CN112144004A - A kind of blade tip wear-resistant cutting coating with saturated mosaic structure and preparation method thereof - Google Patents

Abstract

The invention discloses a blade tip anti-wear cutting coating with a saturated mosaic structure and a preparation method thereof, belonging to the technical field of material surface modification and coating. The bonding alloy is bonded to the blade tip surface, and the bonding alloy layer forms a strong metallurgical bond with the blade tip alloy, and tightly wraps the hard ceramic particles. The hard ceramic particles of the coating are sharply exposed and firmly bonded to the blade tip surface. . The saturated damascene structure enables the coating to have good bonding strength on the premise of ultra-high hardness. The outer edges and corners of the coating are sharp, which can be used to quickly cut the wearable sealing coating to prevent the blade tip from heating up violently.

Description

A kind of blade tip wear-resistant cutting coating with saturated mosaic structure and preparation method thereof

technical field

The invention belongs to the technical field of material surface modification and coating, and in particular relates to a blade tip wear-resistant cutting coating with a saturated mosaic structure and a preparation method thereof.

Background technique

High-performance aero-engines have higher requirements for efficiency and safety, and the size of the gap between the casing and the blade tip is a key factor affecting the performance of the engine. To ensure the high efficiency of the engine, the clearance should not be too large. If the clearance is too small, factors such as centrifugal and surge during engine operation will cause the blade tip to rub against the inner wall of the casing and damage the blade tip. Therefore, sealing technology is often used to improve efficiency and protect the blade tip. That is, a layer of wearable sealing coating is prepared on the inner wall of the engine casing, and a layer of wear-resistant coating is prepared on the blade tip, and the two coatings cooperate with each other to form a suitable gap.

The wear-resistant coating of the blade tip is often made of metal-based ceramic composite materials, and the ceramic particles are fixed on the tip surface of the blade through the alloy binder phase, thereby improving the hardness and wear resistance of the blade tip. At present, the commonly used preparation methods of blade tip wear-resistant coatings are laser cladding technology and electroplating method. The blade tip coating prepared by laser cladding technology can greatly improve the hardness and wear resistance of the substrate, but there is a problem of serious thermal damage to the substrate. The thickness of the blade tip coating prepared by electroplating can be effectively controlled, but the bonding strength between the coating and the substrate is not high, and the coating is easy to fall off.

The engine speed can reach 50000r/min, and the blade tip cutting coating and the abradable coating rub against each other at a great relative speed to generate huge heat, resulting in the sharp heating of the blade tip. Due to the poor wear resistance of the blade tip material itself, it is easy to rub against the abradable coating during service, and simply improving the hardness and wear resistance of the blade tip cannot protect the blade tip.

SUMMARY OF THE INVENTION

In order to solve the technical problem of serious heat generation when the blade tip cutting coating and the abradable sealing coating are rubbed at high speed, the present invention proposes a blade tip anti-wear cutting coating with a saturated mosaic structure and a preparation method thereof. When the coating has a cutting effect on the abradable coating, it can effectively reduce frictional heat generation and reduce the heating rate of the blade tip, thereby preventing blade tip wear.

In order to achieve the above object, the present invention adopts the following technical solutions to be realized:

The invention discloses a blade tip wear-resistant cutting coating with a saturated mosaic structure, which is characterized in that it is composed of hard ceramic particles and a bonding alloy layer, and the hard ceramic particles are discretely distributed and bonded on the blade through the bonding alloy layer. On the end face of the tip base, the bonding alloy layer forms a firm metallurgical bond with the alloy of the blade tip base, and wraps 0.5-0.9 times the height of the hard ceramic particles itself, forming the sharp exposed edges and corners of the hard ceramic particles, which are closely connected with the blade tip. The end face of the base body is combined with a strong anti-wear cutting coating on the blade tip.

A further improvement of the present invention is that the hard ceramic particles are preferably cubic boron nitride particles.

A further improvement of the present invention is that the hard ceramic particles are preferably diamond particles.

A further improvement of the present invention is that the average particle size of the hard ceramic particles is preferably 50-120 μm, which meets the requirements of cutting performance.

A further improvement of the present invention is that the average particle size of the hard ceramic particles is preferably 121-350 μm, which meets the requirements of heat dissipation performance.

A further improvement of the present invention is that the hard ceramic particles with sharp corners facing outwards refer to the exposed surfaces whose smallest directional dimension of a single particle exceeds 0.05 times the average particle size of the particles, and the angle with the outer normal of the blade tip surface is all 0 -60°. Wherein, the minimum directional size refers to the smallest size of the particles in different directions. For example, if the up-down size is larger than the left-right size, the minimum directional size refers to the left-right size.

A further improvement of the present invention is that the percentage of the hard ceramic particles with sharp corners facing outward is greater than 50%.

A further improvement of the present invention is that the height difference between the tops of the hard ceramic particles facing the outer normal of the outer surface of the blade tip is not higher than 0.2-0.5 times the average particle size of the particles themselves.

A further improvement of the present invention is that the distribution spacing of the two adjacent ceramic particles is preferably 1-2.5 times the average particle size of the particles themselves, which has a high distribution density and can realize rapid cutting.

A further improvement of the present invention lies in that the distribution spacing of the two adjacent ceramic particles is preferably 3-10 times the average particle size of the particles themselves, and has the ability to sufficiently dissipate heat.

A further improvement of the present invention is that the total molar content of Cr, Al and Si elements in the bonding alloy is not lower than 13% and not higher than 48%.

A further improvement of the present invention lies in that the preferred mass percentage of the bonding alloy is a nickel-based alloy containing more than 53.0% of nickel and 6% to 28% of chromium.

A further improvement of the present invention is that the preferred mass percentage of the bonding alloy composition is a titanium-based alloy containing more than 40% titanium, 18%-30% zirconium, 10%-25% copper, and 5%-10% nickel. .

A further improvement of the present invention is that the melting point of the bonding alloy is lower than 0.9 times the melting point of the blade tip base in Kelvin temperature.

A blade tip anti-wear coating with a saturated mosaic structure and a preparation method thereof, comprising the following steps:

Substrate surface pretreatment: After degreasing and pollution, the oxide layer on the surface of the substrate is removed by pretreatment to improve the bonding force between the bonding alloy layer and the substrate.

Pre-coating the bonding alloy layer: The pre-treated blade tip base surface is coated with a bonding alloy layer, and the thickness of the bonding alloy layer is preferably 0.4-0.8 times the average particle size of the ceramic particles.

Sprinkle hard ceramic particles on the surface of the bonding alloy layer.

Heating and remelting: heating the bonding alloy layer sprinkled with hard particles to make it re-melted, so that the bonding alloy tightly wraps the hard ceramic particles and forms a firm metallurgical bond with the substrate, bonding the alloy layer and the substrate. The bonding strength exceeds 60MPa.

A further improvement of the present invention is that, in the step, the coating method is preferably vacuum plasma spraying, the spraying power is preferably 25-55kW, and the spraying distance is preferably 100-400mm.

A further improvement of the present invention is that, in the steps, the coating method is preferably laser cladding, the welding speed is preferably 6-60 mm/s, the powder feeding method is preferably synchronous coaxial powder feeding, and the powder feeding rate is preferably 10-60 g/min.

A further improvement of the present invention is that, in the step, the heating temperature is preferably 1.02-1.3 times the melting point of the bonding alloy, and is guaranteed to be lower than the melting point of the tip base, and the lower temperature preferably exceeds the difference between the melting point of the tip base and the bonding alloy 0.5 times.

A further improvement of the present invention is that, in the step, the heating method is preferably vacuum furnace heating, the vacuum degree in the furnace is preferably lower than 5×10 ^-2 Pa, the heating rate is preferably 5-10°C/min, and the holding time is preferably 3-30min.

A further improvement of the present invention is that in the step, the heating method is preferably induction heating, the induction current is preferably 20-65A, the heating distance is preferably 2.5-8mm, and the heating time is preferably 2-15s.

Compared with the prior art, the present invention has the following beneficial effects:

The blade tip wear-resistant cutting coating disclosed by the invention distributes the hard ceramic particles discretely and combines them on the blade tip surface through a bonding alloy, the bonding alloy layer and the blade tip alloy form a firm metallurgical bond, and the hard ceramic particles are Tightly wrapped, the hard ceramic particles of the coating have sharply exposed edges and corners and are firmly bonded to the blade tip surface. The saturated damascene structure enables the coating to have good bonding strength on the premise of ultra-high hardness. The outer edges and corners of the coating are sharp, which can be used to quickly cut the wearable sealing coating to prevent the blade tip from heating up violently.

Description of drawings

1 is a structural diagram of a blade tip anti-wear coating with a saturated mosaic structure provided by an embodiment of the present invention;

Among them: 1 is the blade tip base; 2 is the bonding alloy layer; 3 is the hard ceramic particles.

Detailed ways

In order to make those skilled in the art better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only Embodiments are part of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that the terms "first", "second" and the like in the description and claims of the present invention and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used may be interchanged under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

Below in conjunction with accompanying drawing, the present invention is described in further detail:

Referring to FIG. 1, a blade tip wear-resistant cutting coating with a saturated mosaic structure of the present invention is composed of hard ceramic particles 3 and a bonding alloy layer 2, and the hard ceramic particles 3 are discretely distributed and pass through the bonding alloy layer. 2. Combined on the end face of the blade tip base 1, the bonding alloy layer 2 forms a firm metallurgical bond with the alloy of the blade tip base 1, and wraps the hard ceramic particles 3 0.5-0.9 times the height of itself to form hard ceramic particles. The sharp and exposed edges and corners are firmly bonded to the end surface of the blade tip base body 1, and the anti-wear cutting coating of the blade tip is provided.

Example 1

The diamond particles with an average particle size of 50μm are bonded to the end face of the nickel-based superalloy GH4037 blade tip through the Ni71CrSi bonding alloy. The Ni71CrSi bonding alloy layer forms a strong metallurgical bond with the GH4037 blade tip and wraps 0.5 times the height of the diamond particles. , the average distribution spacing of two adjacent ceramic particles is about 500 μm, forming a cutting coating with sharply exposed diamond particles and a firm combination with the tip surface of GH4037 blades. The specific preparation method of the coating comprises the following steps:

1) Pretreatment of the surface of the substrate: The alloy blade made of GH4037 is used as the substrate. First, the substrate is ground with water sandpaper to remove pollution and oil stains. Then, it is placed in an organic solvent for ultrasonic cleaning, dried and placed in a drying dish.

2) Pre-coating bonding alloy layer: The bonding alloy powder is weighed with a precision electronic balance with an accuracy of 0.1 mg, and then a 100 μm thick Ni71CrSi layer is deposited on the end face of the blade substrate by vacuum plasma spraying. The spraying process parameter is current 500A, voltage 50V, powder feeding rate 15g/min, spraying distance 100mm.

3) Sprinkling of hard ceramic particles: A single layer of diamond particles is then sprinkled on the bond alloy layer.

4) Heating and remelting: The Ni71CrSi layer is remelted by heating in a vacuum furnace, forming a metallurgical bond with the GH4037 matrix and the diamond particles. The heating process parameters of the vacuum furnace are the vacuum degree in the furnace 4×10 ^-2 Pa, and the heating rate is 5℃/ min, holding time 3min.

The hardness of the blade tip anti-wear cutting coating prepared in this example is 300-340HV _0.2 , and the bonding strength between the coatings is between 60-65MPa.

Example 2

The diamond particles with an average particle size of 80μm are bonded to the end face of the TC4 tip base through the Ti20Zr25Cu10Ni bonding alloy. The Ti20Zr25Cu10Ni bonding alloy layer forms a firm metallurgical bond with the TC4 tip and wraps 0.5 times the height of the diamond particles. The average distribution spacing of each ceramic particle is about 120 μm, forming a cutting coating with sharply exposed diamond particle edges and corners, which is firmly bonded to the tip surface of the TC4 blade. The specific preparation method of the coating comprises the following steps:

1) Pretreatment of the surface of the substrate: choose the alloy blade of TC4 material as the substrate, first grind the substrate with water sandpaper to remove pollution and oil, then put it in an organic solvent for ultrasonic cleaning, dry it and put it in a drying dish.

2) Pre-coating bonding alloy layer: The bonding alloy is weighed with a precision electronic balance with an accuracy of 0.1 mg, and then a 100 μm thick Ti20Zr25Cu10Ni layer is deposited on the end face of the blade base by a laser cladding process. The process parameter is the cladding speed. 6mm/s, the powder feeding method is synchronous coaxial powder feeding, and the powder feeding rate is 10g/min.

3) Sprinkling of hard ceramic particles: A single layer of diamond particles is then sprinkled on the bond alloy layer. ;

4) Heating and remelting: The Ti20Zr25Cu10Ni layer is remelted by heating in a vacuum furnace, forming a metallurgical bond with the TC4 matrix and the diamond particles. The heating process parameters of the vacuum furnace are the vacuum degree in the furnace 3×10 ^-2 Pa, and the heating rate is 8℃/ min, holding time 15min.

The hardness of the blade tip anti-wear cutting coating prepared in this example is 320-370HV _0.2 , and the bonding strength between the coatings is between 63-68MPa.

Example 3

The diamond particles with an average particle size of 120μm are bonded to the end face of the nickel-based superalloy GH4037 tip body through the Ni71CrSi bonding alloy. The Ni71CrSi bonding alloy layer forms a strong metallurgical bond with the GH4037 blade tip and wraps 0.7 times the height of the diamond particles. , the average distribution distance of two adjacent ceramic particles is about 360 μm, forming a cutting coating with sharply exposed diamond particles and a firm bond with the tip surface of the GH4037 blade. The specific preparation method of the coating comprises the following steps:

1) Pretreatment of the surface of the substrate: The alloy blade made of GH4037 is used as the substrate. First, the substrate is ground with water sandpaper to remove pollution and oil stains. Then, it is placed in an organic solvent for ultrasonic cleaning, dried and placed in a drying dish.

2) Pre-coating bonding alloy layer: The bonding alloy is weighed with a precision electronic balance with an accuracy of 0.1 mg, and then a 200 μm thick Ni71CrSi layer is deposited on the end face of the blade substrate by vacuum plasma spraying, and the spraying process parameter is a current of 600A , Voltage 60V, powder feeding rate 15g/min, spraying distance 200mm.

3) Sprinkling of hard ceramic particles: A single layer of diamond particles is then sprinkled on the bond alloy layer.

4) Heating and remelting: The Ni71CrSi layer is remelted by heating in a vacuum furnace, forming a metallurgical bond with the GH4037 matrix and the diamond particles. The heating process parameters of the vacuum furnace are the vacuum degree in the furnace 1×10 ^-2 Pa, and the heating rate is 10℃/ min, holding time 30min.

The hardness of the blade tip anti-wear cutting coating prepared in this example is 360-410HV _0.2 , and the bonding strength between the coatings is between 61-66MPa.

Example 4

The diamond particles with an average particle size of 150μm are bonded to the tip surface of the TC4 blade through the Ti20Zr25Cu10Ni bonding alloy. The Ti20Zr25Cu10Ni bonding alloy layer forms a firm metallurgical bond with the TC4 blade tip and wraps the diamond particles 0.7 times the height of the two adjacent ceramics. The average distribution spacing of the particles is about 450 μm, forming a cutting coating with sharply exposed diamond particle edges and corners, which is firmly bonded to the tip surface of the TC4 blade. The specific preparation method of the coating comprises the following steps:

1) Pretreatment of the surface of the substrate: choose the alloy blade of TC4 material as the substrate, first grind the substrate with water sandpaper to remove pollution and oil, then put it in an organic solvent for ultrasonic cleaning, dry it and put it in a drying dish.

2) Pre-coating bonding alloy layer: The bonding alloy is weighed with a precision electronic balance with an accuracy of 0.1 mg, and then a 200 μm thick Ti20Zr25Cu10Ni layer is deposited on the end face of the blade base by the laser cladding process. The process parameter is the cladding speed. 30mm/s, the powder feeding method is synchronous coaxial powder feeding, and the powder feeding rate is 30g/min.

3) Sprinkling of hard ceramic particles: A single layer of diamond particles is then sprinkled on the bond alloy layer. ;

4) Heating and remelting: The Ti20Zr25Cu10Ni layer is remelted by induction heating technology to form a metallurgical bond between the TC4 matrix and the diamond particles. The induction heating process parameters are: induction current 20A, heating distance 2.5mm, heating time 15s.

The hardness of the blade tip anti-wear cutting coating prepared in this example is 350-400HV _0.2 , and the bonding strength between the coatings is between 65-70MPa.

Example 5

The cubic boron nitride particles with an average particle size of 200 μm are bonded to the tip surface of the nickel-based superalloy IN738 through the Ni71CrSi bonding alloy. 0.9 times wrapping, the average distribution distance of two adjacent ceramic particles is about 1000μm, forming a cutting coating with sharply exposed cubic boron nitride particles and strong bonding with the IN738 blade tip surface. The specific method of the coating includes the following steps:

1) Pretreatment of the surface of the substrate: choose the alloy blade of IN738 material as the substrate, first grind the substrate with water sandpaper to remove pollution and oil, then put it into an organic solvent for ultrasonic cleaning, dry it and put it in a drying dish.

2) Pre-coating bonding alloy layer: The bonding alloy is weighed with a precision electronic balance with an accuracy of 0.1 mg, and then a 300 μm thick Ni71CrSi layer is deposited on the end face of the blade base by a vacuum plasma spraying process. The spraying process parameter is current 750A, voltage 70V, powder feeding rate 40g/min, spraying distance 400mm.

3) Sprinkling of hard ceramic particles: A single layer of cubic boron nitride particles is then sprinkled on the bonding alloy layer. ;

4) Heating and remelting: The Ni71CrSi layer is remelted by induction heating technology, forming a metallurgical bond between the IN738 matrix and the cubic boron nitride particles. The induction current is 45A, the heating distance is 5mm, and the heating time is 8s.

The hardness of the blade tip anti-wear cutting coating prepared in this example is 330-360HV _0.2 , and the bonding strength between the coatings is between 66-71MPa.

Example 6

The cubic boron nitride particles with an average particle size of 350μm are bonded to the tip surface of the TC11 blade through the Ti20Zr25Cu10Ni bonding alloy. The Ti20Zr25Cu10Ni bonding alloy layer forms a strong metallurgical bond with the TC11 blade tip and wraps the cubic boron nitride particles 0.9 times the height of the blade. , and the average distribution distance of two adjacent ceramic particles is about 350 μm, forming a cutting coating with sharply exposed cubic boron nitride particles and sharply exposed edges and corners of the TC11 blade tip surface. The specific preparation method of the coating comprises the following steps:

1) Substrate surface pretreatment: choose TC11 alloy blade as the substrate, first grind the substrate with water sandpaper to remove pollution and oil, then put it in an organic solvent for ultrasonic cleaning, dry it and put it in a drying dish.

2) Pre-coating bonding alloy layer: The bonding alloy is weighed with a precision electronic balance with an accuracy of 0.1 mg, and then a 300 μm thick Ti20Zr25Cu10Ni layer is deposited on the end face of the blade base by the laser cladding process. The process parameter is the cladding speed. 60mm/s, the powder feeding method is synchronous coaxial powder feeding, and the powder feeding rate is 60g/min.

3) Sprinkling of hard ceramic particles: A single layer of cubic boron nitride particles is then sprinkled on the bonding alloy layer. ;

4) Heating and remelting: The Ti20Zr25Cu10Ni layer is remelted by induction heating technology, forming a metallurgical bond between the TC11 matrix and the cubic boron nitride particles. The induced current is 65A, the heating distance is 8mm, and the heating time is 2s.

The hardness of the blade tip anti-wear cutting coating prepared in this example is 350-390HV _0.2 , and the bonding strength between the coatings is between 64-70MPa.

The above content is only to illustrate the technical idea of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention all fall within the scope of the claims of the present invention. within the scope of protection.

Claims (10)

1. The blade tip wear-resistant cutting coating with the saturated mosaic structure is characterized by comprising hard ceramic particles (3) and a bonding alloy layer (2), wherein the hard ceramic particles (3) are distributed discretely and are combined on the end face of a blade tip base body (1) through the bonding alloy layer (2), the bonding alloy layer (2) and the alloy of the blade tip base body (1) form firm metallurgical bonding, and the hard ceramic particles (3) are wrapped by 0.5-0.9 time of the height of the hard ceramic particles per se to form the blade tip wear-resistant cutting coating with sharp edges and corners exposed and firm bonding with the end face of the blade tip base body (1).

2. The wear-resistant cutting coating for blade tips with saturated mosaic structure as claimed in claim 1, wherein hard ceramic particles with sharp exposed corners are exposed surfaces with smallest direction size of individual particles exceeding 0.05 times of average particle size, and all have angle between 0-60 ° with the normal of the blade tip base body (1) end surface;

the height difference of the top end of the hard ceramic particles on the side facing the normal outside the outer surface of the blade tip base body (1) is less than 0.2-0.5 times of the average particle size of the particles.

3. The blade tip wear-resistant cutting coating with the saturated mosaic structure according to claim 1, wherein the hard ceramic particles meet the cutting performance requirement when the average particle size is 50-120 μm; when the average grain diameter of the hard ceramic grains is 121-350 mu m, the heat dissipation performance requirement is met.

4. The blade tip wear-resistant cutting coating with the saturated mosaic structure according to claim 1, wherein when the distribution distance between two adjacent hard ceramic particles (3) is 1-2.5 times of the average particle size of the hard ceramic particles, the requirement on quick cutting performance is met; when the distribution distance between two adjacent hard ceramic particles (3) is 3-10 times of the average particle size of the hard ceramic particles, the heat dissipation performance requirement is met.

5. The wear resistant cutting coating for blade tips having a saturated mosaic structure of claim 1, wherein the hard ceramic particles exposed with sharp corners comprise more than 50% of the total number of hard ceramic particles.

6. The blade tip wear-resistant cutting coating with a saturated mosaic structure according to claim 1, characterized in that the combined molar content of the elements Cr, Al and Si in the binder alloy layer (2) is 13-48%; the bonding alloy layer (2) is a nickel-based alloy with the nickel content of more than 53.0 percent and the chromium content of 6 to 28 percent; or selecting titanium-based alloy with titanium content more than 40%, zirconium content 18% -30%, copper content 10% -25% and nickel content 5% -10%.

7. The blade tip wear-resistant cutting coating with a saturated mosaic structure according to claim 1, characterized in that the melting point of the binder alloy is lower than 0.9 times the melting point of the blade tip substrate (1) calculated as kelvin temperature.

8. The method for preparing a blade tip wear resistant cutting coating with a saturated mosaic structure of claim 1, comprising the steps of:

1) coating a bonding alloy layer: coating a bonding alloy layer (2) on the surface of the cleaned blade tip substrate (1);

2) spreading hard ceramic particles (1) on the surface of the bonding alloy layer (2);

3) heating and remelting: and heating the bonding alloy layer scattered with the hard particles to re-melt the bonding alloy layer, so that the bonding alloy wraps the hard ceramic particles (1) tightly and forms firm metallurgical bonding with the blade tip base body (1), and the bonding strength of the bonding alloy layer (2) and the blade tip base body (1) exceeds 60 MPa.

9. The method for preparing the blade tip wear-resistant cutting coating with the saturated mosaic structure as claimed in claim 8, wherein in the step 1), the bonding alloy layer is coated by a vacuum plasma spraying method or a laser cladding method; wherein:

the spraying power of the vacuum plasma spraying method is 25-55k, and the spraying distance is 100-400 mm;

the cladding speed of the laser cladding method is 6-60mm/s, the powder feeding mode is synchronous coaxial powder feeding, and the powder feeding rate is 10-60 g/min.

10. The method for preparing the blade tip wear-resistant cutting coating with the saturated mosaic structure as claimed in claim 8, wherein in the step 3), the temperature for heating and remelting is 1.02-1.3 times of the melting point of the bonding alloy, and the temperature is lower than 0.5 times of the difference between the melting points of the blade tip substrate (1) and the bonding alloy;

heating and remelting adopt vacuum heating or induction heating;

vacuum degree of vacuum heat treatment is less than 5 × 10^-2Pa, the heating rate is 5-10 ℃/min, and the heat preservation time is 3-30 min;

the induction current of the induction heating treatment is 20-65A, the heating distance is 2.5-8mm, and the heating time is 2-15 s.

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