CN114836666B - High-entropy alloy composite coating for improving surface hardness and wear resistance of metal substrate and processing method - Google Patents

Abstract

The invention discloses a high-entropy alloy composite coating for improving the surface hardness and wear resistance of a metal substrate and a processing method thereof, wherein a diamond grinding layer comprises a high-entropy alloy component and diamond powder, the high-entropy alloy component comprises Fe, co, cr, ni, al, ti and Si element which is the same as carbon, carburization from diamond to an alloy interface area occurs at the contact interface of the high-entropy alloy and diamond powder particles, a SiC high-hardness structure is formed between diamond surface carbon and silicon, hard metal silicide is formed between Si and other alloys, and diamond surface atoms are firmly combined with alloy contact surfaces in an atomic layer by virtue of the transition element characteristics of Si, so that the fixing strength of diamond particles is improved. The diamond-enhanced FeCoCrNiAlTiSi high-entropy alloy composite coating prepared by the laser cladding process has continuous and smooth surface, fewer surface defects, better combination between the coating and a metal substrate, no air holes and shrinkage porosity defects in the coating, good tissue compactness and remarkable improvement on wear resistance.

Description

A high-entropy alloy composite coating for improving the surface hardness and wear resistance of metal substrates and processing method

technical field

The invention belongs to the field of wear-resistant materials, and in particular relates to a high-entropy alloy composite coating and a processing method for improving the surface hardness and wear resistance of metal substrates.

Background technique

Diamond is a high-hardness material and is often used in the surface strengthening of various wear-resistant structures. Especially for the surface of super wear-resistant materials, diamond strengthening can greatly enhance the wear strength of materials and improve the service life of equipment. In the existing diamond wear-resistant layer process, a two-step method is generally used to process the diamond coating. First, the laser melts the metal in the surface processing area of the component to form a metal laser molten pool. Then, the diamond powder is added to the metal laser molten pool to solidify, and the obtained diamond film.

However, there are many significant defects in this process. First of all, due to the high viscosity of the metal liquid inside the molten pool, the depth of diamond embedding is insufficient, and many diamond powders cannot form a firm adhesion surface, which is easy to fall off, resulting in a longer service life of the diamond layer. short.

Secondly, this structure is essentially a layered structure between the diamond layer and the metal layer. No matter what kind of processing technology can only produce a single layer of thin wear-resistant area, the wear resistance of the processed product will decline seriously in the later stage.

Third, the surface layer of the diamond is regularly arranged in a three-dimensional network of carbon atoms, and the metal crystals in the contacted metal interface are only "contacted" rather than "bonded". The diamond particles are still wrapped and fixed by the metal cavity, and after a period of use Finally, once the cavity expands, the diamond particles will fall off, thus losing the wear resistance.

Therefore, although the diamond wear-resistant layer has made considerable technical progress in the field of industrial applications, there is still a lot of room for improvement in how to better improve the wear resistance and exert the diamond wear-resistant effect.

Contents of the invention

The high-entropy alloy composite coating and processing method for improving the surface hardness and wear resistance of metal substrates can improve the bonding strength between diamond particles and metal substrate materials, and effectively improve the wear resistance of the diamond layer.

The present invention is achieved through the following technical solutions:

A high-entropy alloy composite coating used to improve the surface hardness and wear resistance of metal substrates, including high-entropy alloys and diamond powder, the expression of high-entropy alloys is Fe _a Co _b Cr _c Ni _d Al _e Ti _{f Sig} , high Carburization from diamond to alloy interface occurs at the contact interface between entropy alloy and diamond powder particles.

Preferably, the atomic ratio a-f in the high-entropy alloy is 1:0.5-1.5:1.1-2.1:0.5-1.4:0.1-1.0:0.2-1.1:0.1-0.8. In a preferred mode of the present invention, the ratio of a-f is 1:1:1:1:0.5:0.5:0.2.

Preferably, the diamond powder accounts for 0.1-15wt% of the high-entropy alloy.

Furthermore, the diamond powder accounts for 3wt%-15wt% of the high-entropy alloy, more preferably, 10wt%-12wt%.

Preferably, the average particle size of the diamond powder is 50-80 μm.

A processing method for a high-entropy alloy composite coating for improving the surface hardness and wear resistance of a metal substrate, comprising the following steps:

a. Metal substrate pretreatment: Grinding the metal substrate, removing burrs, polishing the surface, removing the oxide film on the surface, and then ultrasonically cleaning and drying;

b. Pre-coating: Mix pure Fe, Co, Cr, Ni, Al, Ti, Si powder, diamond powder and binder, coat on the surface of the metal substrate, and obtain a coating on the surface after drying metal substrate;

c. Laser cladding: place the above-mentioned metal substrate with the coating on its surface in an inert gas, preferably inert, the gas is argon, the filling amount is 0.13-0.37dm ³ , and the laser cladding head is used as the energy source. Adopt positive defocusing method, act vertically on the coating surface, preferably, control the defocusing amount of the laser cladding head to 30-50mm, and laser power to 1000-2000W, so as to promote the occurrence of Carburized and strengthened to form a diamond grinding layer.

It should be noted that in this technical solution, carburization between diamond carbon and alloy metal components can strengthen the hardness of the alloy, and at the same time, the carburizing microstructure and Si elements form a mixed composition of SiC and metal silicate, and the diamond particles and alloy firmly combined.

Preferably, in a, the metal substrate is one of a titanium alloy metal substrate, an aluminum alloy metal substrate or a stainless steel metal substrate, preferably, the titanium alloy substrate is a TC4 titanium alloy substrate, and the stainless steel substrate is 304 Stainless steel base.

Preferably, in b, the average particle size of the pure Fe, Co, Cr, Ni, Al, Ti, Si powder is 35-50 μm, the average particle size of the diamond powder is 50-80 μm, the quality of the binder The mass of the mixture formed by the pure Fe, Co, Cr, Ni, Al, Ti, Si powder and diamond powder is 20 to 35 wt%, and the binder is diacetone alcohol solution of cellulose acetate with a concentration of 4.2 -4.3g/100mL.

Preferably, in c, the thickness of the diamond grinding layer is 0.1-1.5mm, the scanning speed of the laser cladding is 8-12mm/s; the delivery pressure of the inert gas is controlled to be 0.05-0.15MPa.

Beneficial effect:

1. The main component of diamond is simple carbon. In this technical solution, simple silicon is added. A SiC high-hardness structure is formed between carbon and silicon on the surface of the diamond, and a hard metal silicide is formed between Si and other alloys. Relying on the transition element characteristics of Si in At the atomic level, the atoms on the surface of the diamond are firmly combined with the contact surface of the alloy to improve the fixation strength of the diamond particles;

2. Diamond powder and metal powder are blended and processed. By adjusting the laser intensity, the carbonization of the diamond is avoided, and the carbonization of the metal surface in contact with the diamond is promoted, the hardness of the metal at the contact surface is improved, and the firmness of the diamond particles is improved;

3. The cemented carbide composed of Fe, Co, Cr, Ni, Al, Ti, Si is compatible with the hardness of diamond, which not only ensures the firmness of diamond, but also ensures that the alloy itself has sufficient hardness and willfulness to ensure the installation of diamond Strength and structural strength of the overall alloy, with diamond as the strengthening phase, the hardness of the coating is greatly improved compared with the metal substrate, and the wear resistance is significantly improved;

4. The surface of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding is continuous and smooth, with few surface defects, good bonding between the coating and the metal substrate, and no defects such as pores and shrinkage porosity inside the coating. Good compactness;

5. The processing method is simple and the controllability is good. The microhardness and wear resistance of the prepared diamond-enhanced high-entropy alloy composite coating have been significantly improved, which is beneficial for the composite coating to adapt to more complex and harsh working environments. , has a good application prospect.

Description of drawings

Fig. 1. compares the microhardness figure of the diamond-enhanced high-entropy alloy composite coating prepared in comparative example, embodiment 1-14;

Figure 2. Comparison of wear resistance of diamond-enhanced high-entropy alloy composite coatings prepared in Comparative Examples and Examples 1-14.

Detailed ways

The following examples will further illustrate the present invention, but do not limit the present invention thereby.

Prepared sample hardness test method in the embodiment:

The cross-section of the diamond-enhanced high-entropy alloy composite coating sample was inlaid and polished, and the microhardness of the coating cross-section was measured with a HX-1000 micro-Vickers hardness tester. The applied load was 200g, and the loading time was 15s;

Select 5 points evenly on the surface of each cladding sample (keep a certain distance between points), and take the average value after testing the hardness value;

Its working principle is to press the diamond indenter into the surface of the material to be tested by loading a certain value of load, load it for a certain period of time, and then measure the approximate diamond-shaped imprint left on the surface of the sample after unloading, and measure the diagonal of the indentation. The indentation area is obtained by the length, and then the microhardness of the material can be obtained by calculating the ratio of the loading load to the indentation area;

The indenter for the microhardness test uses a regular tetrahedral pyramidal diamond indenter with an included angle of 136°. The formula for calculating the Vickers hardness value is as follows:

In the formula: F——load/kgf;

S - indentation surface area;

α——the angle between the opposite faces of the indenter = 136°;

d - average indentation diagonal length;

HV - Vickers hardness value.

Prepared sample abrasion resistance test method in the embodiment:

The wear resistance of the high-entropy alloy composite coating of the present invention is measured by a multi-functional friction and wear testing machine. The test conditions are: load 50N, rotating speed 100r/min, wear scar radius 3mm, time 30min, motion mode is ball-on-disk type, The material of the grinding head is Si3N4; before and after the test, use the analytical balance to weigh and calculate the amount of wear.

Comparative example:

In order to compare with the following examples 1-13, the surface of the metal substrate in the comparative example is Fe _a Co _b Cr _c Ni _d Al _e Ti _{f Sig} high entropy alloy coating, without adding diamond reinforcement phase, the specific processing method is as follows :

Using a TC4 titanium alloy substrate, the base material is processed into a plate-shaped sample block of 30mm×20mm×6mm, and then the plate-shaped sample block is polished to remove burrs and oxide films on the surface, cleaned with ultrasonic acetone, and then dried; Binder Brush dry pure Fe, Co, Cr, Ni, Al, Ti, Si powder evenly on the sample surface, in high entropy alloy: a=1, b=1, c=1, d=1, e=0.5, f=0.5, g=0.2. Brushing thickness is 0.8mm. After successful presetting, laser cladding is performed on the coating.

It should be noted that during laser cladding, the laser cladding head can be fixed on its arm through the robot, and the movement of the cladding head can be realized by adjusting the movement of the robot to complete the cladding work.

Using the coating microhardness test method, the microhardness of the above coating was measured to be about 559.3HV, and the wear resistance of the above high entropy alloy coating was measured to be about 6.3mg by using the coating wear resistance test method.

Example 1:

In the present embodiment, the step of a is consistent with the comparative example, using the TC4 titanium alloy substrate, the difference is that steps b and c have been added, and the specific processing method of the composite coating is as follows:

b. In the average particle size of 50 μm pure Fe, Co, Cr, Ni, Al, Ti, Si powder, the diamond powder with an average particle size of 3% is mixed with a mass fraction of 80 μm, and after being uniformly mixed by a ball mill, it is dried, and the ball mill speed is 500r/min. Brush the prepared coating raw material powder with a binder on the surface of the metal substrate that has been removed from the oxide film, the brushing thickness is 0.8mm, the amount of the binder is 20-35wt% of the mass of the above mixture, and the coating is preset After that, clamp and fix it on the workbench.

The binder is cellulose acetate-diacetone alcohol solution. The cellulose acetate-diacetone alcohol solution is prepared by uniformly mixing 200mL diacetone alcohol and 8.5g cellulose acetate in a water bath at 90°C for 10 minutes.

c. As shown in Figure 1, a fiber laser is used as the energy source, and the laser with a power of 1500W acts vertically on the coating surface with a defocus of 45mm. The cladding head moves linearly under the control of the robot, and the scanning speed is 10mm/ s, the delivery direction of the inert gas is parallel to the coating surface, and the delivery rate is 15L/min.

The thickness of the obtained diamond grinding layer is 0.72mm, and the microhardness of the above-mentioned 3% diamond-reinforced FeCoCrNiAlTiSi high-entropy alloy composite coating is measured by the coating microhardness test method to be about 653.2HV. The test method measures that the wear amount of the diamond-enhanced high-entropy alloy composite coating is about 3.7 mg.

Example 2:

This example is basically the same as Example 1, using a TC4 titanium alloy substrate, except that the mass fraction of diamond in this example is 6%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.76mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 825.1HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 3.3 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Example 3:

This example is basically the same as Example 1, using a TC4 titanium alloy substrate, the difference is that the mass fraction of diamond in this example is 9%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.75mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 912.4HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 2.9 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Example 4:

This example is basically the same as Example 1, using a TC4 titanium alloy substrate, the difference is that the mass fraction of diamond in this example is 10%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.86mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 1053.6HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 2.2 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Example 5:

This example is basically the same as Example 1, using a TC4 titanium alloy substrate, the difference is that the mass fraction of diamond in this example is 11%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.85mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 1033.5HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 2.3 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Embodiment 6:

This example is basically the same as Example 1, using a TC4 titanium alloy substrate, the difference is that the mass fraction of diamond in this example is 12%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.84mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 1028.4HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 2.6mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Embodiment 7:

This embodiment is basically the same as Embodiment 1, using 304 stainless steel substrate, the difference is that the mass fraction of diamond in this embodiment is 9%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.53mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 901.2HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 3.8 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Embodiment 8:

This embodiment is basically the same as Embodiment 1, using 304 stainless steel substrate, the difference is that the mass fraction of diamond in this embodiment is 10%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.73mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 1072.9HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 2.5 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Embodiment 9:

This embodiment is basically the same as Embodiment 1, using 304 stainless steel substrate, the difference is that the mass fraction of diamond in this embodiment is 11%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.64mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 1042.1HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 2.7 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Example 10:

This example is basically the same as Example 1, using a 304 stainless steel substrate, the difference is that the mass fraction of diamond in this example is 12%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.61mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 1012.3HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 2.8 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Example 11:

This example is basically the same as Example 1, using an aluminum alloy substrate, except that the mass fraction of diamond in this example is 9%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.73mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 913.4HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 3.6 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Example 12:

This example is basically the same as Example 1, using an aluminum alloy substrate, except that the mass fraction of diamond in this example is 10%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.89mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 1151.4HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 2.1 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Example 13:

This example is basically the same as Example 1, using an aluminum alloy substrate, except that the mass fraction of diamond in this example is 11%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.83mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 1035.1HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 2.4 mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

Example 14:

This example is basically the same as Example 1, using an aluminum alloy substrate, except that the mass fraction of diamond in this example is 12%, and other experimental conditions are the same.

The thickness of the obtained diamond grinding layer is 0.81mm, and the microhardness of the above-mentioned diamond-enhanced high-entropy alloy composite coating is measured by the coating microhardness test method to be about 992.3HV, and the wear resistance test method of the coating is used to measure The wear amount of the above-mentioned diamond-enhanced high-entropy alloy composite coating is about 2.8mg.

Compared with the comparative example, the mechanical properties of the diamond-enhanced high-entropy alloy composite coating prepared by laser cladding in this example are significantly improved.

The results in Figure 1 show that the increase in diamond content can significantly increase the hardness of the cladding layer.

The results in Figure 2 show that with the increase of diamond content, the number of hard particles in the cladding layer increases, the distance between particles decreases, and the protective effect on the bonding phase of the cladding layer is enhanced, thereby reducing the wear and tear of the matrix phase , improve the wear resistance of the cladding layer.

The above is only a specific implementation of the present invention, but the scope of protection of the present invention is not limited thereto, and any changes or replacements that do not come to mind through creative work shall be covered within the scope of protection of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope defined in the claims.

Claims (4)

1. The high-entropy alloy composite coating for improving metal substrate surface hardness and wear resistance is characterized in that, comprising high-entropy alloy and diamond powder, the expression of high-entropy alloy is Fe _a Co _b Cr _c Ni _d Al _e Ti _{f Sig} , carburization from diamond to the alloy interface area occurs at the contact interface between the high-entropy alloy and the diamond powder particles, the diamond powder accounts for 0.1wt%-15wt% of the high-entropy alloy, and the average particle size of the diamond powder is 50 -80μm; the atomic percentage in the high-entropy alloy is a:b:c:d:e:f:g= 1: 0.5～1.5:1.1～2.1:0.5～1.4:0.1～1.0:0.2～1.1:0.1～0.8; A processing method for a high-entropy alloy composite coating, comprising the following steps: a, metal substrate pretreatment: the metal substrate is polished to remove burrs, polish the surface, remove the oxide film on the surface, and then ultrasonically clean and dry; b. Pre-coating: Mix pure Fe, Co, Cr, Ni, Al, Ti, Si powder, diamond powder and binder, coat on the surface of the metal substrate, and dry the coated surface metal substrate; c. Laser cladding: place the metal substrate with the coating on the above surface in an inert gas, use the laser cladding head as the energy source, and adopt a positive defocusing method to act vertically on the coating surface to promote the diamond powder on the surface The contact surface with the high-entropy alloy is carburized and strengthened to form a diamond grinding layer; Wherein: in c, the thickness of the diamond grinding layer is 0.1-3 mm, the scanning speed of the laser cladding head is 8-12 mm/s; the delivery pressure of the inert gas is controlled at 0.05-0.15 MPa, The inert gas is argon, the filling amount is 0.13-0.37dm ³ , the defocusing amount of the laser cladding head is controlled to be 30-50mm, and the laser power is 1000-2000W. 2. the processing method for improving the high-entropy alloy composite coating of metal substrate surface hardness and wear resistance described in claim 1, is characterized in that, comprises the following steps: a, metal substrate pretreatment: the metal substrate is polished to remove burrs, polish the surface, remove the oxide film on the surface, and then ultrasonically clean and dry; b. Pre-coating: Mix pure Fe, Co, Cr, Ni, Al, Ti, Si powder, diamond powder and binder, coat on the surface of the metal substrate, and dry the coated surface metal substrate; c. Laser cladding: place the metal substrate with the coating on the above surface in an inert gas, use the laser cladding head as the energy source, and adopt a positive defocusing method to act vertically on the coating surface to promote the diamond powder on the surface The contact surface with the high-entropy alloy is carburized and strengthened to form a diamond grinding layer; Wherein: in c, the thickness of the diamond grinding layer is 0.1-3 mm, the scanning speed of the laser cladding head is 8-12 mm/s; the delivery pressure of the inert gas is controlled at 0.05-0.15 MPa, The inert gas is argon, the filling amount is 0.13-0.37dm ³ , the defocusing amount of the laser cladding head is controlled to be 30-50mm, and the laser power is 1000-2000W. 3. The processing method according to claim 2, characterized in that, in a, the metal substrate is one of a titanium alloy metal substrate, an aluminum alloy metal substrate or a stainless steel metal substrate. 4. processing method according to claim 2 is characterized in that, in b, the average particle size of described pure Fe, Co, Cr, Ni, Al, Ti, Si powder is 35-50 μ m, and the average grain size of described diamond powder The average particle size is 50-80 μm, the mass of the binder accounts for 20-35wt% of the mass of the mixture formed by the pure Fe, Co, Cr, Ni, Al, Ti, Si powder and diamond powder, the binder It is diacetone alcohol solution of cellulose acetate, the concentration is 4.2-4.3g/100mL.