment has given products and molds

The manufacturing process has brought about great changes. This paper introduces the mold manufacturing, mold.

Surface strengthening and maintenance, mold replacement and other three aspects, the laser plus

The application of tooling in mold manufacturing is discussed.

2 mold manufacturing

2. 1 Laser superposition manufacturing of molds

1982, Professor Nakagawa of Tokyo University of Japan and others proposed to use it.

Manufacturing drawing die by lamination, 1985, a company in California, USA.

This paper introduces the laser superposition manufacturing method of mould and obtains patent, and its work

The process flow is as shown in figure 1, and the principle is to superimpose laser-cut multi-layer thin plates.

And make its shape change gradually, and finally get the required mold base.

Volume geometry. Japan has made great achievements in laser superposition manufacturing of stamping dies.

In the practical stage, the manufactured punch and die have high quality and machining dimensional accuracy.

— — —— — —— — —— — —— — —— — ——

Date of receipt: August 2000 10

It has reached 0. 0 1mm, and the cutting thickness is 12mm. After laser cutting,

On the surface of the incision, the depth is 0. 1 ~ 0.2 mm, hardness 800HV.

Hardened layer, used for stamping steel plate with thickness of 1mm, only hardened by self-cooling.

Can punch 10 000 pieces, such as laser cutting and flame quenching.

Fire can hit 30 thousand to 50 thousand yuan. Because the connection between the thin plates is simple,

Therefore, the cost can be reduced by half and the production cycle is long by using the superposition method to make the stamping die.

Butter. Used for manufacturing compound dies, blanking dies and progressive dies.

Significant economic benefits have been achieved.

Figure 1 Manufacturing Process of Laser Superposition Mould

It consists of die CAD and laser cutting.

Mould CAD/ CAM system based on ASP. NET to realize the flexible manufacturing system of sheet metal processing.

Used for multi-variety and small batch production. Cover with laser cutting sheet

Manufacturing systems for synthesizing arbitrary three-dimensional surfaces are not only used for plastic processing.

It provides a train of thought for implementing FMS in mold industry, and is also of great significance to domestic mold industry.

Mould manufacturing with complex structure, such as mould hole, mesoporous body and complex cold

But pipes and so on. It is also an effective method to manufacture molds quickly and economically.

And can promote the development of other technologies such as solid phase diffusion.

2.2 Rapid Mold Manufacturing

Mould CAD

Three-dimensional design

Two-dimensional shape

Numerical control program

laser

incision

expel

stairway

Wound record

end

form

mould

fix

match

thin slice

ring

end

Numerical control program

Mold manufacturing technology mold industry 200 1. Fourth place, total 242 4 1

Rapid Prototyping (RPM) appeared in the late 1980s.

At present, RPM technology has developed more than a dozen.

Process method. There are many ways to rapidly manufacture molds based on RPM technology.

It is an indirect molding method, that is, using RPM prototype to copy the mold indirectly.

With.

(1) soft and simple mold manufacturing (such as automobile panel mold)

Work. Silicone rubber, low melting point alloy, etc. are used. Copy the prototype to exactly

Mold, or metal spraying method or physical evaporation deposition on the prototype surface.

Coating a layer of alloy with extremely low melting point to make a mold. These are simple.

The service life of the mould is 50 ~ 5000 pieces. It is difficult to manufacture because of its low manufacturing cost.

The production cycle is short, especially suitable for small batch production in the trial production stage of products.

Production.

(2) steel mold manufacturing. RPM prototype -3D grinding wheel

-Integrated graphite electrode-steel mold, medium-sized complex mold.

Miscellaneous electrodes can generally be completed in 4 ~ 8 hours. Ford motor company of America

This technology has achieved satisfactory results in automobile panel die manufacturing.

Compared with the traditional machining die, the rapid die manufacturing is omitted.

In order to avoid free and costly CNC machining, the machining cost and cycle are greatly reduced.

Low, with broad application prospects.

3 die surface strengthening and repair

In order to improve the service life of the die, it is often necessary to modify the surface of the die.

Line reinforcement treatment. Chemical treatment is the commonly used process for strengthening the die surface.

Treatment (such as carburizing, carbonitriding, etc. ), surface composite treatment (such as heap

Welding, thermal spraying, electric spark surface strengthening, PVD and CVD, etc. ) to

And surface treatment strengthening treatment (such as shot peening). Most of these methods are laborious.

Its process is more complicated, the treatment cycle is longer, and there are larger

Deformation. It is very flexible to use laser technology to strengthen and repair molds.

Large, high surface hardness, short process cycle and clean working environment.

Point, so it has strong vitality.

3. 1 laser transformation hardening

Laser transformation hardening (laser quenching) is the use of laser irradiation.

The metal surface makes its surface reach the phase transition temperature at a high heating rate.

Degree (but below the melting temperature) to form austenite.

After that, the heat conduction of the metal surface itself is self-quenched, so that the gold

Martensite transformation occurs on the surface, forming a watch with high hardness and wear resistance.

Layer, so that the metal surface is strengthened. The equipment used is triaxial.

Dynamic numerical control laser processing machine.

The main factors affecting laser strengthening are laser power and spot ruler.

Inches and scanning speed. These parameters should be optimized in the strengthening process.

And select the appropriate laser processing parameters for specific materials. about

CrWMn, Cr 12MoV, Cr 12, T 10A and Cr-Mo cast iron, etc.

After laser treatment, the microstructure and properties of common mold materials are quite ordinary.

Heat treatment is usually improved. For example, when CrWMn steel is conventionally heated,

It is easy to form reticular secondary carbides on austenite grain boundaries, which increases significantly.

The brittleness of the workpiece reduces the impact toughness and is used on the cutting edge or key of the die.

Website life is very short. Fine martensite and martensite can be obtained after laser quenching.

Dispersed carbide particles, remove the network and obtain maximum hardening.

Excitation of steel with layer depth and maximum hardness of1017.2 HV .. Cr12mov.

After light quenching, the hardness, plastic deformation resistance and adhesive wear resistance are good.

The traditional heat treatment method has been improved. The punch is made of T8A steel and

The female die made of Cr 12Mo steel has a laser hardening depth of 0. 12mm and hardness.

1 200HV, the service life is improved by 4 ~ 6 times, not only stamping 20,000 pieces.

To10 ~140,000 pieces. For T 10 steel, the hardness can be obtained by laser quenching.

Hardened layer, with the degree of 1.024 kV and the depth of 0. 55mm for Cr 12, laser

The hardness of hardened layer after quenching is 1 000HV, and the depth is 0. 4mm can be obtained.

The service life is greatly improved.

3.2 Laser coating

Laser coating is to cover the surface of the substrate with a thin layer of laser.

The coating material with specific properties can be metal or alloy.

Gold can also be nonmetal, compound and their mixture.

In the coating process, the coating is communicated with the surface of the substrate under the action of laser.

Over-fusion quickly combines. This is the main field of laser alloying.

The difference is that the chemical composition of the coating is basically unchanged after laser action.

Chemical, the composition of the matrix basically does not enter the coating. Laser coater

The range of practical materials is very wide, and the parent materials being studied are very low.

Carbon steel, alloy steel, cast iron, nickel-chromium-titanium heat-resistant alloy, etc. , a supplement to the study

Materials include cobalt-based alloys, iron-based alloys and nickel-based alloys.

Laser technology is applied to 2kW powder-feeding CO2 laser.

A layer of nickel-based high strength steel was coated on the surface of 4Cr5MoV 1Si steel matrix.

High temperature wear-resistant alloy powder composed of warm alloy and WC+W2C particles.

Finally, when the laser power P = 1 500W and the powder feeding amount is 10g/ min, the working time is 10g/min.

When the moving speed of parts is 2 ~ 3 mm/s, multi-path overlap can be obtained.

Large area high temperature wear resistant alloy. When the test temperature is 600℃, the hardness

550 ~ 580 Hv0.2 When the temperature is 950℃, the hardness is

100~200HV0 .2. It can be seen that at the high temperature of about 65438 0000℃, the coating

It still has high toughness and is an ideal wear-resistant joint for high temperature molds.

Kim. In addition, the worn mold was repaired by laser coating.

And a drawing die. , can greatly extend the service life of the mold and reduce the number of molds.

The use cost of.

3.3 Laser surfacing

In order to improve blanking and trimming dies for some automobile panels,

Long service life, saving high-quality mold materials, and the blade is often used in the poor.

Surfacing a layer of alloy with excellent performance on the base material. In the past, the amount of surfacing welding was large.

The method of artificial oxygen-acetylene flame surfacing is mostly used, although the total number of this method is 242 42 in the equipment "Mould Industry" 2001.No.4.

Low cost but low power density (10

2

~ 10

three

Width/cm2

), and it is difficult.

Precise control, so the surfacing quality and productivity are low. 70

Since 1990s, plasma powder surfacing technology has been developed successfully, because

It has high power density and good control performance, so it is obtained.

Widely used. However, plasma surfacing has electrode life.

Short, high dilution rate of base metal of surfacing layer. Since the 1980s.

The existing laser surfacing method uses the same material as oxygen-acetylene flame.

Compared with surfacing method, laser surfacing layer has fine and dense structure and poor yield.

Only the former110. Laser surfacing has high speed and higher productivity than oxygen.

-acetylene flame surfacing is 1. 75 times higher, and the amount of surfacing materials.

Only 1/ 2. Moreover, the hardness of laser surfacing layer at room temperature is higher than that of oxygen-b

The height of acetylene flame surfacing is about 50HV. Laser surfacing quality and laser

The beam mode, power and surfacing speed are related.

4 laser processing instead of die stamping processing

4. 1 Laser cutting replaces the punching die of sheet metal parts.

Laser cutting replaces sheet metal parts and stamping in automobile body manufacturing

There is a lot of work to be done in trimming dies. Three-dimensional laser cutting technology, because of its originality

Body has the characteristics of flexible processing and quality assurance, and it was in the 1980s.

It began to be used in automobile body manufacturing. When cutting, just use a flat one.

The support block is used to support the workpiece, so the manufacturing of the fixture is not only low in cost, but also

And soon. Due to the combination with CAD/ CAM technology, the cutting process

Easy to control, can realize continuous production and parallel processing, thus realizing

Efficient cutting production.

There are two main types of lasers used to cut plates, namely

CO2 laser and Nd: YA G laser with power of 100 ~ 1 500.

W, because the vibration mode of laser with power less than 1 500W is

Single mode, notch width is 0 0. 1~0.2mm, and the cutting surface is neat.

However, when the output power is greater than 1 500W, the laser has more vibration modes.

Stamping die, notch width is nearly 65438±0mm, and the cutting surface quality is poor. Because Nd:

YA G laser can be transmitted through optical fiber, which is more flexible and convenient.

It is suitable for robot hand-held laser nozzle to be accurately controlled by programming.

Operation, so it is mostly used for three-dimensional cutting. Affect laser cutting

The main factors of workpiece quality are cutting speed, focus position and assistance.

Air pressure, laser output power and mode.

Ford and general motors in the United States and Toyota and Japan.

Laser cutting is widely used in automobile production lines by automobile companies such as production companies.

Technology, it doesn't need to use all kinds of metal molds, except for high speed.

It is convenient to cut blanks with different shapes, and it is also used for mass cutting.

Due to different specifications, it is necessary to change the installation hole position of cutting parts, such as

Car sign lamp, frame, decorative lines on both sides of car body, etc. General Motors Corporation

The diameter of trucks produced by our company is

20 kinds of holes, the company uses Rofin- Sinar's 500W laser beam.

The optical fibers are connected to a welding head mounted on a robot to cut the optical fibers.

Hole, 1 min, finish the processing of a door opening, with smooth hole edge and flat back.

The surface is flat. < 2.8 mm hole tolerance is 0. 03 ~ 0.08 mm,

The tolerance of< 12mm hole is -0. 25mm~+0。 03mm。 duke

The trucks and buses produced by our company have 89 kinds of apertures and different positions.

Chassis, after optimized design, now only needs to play five different types.

Chassis, and then laser cutting holes with different configurations, which simplifies the work.

Art, improve efficiency and reduce costs.

1997, the National Natural Science Foundation of China put high-power CO2

The theory and technology of YA G laser three-dimensional welding and cutting are emphasized.

This project is supported by the research group of National Industry-University-Research Laser Technology Center.

Committee members made a systematic study on this to make the automobile body system in China.

The application of three-dimensional laser stereo machining technology in manufacturing industry has made great contributions.

The center belongs to FAW Car Company and Baoshan Iron and Steel Company.

The technological transformation of large enterprises has implemented major engineering projects, among which

Three-dimensional laser manufacturing technology of domestic red flag extended car panel.

Technology was adopted for the first time in automobile production in China. Automobile sheet

It was first used in the experimental study of laser splicing technology for thick steel plates.

Laser cutting has replaced fine cutting technology and achieved good technical experience.

Economic effects. Three-dimensional laser cutting after body assembly is also very difficult to process.

Useful, such as opening the luggage rack fixing hole, roof slide rail hole, antenna installation.

Hole, modify the wheel fender shape. Used for cutting in new car trial production.

Contour cutting and correction not only shortens the trial production period, but also saves the mold and cost.

It embodies the advantages of laser cutting.

4.2 Laser marking replaces stamping die marking.

Enterprises often need to mark the enterprise self on the parts they produce.

There are symbols or specific symbols and numbers, and the previous method is to use.

When stamping die or molding with die, the marking quality is not high. Adopt digital control

Laser marking is not only fast, but also overcomes common problems in stamping die marking.

Look for burrs, sharp edges and distortions. Due to the adoption of computer control

System, so you can play any complicated mode and eliminate the mold.

Design, manufacture and debugging greatly shorten the development and manufacture of products.

Cycle, but also reduce the cost. Due to the power required by the laser marking machine

Small, low-cost and beautiful signs have been adopted by most enterprises.

Adopted by the industry.

4.3 Laser forming replaces bending die forming.

Laser forming technology of sheet metal is a technology using focused beam.

Scan the surface of the metal plate at a certain speed (the scanning speed should be sufficient

Quickly prevent surface melting), so that the material in the heat affected zone is obvious.

The temperature gradient leads to the uneven distribution of thermal stress, which makes the metal plate

Plastic deformation method. Compared with traditional forming methods, laser forming Die Industry 200 1. There are 242 43 on the 4 th.

It has many advantages: ① it belongs to dieless molding, with short production cycle and flexibility.

Large, can not be limited by the processing environment, by optimizing the laser processing technology

Parameters, accurately control the distribution of thermal action zone and thermal stress, and

Metal plate dieless forming: (2) Because it is a dieless thermal stress.

There is a plastic processing method to deform the metal sheet, so it belongs to no external force.

Form; ③ Non-contact molding, so there is no molding and wear.

And the forming precision is improved.

High; (4) Metal plates can be formed by composite forming to obtain irregular shapes with complex shapes.

Parts (such as spherical parts, conical parts and parabolic parts, etc. ).

The essence of laser forming mechanism is bending mechanism. When laser is added.

When the hot plate material is heated, on the one hand, thermal stress is generated in the laser action area and its surroundings.

Force, at the same time, reduce the yield pole root of the plate in the heating area, therefore,

So that the thermal material in the thermal stress action zone generates uneven plastic deformation.

Forming to realize the bending forming of sheet metal. Experiments show that each laser scanning,

Pass, the metal sheet can be bent 1 ~ 5, and the scanning trajectory and work are different.

The combination of process parameters can produce different forming effects and different degrees.

Deformation, you can get a variety of complex shapes of the workpiece. Figure 2 Table

The technological parameters are laser speed and power 1. 5kW and laser beam diameter.

5.4mm, material SUS304, thickness 1mm, surface condition of carbon coating.

Relationship between laser scanning speed and bending angle of materials.

Fig. 2 Influence of laser scanning speed on bending angle

Now many countries in the world have invested a lot of manpower and material resources.

Special research on laser forming technology has been carried out in some fields.

Started the initial industrial application. Polish Institute of Basic Technology

Professor HFrackiewicz has made cylinders by laser forming.

I-shaped parts, spherical parts, corrugated pipes and metal pipes are flared, necked and bent.

Appearance and so on; German scholar MGeiger and others will use laser forming and other processing.

The processing compound is applied to the automobile manufacturing industry and is used for automobile panels.

Flexible leveling forming parts can also be used for bending forming.

The process is controlled by computer closed loop, which improves the forming accuracy. Germany

1997, Trumpf developed commercial laser forming equipment.

Use the machine tool Trumat ic L 3030. I believe that with the deepening of research

As well as the development of other related technologies, laser forming technology will be gradually developed.

Mature and enter the practical stage.

5 concluding remarks

As an advanced processing technology, laser processing technology has been widely used in China.

Foreign industries have been widely used, while China's machinists have been in the "Nine"

During the five-year plan, it was also regarded as one of the top ten technologies. National natural science

The National Natural Science Foundation of China has also studied laser processing technology and laser processing equipment.

Fund key research projects and clearly point out their main applications.

The field should be automobile manufacturing. As a tool, the mold was born.

Production cycle, quality and cost directly affect the manufacturing process and marketing of products.

Sell. As a general processing tool, laser is reducing the number of molds.

Establish equipment, shorten mold manufacturing cycle, reduce manufacturing costs, and ensure molds.

It has great advantages in quality and so on. How to use it in actual production

The application of laser processing technology to optimize the mold manufacturing process is very important to the traditional

The improvement and combination of mold manufacturing technology needs our continuous efforts.

Work hard.

Take the exam and contribute.

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