CN113667974B - Preparation method of wear-resistant metal-multi-component ceramic composite modified coating on titanium alloy surface - Google Patents

Abstract

The invention relates to a preparation method of a wear-resistant metal-multi-element ceramic composite modified coating on the surface of a titanium alloy, belonging to the technical field of surface engineering and comprising the following steps: (1) preparing prealloying powder for later use; (2) cleaning the surface of the substrate to be clad by using industrial alcohol, and then blackening the surface of the substrate; (3) and (3) conveying the prealloy powder prepared in the step (1) to the surface of the base material to be clad, which is treated in the step (2), through coaxial powder feeding, and carrying out laser cladding to prepare the wear-resistant metal-multi-element ceramic composite modified coating on the surface of the titanium alloy. The composite modified coating prepared by the invention has obvious grain refinement, achieves the purpose of fine grain reinforcement, and ensures that the coating has high hardness and high toughness, thereby greatly improving the wear resistance of the titanium alloy and further prolonging the service life of the titanium alloy under complex working conditions.

Description

Preparation method of wear-resistant metal-multi-component ceramic composite modified coating on titanium alloy surface

technical field

The invention relates to a preparation method of a titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating, belonging to the technical field of surface engineering.

Background technique

Titanium alloys are widely used in aerospace and petrochemical engineering fields due to their high specific strength, high yield-to-strength ratio, and good corrosion resistance. However, due to the inherent shortcomings of titanium alloys such as high friction coefficient, poor wear resistance, and low high temperature oxidation resistance, it will seriously affect the service life of its service parts and limit its wider application in the aerospace industry. Studies have shown that surface modification techniques such as laser cladding are effective means to improve the surface properties of titanium alloys.

Laser cladding technology is an emerging technology that uses high-energy lasers and metal powder materials to strengthen and remanufacture various parts. The service life of parts can achieve the purpose of increasing production and reducing consumption. The laser surface modification of titanium alloy is based on ensuring the original performance of the substrate, using a high-energy laser beam to directly prepare the surface of the alloy with excellent wear resistance, high temperature oxidation resistance, thermal fatigue resistance, and can form a firm with the substrate. Metallurgically bonded modified coatings to improve the performance of parts.

At present, the laser surface cladding material system mostly adopts the metal-ceramic composite coating on the alloy surface, which can organically combine the better mechanical properties of the alloy with the excellent wear resistance, corrosion resistance, high temperature oxidation resistance and chemical stability of the ceramic material. , to solve the current "bottleneck" of titanium alloy performance. In recent years, research on wear-resistant coatings on the surface of laser cladding titanium alloys has been widely carried out, but there are still many problems to be solved, such as the balance between the hardness and toughness of the coating, and the problem of cracks easily generated when the hardness of the coating is too high. In addition, because laser processing is different from traditional processing such as casting, it is an open processing. At the moment of laser irradiation, the metal-ceramic elements added to the powder material are melted and decomposed, and even evaporation or ablation are very complicated. The physical and chemical changes caused by the waste of materials also deviate from the original intention of the design.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a method for preparing a wear-resistant metal-multi-component ceramic composite modified coating on the surface of titanium alloy, adding a multi-component insoluble ceramic phase to the metal powder, and during the rapid cooling of the cladding layer, the refractory metal or The ceramic phase acts as the core of heterogeneous nucleation, so that the prepared coating can be strengthened by fine grains, thereby improving the strength and toughness of the coating, and maintaining the high hardness of the coating without causing cracks.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A method for preparing a titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating, comprising the following steps:

(1) Prepare pre-alloyed powder for use;

(2) Use industrial alcohol to clean the surface of the substrate to be clad, and then blacken the surface of the substrate;

(3) The pre-alloyed powder prepared in step (1) is transported to the surface of the substrate to be cladding treated in step (2) through coaxial powder feeding, and laser cladding is performed to prepare a titanium alloy surface wear-resistant metal-multi-element Ceramic composite modified coating;

The process parameters of the laser cladding are as follows: the laser power is 3.5-4.0KW, the rectangular light spot is 2×14 mm, the overlap ratio is 10-30%, the scanning speed is 550-700 mm/min, and the protective gas is argon gas , the powder feeding speed is 1.5～4.5g/s, and the powder feeding air flow is 8L/min.

A further improvement of the technical solution of the present invention is that the specific steps of the step (1) include:

S1. Take four powders of HfC, TaC, ZrC and NbC with a particle size of 100-270 mesh and mix them in a mass ratio of 1:1:1:1;

S2, put the powder mixed by S1 into a high-energy ball mill, and perform ball milling to obtain a ground ceramic phase powder;

S3, take spherical titanium alloy powder with a particle size of 400-500 mesh, put the titanium alloy powder and the ceramic phase powder obtained by grinding in S2 into a ball mill for ball milling to obtain a ground pre-alloyed powder.

The further improvement of the technical scheme of the present invention is: the grinding balls used in the S2 and S3 ball milling are corundum balls with diameters of 1 mm and 3 mm, the quantitative ratio of the two grinding balls is 1:4, and the volume ratio of the balls is 3:1, The ball milling time is 6 to 12 hours.

A further improvement of the technical solution of the present invention is that the mass percentage of the ceramic phase powder in the pre-alloyed powder obtained from S3 is 5% to 15%.

A further improvement of the technical solution of the present invention is that the thickness of the wear-resistant metal-multi-element ceramic composite modified coating on the surface of the titanium alloy obtained in the step (3) is 0.6-1.2 mm.

Owing to having adopted the above-mentioned technical scheme, the technical effects obtained by the present invention are as follows:

The Rockwell hardness of the composite modified coating prepared by the invention is about 150% higher than that of the substrate surface without laser cladding, and about 28% higher than that of the TC4 coating without adding a multi-component ceramic phase. The grain refinement is obvious, which achieves the purpose of grain refinement strengthening, and ensures that the coating has high hardness and high toughness, which can greatly improve the wear resistance of titanium alloys, thereby improving the service life of titanium alloys under complex working conditions. .

The composite modified coating obtained under the preparation conditions of the present invention has high hardness and good toughness, and does not have the problem of cracks. The composite modified coating obtained under the preparation conditions of the present invention has poor toughness and is prone to cracks.

Description of drawings

Fig. 1 is the microstructure diagram of the coating of embodiment 2 of the present invention;

Fig. 2 is the microstructure diagram of the coating of Comparative Example 1 of the present invention;

Fig. 3 is the microstructure diagram of the coating of Comparative Example 2 of the present invention;

Fig. 4 is the EDS composition of the coating of embodiment 2 of the present invention;

Fig. 5 is the EDS composition of the coating of Comparative Example 1 of the present invention;

6 is a microhardness comparison diagram of Example 2 of the present invention and Comparative Example 1;

Fig. 7 is the variation curve of the microhardness of the coating of Comparative Example 2.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not intended to limit the present invention.

A method for preparing a titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating, comprising the following steps:

(1) Preparation of pre-alloyed powder, which specifically includes the following steps:

S1. Take four powders of HfC, TaC, ZrC and NbC with a particle size of 100-270 mesh and mix them in a mass ratio of 1:1:1:1;

S2, put the powder mixed by S1 into a high-energy ball mill, and perform ball milling to obtain a ground ceramic phase powder;

S3, take spherical titanium alloy powder with a particle size of 400-500 mesh, put the titanium alloy powder and the ceramic phase powder obtained by grinding S2 into a ball mill together for ball milling to obtain a ground pre-alloyed powder, the pre-alloyed powder in the ceramic phase powder The mass percentage is 5% to 15%.

Wherein, the grinding balls used in the S2 and S3 ball milling are corundum balls with diameters of 1 mm and 3 mm, the quantity ratio of the two grinding balls is 1:4, the volume ratio of the balls is about 3:1, and the ball milling time is 6-12 Hour.

(2) Use industrial alcohol to clean the surface of the substrate to be clad to remove impurities such as oil stains, and then blacken the surface of the substrate.

(3) The pre-alloyed powder prepared in step (1) is transported to the surface of the substrate to be cladding treated in step (2) through coaxial powder feeding, and laser cladding is performed to prepare titanium with a thickness of 0.6-1.2 mm. Wear-resistant metal-multi-ceramic composite modified coating on alloy surface;

The process parameters of the laser cladding are as follows: the laser power is 3.5-4.0KW, the rectangular light spot is 2×14 mm, the overlap ratio is 10-30%, the scanning speed is 550-700 mm/min, and the protective gas is argon gas , the powder feeding speed is 1.5～4.5g/s, and the powder feeding air flow is 8L/min.

Example 1

A method for preparing a titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating, comprising the following steps:

(1) Preparation of pre-alloyed powder, including the following steps:

S1, take the particle size: take four powders of HfC, TaC, ZrC and NbC with a particle size of 100-270 mesh, and mix them in a mass ratio of 1:1:1:1;

S2. Put the mixed powder into a high-energy ball mill for ball milling. During ball milling, the grinding balls are mixed corundum balls with diameters of 1 mm and 3 mm and a quantity ratio of 1:4. The volume ratio of the balls is about 3:1. The ball milling time For 12 hours, the ground ceramic phase powder was obtained;

S3. Take the spherical TC4 powder with a particle size of 400-500 mesh, and put the ceramic phase powder obtained by grinding the TC4 powder and S2 into a ball mill for ball milling. The percentage of the ceramic phase powder in the total mass of the powder is 5%. The size, proportion and ball-to-material ratio of the balls are the same as those of S2, and the ball milling time is 6 hours to obtain the ground pre-alloyed powder.

(2) Use industrial alcohol to clean the surface of the TC4 board substrate to be clad to remove impurities such as oil stains, and then blacken the surface of the substrate.

(3) The prepared pre-alloyed powder is transported to the surface of the substrate to be clad by coaxial powder feeding for laser cladding. The laser power is: 3.8 KW, the rectangular spot is: 2 × 14 mm, and the overlap ratio is: 30%, scanning speed: 550mm/min, shielding gas: argon, powder feeding speed: 4.5g/s, powder feeding gas flow rate: 8 L/min, to obtain the cladding layer (wear-resistant metal-multi-element titanium alloy surface) Ceramic composite modified coating), the thickness of the cladding layer is 1.2mm.

The surface of the cladding layer is inspected by coloring to detect no crack defects; then the cladding layer is ground with a unilateral grinding amount of 0.3mm to obtain a reinforced titanium alloy backing plate with dimensions, tolerances and surface finish that meet the requirements. And the surface of the cladding layer is smooth and the average hardness is 60HRC.

Example 2

A method for preparing a titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating, comprising the following steps:

(1) Preparation of pre-alloyed powder, including the following steps:

S1. Take four powders of HfC, TaC, ZrC and NbC with a particle size of 100-270 mesh and mix them in a mass ratio of 1:1:1:1;

S2. Put the mixed powder into a high-energy ball mill for ball milling. During ball milling, the grinding balls are mixed corundum balls with diameters of 1 mm and 3 mm and a quantity ratio of 1:4. The volume ratio of the balls is about 3:1. The ball milling time For 10 hours, the ground ceramic phase powder was obtained;

S3. Take spherical TC4 powder with a particle size of 400-500 mesh, and grind the ceramic phase powder obtained by grinding the TC4 powder and S2 into a ball mill for ball milling, wherein the ceramic phase powder accounts for 10% of the total mass. , the ratio and the ball-to-material ratio are the same as those of S2, the ball milling time is 6 hours, and the ground pre-alloyed powder is obtained.

(2) Use industrial alcohol to clean the surface of the TC4 board substrate to be clad to remove impurities such as oil stains, and then blacken the surface of the substrate.

(3) The prepared pre-alloyed powder is transported to the surface of the substrate to be clad by coaxial powder feeding for laser cladding. The laser power is: 4.0 KW, the rectangular spot is: 2 × 14 mm, and the lap rate is: 20%, scanning speed: 700mm/min, shielding gas: argon, powder feeding speed: 2.5g/s, powder feeding gas flow rate: 8 L/min, to obtain the cladding layer (wear-resistant metal-multi-component titanium alloy surface) Ceramic composite modified coating), the thickness of the cladding layer is 0.8mm.

The surface of the cladding layer is inspected by coloring to detect no crack defects; the cladding layer is ground and the unilateral removal amount is 0.3mm, and a reinforced titanium alloy backing plate with dimensions, tolerances and surface finish that meets the requirements is obtained. The surface of the coating is smooth and the average hardness is 64HRC.

Example 3

A method for preparing a titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating, comprising the following steps:

(1) Preparation of pre-alloyed powder, including the following steps:

S1. Take four powders of HfC, TaC, ZrC and NbC with a particle size of 100-270 mesh and mix them in a mass ratio of 1:1:1:1;

S2. Put the mixed powder into a high-energy ball mill and perform ball milling. During ball milling, the grinding balls are mixed corundum balls with diameters of 1 mm and 3 mm and a quantity ratio of 1:4. The volume ratio of the balls is about 3:1. The ball milling time About 10 hours, the ground ceramic phase powder is obtained;

S3. Take the spherical TC4 powder with a particle size of 400-500 mesh, and put the multi-component ceramic phase powder obtained by grinding the TC4 powder and S2 into a ball mill for ball milling, wherein the ceramic phase powder accounts for 15% of the total mass. Perform ball milling, and grind the balls during ball milling. The size, proportion and ball-to-material ratio are the same as those of S2, the ball milling time is 6 hours, and the ground pre-alloyed powder is obtained.

(2) Use industrial alcohol to clean the surface of the TC4 board substrate to be clad to remove impurities such as oil stains, and then blacken the surface of the substrate.

(3) The prepared pre-alloyed powder is transported to the surface of the substrate to be clad by coaxial powder feeding for laser cladding. The laser power is: 4.0 KW, the rectangular spot is: 2 × 14 mm, and the lap rate is: 10%, scanning speed: 700mm/min, shielding gas: argon, powder feeding speed: 1.5g/s, powder feeding gas flow rate: 8 L/min, to obtain a cladding layer (wear-resistant metal-multi-element titanium alloy surface) Ceramic composite modified coating), the thickness of the cladding layer is 0.6mm.

The cladding layer is subjected to surface coloring inspection to detect no crack defects; the cladding layer is polished, and the unilateral removal amount is 0.2mm, and a reinforced titanium alloy backing plate with dimensions, tolerances and surface finish that meets the requirements is obtained, and the cladding is carried out. The surface of the layer is smooth and the average hardness is about 62HRC.

Example 4

A method for preparing a titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating, comprising the following steps:

(1) Preparation of pre-alloyed powder, including the following steps:

S1. Take four powders of HfC, TaC, ZrC and NbC with a particle size of 100-270 mesh and mix them in a mass ratio of 1:1:1:1;

S2. Put the mixed powder into a high-energy ball mill for ball milling. During ball milling, the grinding balls are mixed corundum balls with diameters of 1 mm and 3 mm and a quantity ratio of 1:4. The volume ratio of the balls is about 3:1. The ball milling time About 6 hours, the ground ceramic phase powder is obtained;

S3. Take spherical TC4 powder with a particle size of 400-500 mesh, and grind the ceramic phase powder obtained by grinding the TC4 powder and S2 into a ball mill for ball milling, wherein the ceramic phase powder accounts for 10% of the total mass. , the ratio and the ball-to-material ratio are the same as those of S2, the ball milling time is 12 hours, and the ground pre-alloyed powder is obtained.

(2) Use industrial alcohol to clean the surface of the TC4 board substrate to be clad to remove impurities such as oil stains, and then blacken the surface of the substrate.

(3) The prepared pre-alloyed powder is transported to the surface of the substrate to be clad by coaxial powder feeding for laser cladding. The laser power is: 3.5KW, the rectangular spot is: 2 × 14 mm, and the lap rate is: 30%, scanning speed: 550mm/min, shielding gas: argon, powder feeding speed: 4.5g/s, powder feeding gas flow rate: 8 L/min, to obtain the cladding layer (wear-resistant metal-multi-element titanium alloy surface) Ceramic composite modified coating), the thickness of the cladding layer is 1.2mm.

The surface of the cladding layer is inspected by coloring to detect no crack defects; the cladding layer is ground and the unilateral removal amount is 0.3mm, and a reinforced titanium alloy backing plate with dimensions, tolerances and surface finish that meets the requirements is obtained. The surface of the coating is smooth and the average hardness is 63.5HRC.

Comparative Example 1

A preparation method of a titanium alloy surface wear-resistant metal coating, comprising the following steps:

(1) Take spherical TC4 powder with a particle size of 400-500 mesh and set it aside.

(2) Use industrial alcohol to clean the surface of the TC4 board substrate to be clad to remove impurities such as oil stains, and then blacken the surface of the substrate.

(3) The prepared pre-alloyed powder is transported to the surface of the substrate to be clad by coaxial powder feeding, and laser cladding is performed. The laser power is: 4.0KW, the rectangular spot is: 2 × 14 mm, and the overlap ratio is: 20%, scanning speed: 700mm/min, shielding gas: argon, powder feeding speed: 2.5g/s, powder feeding gas flow rate: 8 L/min, to obtain the cladding layer (wear-resistant metal-multi-component titanium alloy surface) Ceramic composite modified coating), the thickness of the cladding layer is 0.8mm.

The surface of the cladding layer is inspected by coloring to detect no crack defects; the cladding layer is ground and the unilateral removal amount is 0.3mm, and a reinforced titanium alloy backing plate with dimensions, tolerances and surface finish that meets the requirements is obtained. The surface of the coating is smooth and the average hardness is 50HRC.

Comparative Example 2

A method for preparing a titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating, comprising the following steps:

(1) Preparation of pre-alloyed powder, including the following steps:

S1. Take three powders of HfC, TaC and ZrC with a particle size of 100-270 mesh, and mix them with a mass ratio of 1:1:1;

S2. Put the mixed powder into a high-energy ball mill for ball milling. During ball milling, the grinding balls are mixed corundum balls with diameters of 1 mm and 3 mm and a quantity ratio of 1:4. The volume ratio of the balls is about 3:1. The ball milling time For 10 hours, the ground ceramic phase powder was obtained;

S3. Take spherical TC4 powder with a particle size of 400-500 mesh, and grind the ceramic phase powder obtained by grinding the TC4 powder and S2 into a ball mill for ball milling, wherein the ceramic phase powder accounts for 10% of the total mass. , the ratio and the ball-to-material ratio are the same as those of S2, the ball milling time is 6 hours, and the ground pre-alloyed powder is obtained.

(2) Use industrial alcohol to clean the surface of the TC4 board substrate to be clad to remove impurities such as oil stains, and then blacken the surface of the substrate;

(3) The prepared pre-alloyed powder is transported to the surface of the substrate to be clad by coaxial powder feeding, and laser cladding is performed. The laser power is: 4.0KW, the rectangular spot is: 2 × 14 mm, and the overlap ratio is: 20%, scanning speed: 700mm/min, shielding gas: argon, powder feeding speed: 2.5g/s, powder feeding gas flow rate: 8 L/min, to obtain the cladding layer (wear-resistant metal-multi-component titanium alloy surface) Ceramic composite modified coating), the thickness of the cladding layer is 1.8mm;

The surface of the cladding layer is inspected by coloring to detect no crack defects; the cladding layer is ground and the unilateral removal amount is 0.3mm, and a reinforced titanium alloy backing plate with dimensions, tolerances and surface finish that meets the requirements is obtained. The surface of the coating is smooth and the average hardness is 56HRC.

The cut samples were corroded with corrosive solution (3% hydrofluoric acid, 6% nitric acid, 91% distilled water), and the corrosion time was 25-30s to prepare metallographic samples, and then the coating was observed by scanning electron microscope (Hitachi-3400). Microstructure, the microstructure of the coating of Example 2, Comparative Example 1 and Comparative Example 2 was detected. As shown in Figures 1 to 3, the particle size of the coating of Example 2 was obviously fine. It can be seen that the multi-component ceramic is relatively fine. Crystal effect is obvious.

Using a microhardness indentation tester, the microhardness of the coatings of Example 2, Comparative Example 1 and Comparative Example 2 was measured from the top of the coating. As shown in Figures 6 and 7, the microhardness of the coating of Example 2 It is significantly higher than that of Control Example 1 and Control Example 2 (A is Example 2, B is Control Example 1, and T3 is Control Example 2).

EDS energy spectrum analyzer was used to detect the coating composition ratio of Example 2 and Comparative Example 1. As shown in Figures 4 and 5, the high melting point alloy elements such as Hf, Ta, Nb and Zr added in the coating of Example 2 were based on From the perspective of adding ratio, considering the measurement error of the instrument, there is almost no burning loss.

The above-mentioned embodiments only represent several embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can also be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims (4)

1. a preparation method of titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating is characterized in that comprising the following steps: (1) Prepare pre-alloyed powder for use; Specific steps include: S1. Take four powders of HfC, TaC, ZrC and NbC with a particle size of 100-270 mesh and mix them in a mass ratio of 1:1:1:1; S2, put the powder mixed by S1 into a high-energy ball mill, and perform ball milling to obtain a ground ceramic phase powder; S3, take spherical titanium alloy powder with a particle size of 400-500 mesh, put the titanium alloy powder and the ceramic phase powder obtained by grinding in S2 into a ball mill for ball milling to obtain a ground pre-alloyed powder; (2) Use industrial alcohol to clean the surface of the substrate to be clad, and then blacken the surface of the substrate; (3) The pre-alloyed powder prepared in step (1) is transported to the surface of the substrate to be cladding treated in step (2) through coaxial powder feeding, and laser cladding is performed to prepare a titanium alloy surface wear-resistant metal-multi-element Ceramic composite modified coating; The process parameters of the laser cladding are as follows: the laser power is 3.5-4.0KW, the rectangular light spot is 2×14 mm, the overlap ratio is 10-30%, the scanning speed is 550-700 mm/min, and the protective gas is argon gas , the powder feeding speed is 1.5～4.5g/s, and the powder feeding air flow is 8L/min. 2. the preparation method of a kind of titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating according to claim 1, is characterized in that: the grinding ball that adopts during described S2 and S3 ball milling is diameter 1mm and 3mm. For corundum balls, the quantity ratio of the two grinding balls is 1:4, the volume ratio of the balls is 3:1, and the ball milling time is 6 to 12 hours. 3. the preparation method of a kind of titanium alloy surface wear-resistant metal-multi-element ceramic composite modified coating according to claim 1, is characterized in that: the mass percentage of ceramic phase powder 5% in the pre-alloyed powder obtained by described S3 ~15%. The method for preparing a titanium alloy surface wear-resistant metal-multi-component ceramic composite modified coating according to claim 1, wherein the titanium alloy surface wear-resistant metal-multi-component ceramic obtained in the step (3) The thickness of the composite modified coating is 0.6-1.2 mm.

Images