CN104212957A - Metal material laser surface quenching absorption paint and preparation and application methods thereof - Google Patents

Abstract

The invention belongs to the field of coatings, and in particular relates to a metal material laser surface quenching absorption coating and a preparation and application method thereof. The metal material laser surface quenching and absorbing coating of the present invention is composed of fly ash and carbon black, wherein the quality of fly ash accounts for 70-75% of the coating quality; its preparation method is to grind the raw materials fly ash and carbon black respectively , use a sieve to sieve the ground powder, keep the powder with a particle size > 600 mesh, and mix it thoroughly, wherein the quality of the fly ash powder accounts for 70-75% of the total mass of the mixed powder; The laser surface quenching absorbing paint powder and solvent are mixed according to the mass ratio of 1: (4~6), and stirred to fully dissolve the powder. Before the laser surface modification of the metal material, the paint dissolved in the solvent is coated on the metal material surface and dry. The laser absorbing paint of the invention has low cost, can form a film on metal workpieces well, has strong adhesion, short drying time, and the laser absorbing rate is as high as 95%.

Description

A kind of metal material laser surface quenching absorption coating and its preparation and application method

technical field

The invention belongs to the field of coatings, and in particular relates to a metal material laser surface quenching absorption coating and a preparation and application method thereof.

Background technique

In modern industry, high-energy laser beams are often used to modify the surface of ferrous metal materials, such as surface quenching, surface cladding and surface alloying. However, industrial lasers generally use CO ₂ as the luminescent medium, and the reflectivity of ferrous metal materials to CO ₂ lasers is as high as 90%, which not only causes energy waste but also causes harm to the operator's body.

Fly ash is an appendage of coal application and belongs to waste. my country is a country with a large amount of fly ash resources, with an annual emission of more than 160 million tons. A large amount of fly ash will occupy land, pollute the environment, and endanger human health. Production and life cause great harm, so it is urgent to research and develop the application field of fly ash waste utilization research.

In order to improve the absorptivity of metal materials for laser light of this wavelength, increase the absorption of laser energy on the surface of metal materials, and strengthen the quenching effect of laser surfaces, it is necessary to develop a new type of metal surface absorption-enhancing coating. The main components of the absorbing coatings that have been developed are carbon powder, graphite, carbon black, shellac, and silicon carbide and aluminum oxide. Although it can increase the laser absorption rate to a certain extent, it is necessary to prepare carbide oxide powder first. , including steps such as milling and grinding, the cost of milling is relatively high, and there are disadvantages of high cost and instability, and the effect is not very satisfactory.

Contents of the invention

In order to solve the above problems, the present invention provides a metal material laser surface quenching absorption coating and its preparation and application method, the purpose is to improve the absorption rate of the metal surface to the laser light, and reduce the production cost at the same time.

The metal material laser surface quenching absorbing coating for realizing the purpose of the present invention is composed of fly ash and carbon black, wherein the quality of fly ash accounts for 70-75% of the coating mass.

The preparation method of metal material laser surface quenching absorption coating of the present invention is:

Grind the raw materials fly ash and carbon black separately, sieve the ground powder with a sieve, keep the powder with a particle size > 600 mesh, and mix them thoroughly, and the mass of the fly ash powder accounts for the total amount of the mixed powder. 70-75% of the mass to obtain laser surface quenching absorption coating powder.

The using method of metal material laser surface quenching absorption coating of the present invention is:

(1) Mix the laser surface quenching and absorbing coating powder with the solvent at a mass ratio of 1: (4~6), and stir to fully dissolve the powder;

(2) Before the laser surface modification of the metal material, the paint dissolved in the solvent is applied to the surface of the metal material and dried.

Wherein, the solvent is composed of ethanol and binder shellac, and the mass fraction of each component is: ethanol 75-85%, shellac 15-25%.

Compared with prior art, feature and beneficial effect of the present invention are:

(1) In the prior art, graphite, silicon oxide, silicon carbide, aluminum oxide, etc. are used as main materials to develop coatings, and the cost is relatively high. However, the present invention uses coal industry waste fly ash as the main material, which can greatly reduce Coating cost, and the process is simple and easy to operate;

(2) The laser surface quenching absorbing coating of the present invention can form a film on the metal workpiece well, has strong adhesion, short drying time, and the laser absorption rate is as high as 95%.

Description of drawings

Fig. 1 is the microstructure figure of the hardened layer after laser modification of 65Mn steel coated with laser surface quenching absorbing paint in Example 1 of the present invention;

Fig. 2 is a laser sintering microstructure diagram of Ni75Al25 coated with a laser surface quenching absorbing coating in Example 2 of the present invention after laser sintering.

Detailed ways

What the embodiment of the present invention adopts is H-R 150-A type Rockwell hardness tester to metal material hardness test.

Example 1

The metal material laser surface quenching absorption coating of this embodiment is composed of fly ash and carbon black, wherein the mass of fly ash accounts for 70% of the coating mass.

Its preparation method is:

Grind the raw materials fly ash and carbon black separately, sieve the ground powder with a sieve, keep the powder with a particle size > 600 mesh, and mix them thoroughly, and the mass of the fly ash powder accounts for the total amount of the mixed powder. 70% of the mass to obtain the laser surface quenching absorption coating powder.

Its usage is:

(1) Mix the laser surface quenching and absorbing coating powder with the solvent at a mass ratio of 1:4, and stir to fully dissolve the powder;

(2) Before the laser surface modification of 65Mn steel (cylindrical style 15×30mm), the paint dissolved in the solvent is applied to the surface and dried, and the coating thickness is 60 μm. The solvent is composed of ethanol and bonding The composition of shellac, the mass fraction of each component is: ethanol 85%, shellac 15%.

The CO ₂ laser is used to quench the 65Mn steel coated with the laser surface quenching and absorbing coating. The control laser power is 2000W, the scanning speed is 3.5mm/s, and the spot diameter is 4mm . After quenching, the hardness of the sample is 62.9HRC, and the depth of the hardened layer is up to 1140 μm, as shown in Figure 1, the crescent shape is the phase transformation hardening zone; through the thermocouple and computer data acquisition system, the fixed-point temperature of the metal material is collected, and combined with numerical simulation, it is measured that the laser surface quenching absorption coating of this embodiment has a The absorption rate of the laser light is at least 95%.

Comparative example:

After brushing with a single carbon black + solvent (the composition ratio is based on the mass fraction: solute carbon black: 85%, solvent: ethanol and shellac 15%), the same laser process is used for the same material, and the hardness of the sample after quenching treatment It is only 51.2HRC, and the depth of the hardened layer is 840 μm, indicating that the laser surface quenching absorption coating of this embodiment has better adhesion and laser absorption effect.

Example 2

The metal material laser surface quenching absorption coating of this embodiment is composed of fly ash and carbon black, wherein the mass of fly ash accounts for 75% of the coating mass.

Its preparation method is:

Grind the raw materials fly ash and carbon black separately, sieve the ground powder with a sieve, keep the powder with a particle size > 600 mesh, and mix them thoroughly, and the mass of the fly ash powder accounts for the total amount of the mixed powder. 75% of the mass to obtain laser absorbing coating powder.

Its usage is:

(1) Mix the laser surface quenching and absorbing coating powder with the solvent at a mass ratio of 1:5, and stir to fully dissolve the powder;

(2) Before the laser surface modification of the Ni75Al25 powder compact surface, the paint dissolved in the solvent is applied on the surface and dried, and the coating thickness is 70 μm. The solvent is composed of ethanol and binder shellac , the mass fraction of each component is: ethanol 80%, shellac 20%.

The CO ₂ laser was used to sinter the surface of the Ni75Al25 powder compact coated with laser-absorbing coatings. The results showed that Ni and Al had a good reaction, and the structure was uniform and fine. As shown in Figure 2, the white is the Ni ₃ Al phase. After testing, its surface hardness is 32HRC; through the thermocouple and computer data acquisition system to collect the fixed-point temperature of the metal material, combined with numerical simulation, it is measured that the laser absorption coating of this embodiment has an absorption rate of at least 95% of the laser.

Comparative example:

After brushing with a single carbon black + solvent (the composition ratio is based on the mass fraction: solute carbon black: 85%, solvent: ethanol and shellac 15%), the same laser sintering process is used for the same material, and the sample after sintering treatment The hardness is only 21.6HRC, indicating that the laser absorbing coating of this embodiment has better adhesion and laser absorbing effect.

Example 3

The metal material laser surface quenching absorption coating of this embodiment is composed of fly ash and carbon black, wherein the mass of fly ash accounts for 72% of the coating mass.

Its preparation method is:

Grind the raw materials fly ash and carbon black separately, sieve the ground powder with a sieve, keep the powder with a particle size > 600 mesh, and mix them thoroughly, and the mass of the fly ash powder accounts for the total amount of the mixed powder. 72% of the mass to obtain the laser surface quenching absorption coating powder.

Its usage is:

(1) Mix the laser surface quenching and absorbing coating powder with the solvent at a mass ratio of 1:6, and stir to fully dissolve the powder;

(2) Before the laser surface modification of GCr15 steel (cylindrical style 15×30mm) steel, the paint dissolved in the solvent was applied on the surface and dried, and the coating thickness was 60 μm. The solvent was composed of ethanol and viscose The binder shellac is composed, and the mass fraction of each component is: ethanol 75%, shellac 25%.

The 65Mn steel coated with laser-absorbing paint was quenched by a CO ₂ laser, the laser power was controlled at 2000W, the scanning speed was 3.5mm/s, and the spot diameter was 4mm. After quenching, the hardness of the sample was 65.1HRC, and the depth of the hardened layer reached 1270μm Carry out fixed-point temperature collection on metal materials through thermocouples and computer data acquisition systems, combined with numerical simulation, it is measured that the laser absorption rate of the laser surface quenching absorption coating of this embodiment is at least 95%.

Comparative example:

After brushing with a single carbon black + solvent (the composition ratio is based on the mass fraction: solute carbon black: 85%, solvent: ethanol and shellac 15%), the same laser process is used for the same material, and the hardness of the sample after quenching treatment It is only 52.9HRC, and the depth of the hardened layer is 896 μm, indicating that the laser surface quenching absorption coating of this embodiment has better adhesion and laser absorption effect.

Claims (4)

1. A metal material laser surface quenching absorption coating is characterized in that it is made up of fly ash and carbon black, wherein the quality of fly ash accounts for 70-75% of the coating quality. 2. A preparation method for a metal material laser surface quenching absorption coating is characterized in that it is carried out according to the following steps: Grind the raw materials fly ash and carbon black separately, sieve the ground powder with a sieve, keep the powder with a particle size > 600 mesh, and mix them thoroughly, and the mass of the fly ash powder accounts for the total amount of the mixed powder. 70-75% of the mass to obtain laser surface quenching absorption coating powder. 3. A method for using a metal material laser surface quenching absorption coating, characterized in that it is carried out according to the following steps: (1) Mix the laser surface quenching and absorbing coating powder with the solvent at a mass ratio of 1: (4~6), and stir to fully dissolve the powder; (2) Before the laser surface modification of the metal material, the paint dissolved in the solvent is applied to the surface of the metal material and dried. 4. The method for using the metal material laser surface quenching absorption coating according to claim 3, wherein the solvent is composed of ethanol and binder shellac, and the mass fraction of each component is: ethanol 75 ~ 85% , Shellac 15~25%.