Ni3Al-based alloy powder for laser cladding of copper alloy surface, cladding layer and preparation method of Ni3Al-based alloy powder

Abstract

The invention relates to Ni3Al-based alloy powder for laser cladding of a copper alloy surface, a cladding layer and a preparation method of the Ni3Al-based alloy powder, belongs to the technical field of laser processing materials, and is used for solving at least one of the problems of poor abradability, low hardness, low interfacial shear strength and the like of an existing copper alloy cladding layer. The Ni3Al-based alloy powder comprises the following chemical components in percentage by mass: 6.6%-7.1% of Al, 3.0%-3.5% of C, 34.5%-37.5% of Cr, 0.041%-0.06% of B, less than or equal to 200ppm of O, less than or equal to 30ppm of N, less than or equal to 5ppm of H and the balance of Ni. By adopting the Cr7C3 reinforced Ni3Al-based alloy powder provided by the invention, a cladding layer which is compact in organization structure, high in bonding strength with a matrix and excellent in wear resistance can be directly prepared on the copper surface. Specifically, the average hardness of a cladding layer on the surface of the copper alloy is larger than or equal to 490 HV, the shear strength of an interface is larger than or equal to 350 MPa, and under the dry friction condition (point friction and opposite grinding materials are Si3N4), the room-temperature wear rate is smaller than or equal to 1.85 * 10 <-5 > mm < 3 > / (N.m), and the wear rate at the temperature of 300 DEG C is smaller than or equal to 2.00 * 10 <-5 > mm < 3 > / (N.m).

Description

Technical Field

[0001] The present invention relates to the technical field of laser processing materials, and in particular to a Ni 3 Al-based alloy powder, cladding layer and preparation method thereof. Background Art

[0002] Copper alloys play an important role in many industrial fields due to their excellent thermal conductivity, electrical conductivity and corrosion resistance, and are widely used in aerospace, electrical engineering and metallurgical equipment. The copper plate of the crystallizer is a key equipment in the continuous casting production process. During the working process, under the combined action of high-temperature molten steel and low-temperature cooling water, it is subjected to high-temperature oxidation, chemical corrosion, surface wear and thermal fatigue. The existence of these problems will not only shorten its service life, but also may cause significant economic losses to industrial production and manufacturing. At present, surface treatment technology is used to prepare high-temperature wear-resistant coatings on the surface of copper alloys, which effectively improves the performance of copper alloys and prolongs their service life. Among the many surface modification technologies, laser cladding technology has become one of the preferred methods to improve the surface performance of crystallizer copper plates due to its unique advantages.

[0003] Since copper alloys and various cladding materials have significant differences in key physical properties such as thermal expansion coefficient, melting point and density, as well as metallurgical compatibility, the cladding process may cause poor interface bonding and stress concentration, which in turn leads to problems such as peeling and crack formation of the cladding layer. In order to solve this problem, a Ni-based transition layer is generally introduced between the copper alloy and the wear-resistant cladding layer, and the good metallurgical compatibility of the Ni-based material with the copper alloy and the cladding material is utilized to achieve a better combination of the cladding layer and the copper alloy. However, the method of using a transition layer not only increases the production cost, but most importantly increases the thickness of the cladding layer, which reduces the overall thermal conductivity of the crystallizer copper plate, so there are certain limitations. Therefore, it is urgent to develop high-temperature wear-resistant cladding materials with good metallurgical compatibility with copper alloys. Summary of the invention

[0004] In view of the above analysis, the present invention aims to provide a Ni 3 Al-based alloy powder, cladding layer and preparation method thereof are used to solve at least one of the problems of poor wear resistance, low hardness and low interface shear strength of existing copper alloy cladding layers.

[0005] In a first aspect, the present invention provides a Ni 3 Al-based alloy powder, characterized in that the Ni 3The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 6.6% to 7.1%, C: 3.0% to 3.5%, Cr: 34.5% to 37.5%, B: 0.041% to 0.06%, O≤200ppm, N≤30ppm, H≤5ppm, and the balance is Ni.

[0006] Furthermore, the Ni 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3 , the mass content of carbides is 33% to 38%.

[0007] Furthermore, the Ni 3 The atomic ratio of nickel equivalent to aluminum equivalent of the Al-based alloy powder is 3.2 to 3.45.

[0008] In a second aspect, the present invention provides a copper alloy surface cladding layer, wherein the cladding layer is made of the above-mentioned Ni 3 Al-based alloy powder is prepared.

[0009] In a third aspect, the present invention provides a method for preparing the above-mentioned copper alloy surface cladding layer, comprising the following steps:

[0010] Step 1: pretreating the surface of the copper alloy substrate;

[0011] Step 2: Set the cladding track, which can be unidirectional or reciprocating;

[0012] Step 3: preheating the pretreated copper alloy substrate;

[0013] Step 4: Use coaxial powder feeding method to feed Ni 3 Al-based alloy powder is conveyed to the surface of the preheated copper alloy substrate;

[0014] Step 5: Use laser cladding method to 3 The Al-based alloy powder is clad on the surface of the copper alloy substrate to form a cladding layer.

[0015] Furthermore, in step 1, the pretreatment includes roughening treatment and de-impurity treatment.

[0016] Furthermore, in step 3, the preheating temperature in the preheating treatment is 150°C to 300°C.

[0017] Further, in step 4, the Ni 3 The particle size of the Al-based alloy powder is 53 μm to 125 μm, and the coaxial powder feeding rate is 5 g / min to 15 g / min.

[0018] Furthermore, in step 5, the cladding process parameters in the laser cladding method are: laser power 5000W to 8000W, scanning speed 0.15m / min to 0.45m / min, and shielding gas is argon.

[0019] In a fourth aspect, the present invention provides a Ni 3 Application of Al-based alloy powder in surface modification of continuous casting mold copper plates in the metallurgical field.

[0020] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0021] (1) The present invention reduces the aluminum content and increases the nickel content, thereby increasing the nickel-aluminum equivalent atomic ratio and promoting the formation of the γ-Ni phase, so that the alloy powder laser cladding layer Ni 3 Al phase and γ-Ni phase, using γ-Ni phase to achieve good metallurgical bonding between cladding layer and copper alloy;

[0022] (2) In order to achieve a good metallurgical bonding between the cladding layer and the copper alloy, the present invention reduces the Ni 3 The aluminum content of Al-based alloy powder is increased, the nickel content is increased, and the microstructure of the cladding layer is mainly Ni 3 Al phase, γ-Ni phase and carbide;

[0023] (3) Using the Cr provided by the present invention 7 C 3 Enhanced Ni 3 Al-based alloy powder can be directly prepared on the copper surface to obtain a cladding layer with dense structure, high bonding strength with the substrate and excellent wear resistance. Specifically, the average hardness of the copper alloy surface cladding layer is ≥490HV, the shear strength of the interface is ≥350MPa, and under dry friction conditions (point friction, the grinding material is Si 3 N 4 ), the room temperature wear rate is ≤1.85×10 -5 mm 3 / (N·m), wear rate at 300℃≤2.00×10 -5 mm 3 / (N·m).

[0024] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0026] Figure 1 The macroscopic morphologies of three groups of single-pass laser cladding layers prepared in Example 1 of the present invention;

[0027] Figure 2 The macroscopic morphology of the cladding layer prepared by preheating the copper alloy to 200° C. in Example 1 of the present invention;

[0028] Figure 3 The bonding interface morphology of the cladding layer and the substrate prepared by preheating the copper alloy to 200° C. in Example 1 of the present invention;

[0029] Figure 4 This is a microstructure diagram of the cladding layer prepared by preheating the copper alloy to 200° C. in Example 1 of the present invention;

[0030] Figure 5 This is the bonding interface morphology between the cladding layer prepared in Comparative Example 1 of the present invention and the substrate. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0032] A specific embodiment of the present invention discloses a Ni 3 Al-based alloy powder, the Ni 3 The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 6.6% to 7.1%, C: 3.0% to 3.5%, Cr: 34.5% to 37.5%, B: 0.041% to 0.06%, O≤200ppm, N≤30ppm, H≤5ppm, and the balance is Ni.

[0033] Preferably, the Ni 3 The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 6.6% to 6.8%, C: 3.1% to 3.3%, Cr: 35.5% to 36.5%, B: 0.045% to 0.055%, O≤160ppm, N≤30ppm, H≤5ppm, and the balance is Ni.

[0034] It should be noted that usually Ni 3 The nickel-aluminum equivalent atomic ratio of the Al phase is 3. The present invention reduces the aluminum content and increases the nickel content, thereby increasing the nickel-aluminum equivalent atomic ratio and promoting the formation of the γ-Ni phase, so that the alloy powder laser cladding layer Ni 3Al phase and γ-Ni phase, using γ-Ni phase to achieve good metallurgical bonding between cladding layer and copper alloy. 3 The Al content in the Al-based alloy powder is selected to be 6.6% to 7.1%, so that the atomic ratio of the nickel equivalent to the aluminum equivalent of the alloy powder is 3.2 to 3.45. 3 The Al content in the Al-based alloy powder is selected to be 6.6% to 6.8%, so that the atomic ratio of the nickel equivalent to the aluminum equivalent of the alloy powder is 3.3 to 3.4.

[0035] It should be noted that in order to achieve a good metallurgical bonding between the cladding layer and the copper alloy, the Ni 3 The aluminum content of Al-based alloy powder is increased, the nickel content is increased, and the microstructure of the cladding layer is mainly Ni 3 Al phase, γ-Ni phase and carbide. Ni 3 Al phase hardness 300 ~ 400HV, γ-Ni phase hardness 190 ~ 215HV, Cr 7 C 3 The hardness of the type carbide exceeds 1200HV, so the presence of γ-Ni phase reduces the wear resistance and microhardness of the cladding layer. In order to maintain the good wear resistance of the cladding layer, Ni 3 Al-based alloy powder needs to contain a higher proportion of carbides. Since some C and Cr elements are dissolved in Ni 3 Al phase, so Ni 3 The C content in the Al-based alloy powder is selected to be 3.0% to 3.5%, and the Cr content is selected to be 34.5% to 37.5%, so that the carbide content of the alloy powder is 33% to 38%. 3 The C content in the Al-based alloy powder is selected to be 3.1% to 3.2%, and the Cr content is selected to be 35.5% to 36.5%, so that the carbide content of the alloy powder is 34% to 36%.

[0036] It should be noted that Ni 3 Al alloys are brittle at room temperature, and a small amount of B can increase Ni 3 The room temperature ductility of Al inhibits crack formation, but when the B element is excessive, B is enriched on the grain boundaries and promotes the formation of hot cracks. 3 Within the chemical composition range of Al-based alloy powder, when the B content is less than 0.04%, it cannot improve the Ni 3 The role of Al plasticity, and when the B content is higher than 0.06%, the cladding layer has a greater tendency to thermal cracks. The B content of the present invention is determined to be 0.041% to 0.06%, which can not only ensure the Ni cladding layer 3 The Al-based phase has room temperature ductility and can inhibit the formation of hot cracks. 3The B content of the Al-based alloy powder is preferably 0.045% to 0.055%.

[0037] It should be noted that Ni 3 During the laser cladding process of Al-based alloy powder, impurity elements such as O, H, and N will participate in the metallurgical reaction. 3 When the O content of Al-based alloy cladding layer is excessive, fatigue problems are prone to occur and the wear amount increases; when the N content is too high, AlN is easily formed and the crack tendency increases; when the H content is too high, the brittleness of the cladding layer is increased. The limit value of the impurity element content has extremely important engineering value and determines the metallurgical process technology and economy of the powder material. The present invention limits the content of O, N, and H elements in the powder to ≤200ppm, ≤30ppm, and ≤5ppm. Furthermore, Ni 3 The O content of the Al-based alloy powder is limited to ≤160 ppm.

[0038] Specifically, the Ni 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3 The mass content of carbide is 33% to 38%, for example, 33.5%, 34%, 34.5%, 35%, 35.5%, 36%, 36.5%, 37%, and 37.5%.

[0039] It should be noted that the finely dispersed Cr 7 C 3 The hard phase plays a supporting role, separates the friction surfaces, reduces the direct interaction between the friction pairs, and significantly improves the wear resistance. 3 The mass content of carbides in the Al-based alloy powder is 33% to 38%, which makes the cladding layer have good wear resistance and forming quality. When the mass content of carbides is less than 33%, there are fewer high-hardness carbide strengthening phases. Due to the presence of a certain proportion of γ-Ni phase in the cladding layer, the overall hardness of the cladding layer is insufficient, resulting in a decrease in the wear resistance of the cladding layer; when the mass content of carbides is higher than 38%, the crack tendency of the cladding layer increases, the degree of bonding with the copper alloy decreases, and the cladding forming quality is poor.

[0040] The Cr provided by the present invention is used 7 C 3 Enhanced Ni 3 Al-based alloy powder can be directly prepared on the copper surface to obtain a cladding layer with dense structure, high bonding strength with the substrate and excellent wear resistance.

[0041] Preferably, the Ni 3The mass content of carbides in the Al-based alloy powder is 34% to 36%.

[0042] Specifically, the Ni 3 The atomic ratio of nickel equivalent to aluminum equivalent of the Al-based alloy powder is 3.2 to 3.45, for example, 3.25, 3.30, 3.35, or 3.40.

[0043] It should be noted that when the atomic number ratio of nickel equivalent to aluminum equivalent is less than 3.2, the proportion of γ-Ni phase is insufficient, and it is difficult to achieve a good metallurgical bonding between the cladding layer and the copper alloy; when the atomic number ratio of nickel equivalent to aluminum equivalent is greater than 3.45, the proportion of γ-Ni phase is large, resulting in a significant decrease in the wear resistance of the cladding layer.

[0044] Preferably, the Ni 3 The atomic ratio of nickel equivalent to aluminum equivalent of the Al-based alloy powder is 3.3 to 3.4.

[0045] It should be noted that in the present invention, the calculation principle of the number of nickel equivalent atoms is:

[0046]

[0047] Where Ni represents Ni 3 The mass percentage of Ni element in Al-based alloy powder, Cr Ni3Al溶 It is 3% to 7%.

[0048] The calculation principle of aluminum equivalent atomic number is:

[0049]

[0050] Among them, Al represents Ni 3 The mass percentage of Al element in Al-based alloy powder, Cr Ni3Al溶 It is 3% to 7%.

[0051] The Ni 3 Al-based alloy powders were prepared by vacuum induction melting atomization (VIGA).

[0052] Another specific embodiment of the present invention discloses a copper alloy surface cladding layer, wherein the cladding layer adopts the above-mentioned Ni 3 It is prepared from Al-based alloy powder.

[0053] Another specific embodiment of the present invention discloses a method for preparing a copper alloy surface cladding layer, comprising the following steps:

[0054] Step 1: pretreating the surface of the copper alloy substrate;

[0055] Step 2: Set the cladding track, which can be unidirectional or reciprocating;

[0056] Step 3: preheating the pretreated copper alloy substrate;

[0057] Step 4: Use coaxial powder feeding method to feed Ni 3 Al-based alloy powder is conveyed to the surface of the preheated copper alloy substrate;

[0058] Step 5: Use laser cladding method to 3 The Al-based alloy powder is clad on the surface of the copper alloy substrate to form a cladding layer.

[0059] Specifically, in step 1, the pretreatment includes roughening treatment and de-impurity treatment.

[0060] Preferably, the roughening treatment method is mainly sandblasting, sandpaper polishing, etc.; the impurity removal treatment is to remove oil and dust on the surface.

[0061] Specifically, in step 3, the preheating temperature in the preheating treatment is 150°C to 300°C, for example, 170°C, 190°C, 210°C, 230°C, 250°C, 270°C, or 290°C.

[0062] It should be noted that when the preheating temperature is lower than 150°C, it is difficult to achieve good metallurgical bonding between the cladding layer and the substrate; when the preheating temperature is higher than 300°C, the copper alloy substrate tends to soften and the surface is severely oxidized, and defects are easily formed in the bonding area between the cladding layer and the copper substrate.

[0063] Specifically, in step 4, the Ni 3 The particle size of the Al-based alloy powder is 53 μm to 125 μm, and the coaxial powder feeding rate is 5 g / min to 15 g / min (for example, 7 g / min, 9 g / min, 11 g / min, 13 g / min).

[0064] It should be noted that when the powder particle size is greater than 125μm, unmelted powder particles are likely to appear in the cladding layer; when the powder particle size is less than 53μm, the powder is likely to adhere to the wall of the powder feeding tube during the cladding powder feeding process, and the powder feeding is not smooth. When the powder feeding rate is lower than 5g / min, the matrix dilution rate is high, the cladding layer thickness is small, and it does not meet the application requirements; when the powder feeding rate is higher than 15g / min, unmelted powder particles are likely to appear in the cladding layer, and the crack tendency increases.

[0065] Specifically, in step 5, the laser beam in the laser cladding method is a circular spot or a rectangular spot;

[0066] When the laser beam is a circular spot, the diameter of the circular spot is 2mm to 4mm; when the laser beam is a rectangular spot, the length of the rectangular spot is 4mm to 6mm and the width is 2mm to 5mm;

[0067] It should be noted that when the spot size is too small, the cladding efficiency is low and the difficulty of overlapping multiple cladding passes increases; when the spot size is too large, the cladding layer and the copper substrate are prone to non-fusion.

[0068] The laser beam is directed at an angle of 5° to 20° along the cladding direction to the normal line of the copper substrate surface, for example, 7°, 9°, 11°, 13°, 15°, 17°, or 19°.

[0069] It should be noted that Cu has high laser reflectivity. When the angle between the laser beam and the surface normal of the copper substrate along the cladding direction is less than 5°, the laser is reflected back to the laser optical path, which is easy to damage the optical path system; when the angle between the laser beam and the surface normal of the copper substrate along the cladding direction is greater than 20°, the spot size increases, and the laser power density distribution is uneven, resulting in unstable cladding quality.

[0070] Specifically, in step 5, the cladding process parameters in the laser cladding method are: laser power 5000W~8000W (for example, 5500W, 6000W, 6500W, 7000W, 7500W), scanning speed 0.15m / min~0.45m / min (for example, 0.20m / min, 0.25m / min, 0.30m / min, 0.35m / min, 0.40m / min), and the shielding gas is argon.

[0071] It should be noted that when the laser power is lower than 5000W, the cladding layer and the copper substrate are prone to non-fusion. When the laser power is higher than 8000W, the dilution rate of the copper substrate is high, which reduces the wear resistance of the cladding layer and increases the tendency of cladding cracks.

[0072] When the scanning speed is lower than 0.15m / min, the dilution rate of the copper matrix is ​​high, which reduces the wear resistance of the cladding layer and increases the tendency of cladding cracks. When the scanning speed is higher than 0.45m / min, the problem of non-fusion between the cladding layer and the copper matrix is ​​prone to occur.

[0073] Specifically, the average hardness of the copper alloy surface cladding layer is ≥490HV, the shear strength of the interface is ≥350MPa, and under dry friction conditions (point friction, the grinding material is Si 3 N 4 ), the room temperature wear rate is ≤1.85×10 -5 mm 3 / (N·m), wear rate at 300℃≤2.00×10 -5 mm 3 / (N·m).

[0074] Specifically, the structure of the copper alloy surface cladding layer includes Ni 3 Al phase, γ-Ni phase and Cr 7 C 3 Mutually.

[0075] Another specific embodiment of the present invention discloses a Ni 3 Application of Al-based alloy powder in surface modification of continuous casting mold copper plates in the metallurgical field.

[0076] The technical effects of the present invention are further explained below in conjunction with specific embodiments.

[0077] Example 1

[0078] A copper alloy surface laser cladding Ni 3 Al-based alloy powder, the alloy powder is prepared by vacuum induction melting atomization (VIGA), the Ni 3 The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 6.70%, C: 3.20%, Cr: 36.0%, B: 0.050%, O: 150ppm, N: 25ppm, H: 3ppm, and the balance is Ni.

[0079] Ni 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3 , the mass content of carbides is 35.0%. Ni 3 The atomic ratio of the nickel equivalent to the aluminum equivalent of the Al-based alloy powder is 3.33.

[0080] A method for preparing a copper alloy surface cladding layer in this embodiment includes the following steps:

[0081] Step 1: The surface of the copper alloy substrate is roughened by sandpaper to remove oil and dust on the surface;

[0082] Step 2: Set the cladding track, which is a one-way movement;

[0083] Step 3: preheating the pretreated copper alloy substrate;

[0084] Step 4: Use coaxial powder feeding method to feed Ni 3 Al-based alloy powder is transported to the surface of the preheated copper alloy substrate, wherein Ni 3 The particle size of Al-based alloy powder ranges from 53μm to 125μm, and the coaxial powder feeding rate is 10g / min;

[0085] Step 5: Use laser cladding method to 3 Al-based alloy powder is clad on the surface of the copper alloy substrate. The laser power is 5500W, the scanning speed is 0.30m / min, the laser rectangular spot size is 5mm×2mm, and the laser beam is 10° along the cladding direction with the normal line of the copper substrate surface to form in-situ self-generated carbide-enhanced Ni 3 Al-based alloy cladding layer.

[0086] Using the Ni 3 Three groups of cladding layers were prepared using Al-based alloy powders, the only difference being that in step 3, the pretreated copper alloy substrate was preheated to 150°C, 200°C, and 250°C, respectively.

[0087] The macroscopic morphology of the three groups of single-pass laser cladding layers prepared in this embodiment is as follows: Figure 1 As shown, the cladding layer is well bonded to the substrate.

[0088] Among them, the macroscopic morphology of the cladding layer prepared by preheating the copper alloy to 200 °C and the interface morphology with the substrate are as follows: Figure 2 and Figure 3 As shown. Figure 2 and Figure 3 , the Ni obtained in this embodiment 3 The Al-based alloy cladding layer has no cracks and has good metallurgical bonding with the substrate. The microstructure of the cladding layer includes Ni 3 Al phase, γ-Ni phase and Cr 7 C 3 Phase (such as Figure 4 As shown), the tissue structure is dense, and the in situ self-generated Cr 7 C 3 The carbides are evenly distributed.

[0089] The Ni prepared in this example 3 The average hardness of the Al-based alloy cladding layer is 532HV, and the shear strength of the interface is 395MPa. 3 N 4 ), Ni 3 The wear rate of Al-based alloy cladding layer at room temperature is 1.45×10 -5 mm 3 / (N·m), wear rate at 300℃ is 1.71×10 -5 mm 3 / (N·m).

[0090] The cladding layer prepared in this embodiment is different from the Stellite 6 cobalt-based alloy cladding layer in the prior art (wear rate at room temperature is 3.16×10 -5 mm 3 / (N·m), wear rate at 300℃4.26×10 -5 mm 3 / (N·m)), the wear rates were reduced by 54.12% and 59.86% respectively.

[0091] Example 2

[0092] A copper alloy surface laser cladding Ni 3 Al-based alloy powder, the alloy powder is prepared by vacuum induction melting atomization (VIGA), the Ni 3 The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 6.61%, C: 3.49%, Cr: 37.47%, B: 0.046%, O: 180ppm, N: 27ppm, H: 3ppm, and the balance is Ni.

[0093] Ni 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3 , the mass content of carbides is 37.5%. Ni 3 The atomic ratio of the nickel equivalent to the aluminum equivalent of the Al-based alloy powder is 3.39.

[0094] A method for preparing a copper alloy surface cladding layer in this embodiment includes the following steps:

[0095] Step 1: The surface of the copper alloy substrate is roughened by sandpaper to remove oil and dust on the surface;

[0096] Step 2: Set the cladding track, which is a one-way movement;

[0097] Step 3: preheating the pretreated copper alloy substrate to 200° C.

[0098] Step 4: Use coaxial powder feeding method to feed Ni 3 Al-based alloy powder is transported to the surface of the preheated copper alloy substrate, wherein Ni 3 The particle size of Al-based alloy powder ranges from 53μm to 125μm, and the coaxial powder feeding rate is 10g / min;

[0099] Step 5: Use laser cladding method to 3 Al-based alloy powder is clad on the surface of the copper alloy substrate. The laser power is 5500W, the scanning speed is 0.30m / min, the laser rectangular spot size is 5mm×2mm, and the laser beam is 10° along the cladding direction with the normal line of the copper substrate surface to form in-situ self-generated carbide-enhanced Ni 3Al-based alloy cladding layer.

[0100] The cladding layer prepared in this embodiment has no cracks and has good metallurgical bonding with the substrate. The microstructure of the cladding layer includes Ni 3 Al phase, γ-Ni phase and Cr 7 C 3 Mutually.

[0101] The average hardness of the cladding layer prepared in this embodiment is 558HV, and the shear strength of the interface is 376MPa. 3 N 4 ), Ni 3 The wear rate of Al-based alloy cladding layer at room temperature is 1.60×10 -5 mm 3 / (N·m), wear rate at 300℃ is 1.86×10 -5 mm 3 / (N·m).

[0102] Example 3

[0103] A copper alloy surface laser cladding Ni 3 Al-based alloy powder, the alloy powder is prepared by vacuum induction melting atomization (VIGA), the Ni 3 The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 7.08%, C: 3.03%, Cr: 34.56%, B: 0.055%, O: 152ppm, N: 23ppm, H: 3ppm, and the balance is Ni.

[0104] Ni 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3 , the mass content of carbides is 33%. Ni 3 The atomic ratio of the nickel equivalent to the aluminum equivalent of the Al-based alloy powder is 3.22.

[0105] A method for preparing a copper alloy surface cladding layer in this embodiment includes the following steps:

[0106] Step 1: The surface of the copper alloy substrate is roughened by sandpaper to remove oil and dust on the surface;

[0107] Step 2: Set the cladding track, which is a one-way movement;

[0108] Step 3: preheating the pretreated copper alloy substrate to 200° C.

[0109] Step 4: Use coaxial powder feeding method to feed Ni 3 Al-based alloy powder is transported to the surface of the preheated copper alloy substrate, wherein Ni 3 The particle size of Al-based alloy powder ranges from 53μm to 125μm, and the coaxial powder feeding rate is 10g / min;

[0110] Step 5: Use laser cladding method to 3 Al-based alloy powder is clad on the surface of the copper alloy substrate. The laser power is 5500W, the scanning speed is 0.30m / min, the laser rectangular spot size is 5mm×2mm, and the laser beam is 10° along the cladding direction with the normal line of the copper substrate surface to form in-situ self-generated carbide-enhanced Ni 3 Al-based alloy cladding layer.

[0111] The cladding layer prepared in this embodiment has no cracks and has good metallurgical bonding with the substrate. The microstructure of the cladding layer includes Ni 3 Al phase, γ-Ni phase and Cr 7 C 3 Mutually.

[0112] The Ni prepared in this example 3 The average hardness of the Al-based alloy cladding layer is 497HV, and the shear strength of the interface is 353MPa. 3 N 4 ), Ni 3 The room temperature wear rate of Al-based alloy cladding layer is 1.83×10 -5 mm 3 / (N·m), wear rate at 300℃ is 1.98×10 -5 mm 3 / (N·m).

[0113] Example 4

[0114] A copper alloy surface laser cladding Ni 3 Al-based alloy powder, the alloy powder is prepared by vacuum induction melting atomization (VIGA), the Ni 3 The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 6.70%, C: 3.20%, Cr: 36.0%, B: 0.050%, O: 150ppm, N: 25ppm, H: 3ppm, and the balance is Ni.

[0115] Ni 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3, the mass content of carbides is 35%. Ni 3 The atomic ratio of the nickel equivalent to the aluminum equivalent of the Al-based alloy powder is 3.33.

[0116] A method for preparing a copper alloy surface cladding layer in this embodiment includes the following steps:

[0117] Step 1: The surface of the copper alloy substrate is roughened by sandpaper to remove oil and dust on the surface;

[0118] Step 2: Set the cladding track, which is a one-way movement;

[0119] Step 3: preheating the pretreated copper alloy substrate to 150° C.

[0120] Step 4: Use coaxial powder feeding method to feed Ni 3 Al-based alloy powder is transported to the surface of the preheated copper alloy substrate, wherein Ni 3 The particle size of Al-based alloy powder ranges from 53μm to 125μm, and the coaxial powder feeding rate is 15g / min;

[0121] Step 5: Use laser cladding method to 3 Al-based alloy powder is clad on the surface of the copper alloy substrate. The laser power is 7800W, the scanning speed is 0.15m / min, the laser rectangular spot size is 6mm×5mm, and the laser beam is 20° along the cladding direction with the normal line of the copper substrate surface to form in-situ self-generated carbide-enhanced Ni 3 Al-based alloy cladding layer.

[0122] The cladding layer prepared in this embodiment has no cracks and has good metallurgical bonding with the substrate. The microstructure of the cladding layer includes Ni 3 Al phase, γ-Ni phase and Cr 7 C 3 Mutually.

[0123] The Ni prepared in this example 3 The average hardness of the Al-based alloy cladding layer is 545HV, and the shear strength of the interface is 361MPa. Under dry friction conditions (point friction, the grinding material is Si 3 N 4 ), Ni 3 The room temperature wear rate of the Al-based alloy cladding layer is 1.64×10 -5 mm 3 / (N·m), wear rate at 300℃ is 1.79×10 -5 mm 3 / (N·m).

[0124] Example 5

[0125] A copper alloy surface laser cladding Ni 3 Al-based alloy powder, the alloy powder is prepared by vacuum induction melting atomization (VIGA), the Ni 3 The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 6.70%, C: 3.20%, Cr: 36.0%, B: 0.050%, O: 150ppm, N: 25ppm, H: 3ppm, and the balance is Ni.

[0126] Ni 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3 , the mass content of carbides is 35%. Ni 3 The atomic ratio of the nickel equivalent to the aluminum equivalent of the Al-based alloy powder is 3.33.

[0127] A method for preparing a copper alloy surface cladding layer in this embodiment includes the following steps:

[0128] Step 1: The surface of the copper alloy substrate is roughened by sandpaper to remove oil and dust on the surface;

[0129] Step 2: Set the cladding track, which is a one-way movement;

[0130] Step 3: preheating the pretreated copper alloy substrate to 250° C.

[0131] Step 4: Use coaxial powder feeding method to feed Ni 3 Al-based alloy powder is transported to the surface of the preheated copper alloy substrate, wherein Ni 3 The particle size of Al-based alloy powder ranges from 53μm to 125μm, and the coaxial powder feeding rate is 5g / min;

[0132] Step 5: Use laser cladding method to 3 Al-based alloy powder is clad on the surface of copper alloy substrate. The laser power is 6000W, the scanning speed is 0.45m / min, the laser circular spot diameter is 3mm, and the laser beam is 5° along the cladding direction with the normal line of the copper substrate surface to form in-situ self-generated carbide-enhanced Ni 3 Al-based alloy cladding layer.

[0133] The cladding layer prepared in this embodiment has no cracks and has good metallurgical bonding with the substrate. The microstructure of the cladding layer includes Ni 3 Al phase, γ-Ni phase and Cr 7 C 3 Mutually.

[0134] The Ni prepared in this example 3 The average hardness of the Al-based alloy cladding layer is 514HV, and the shear strength of the interface is 402MPa. 3 N 4 ), Ni 3 The wear rate of Al-based alloy cladding layer at room temperature is 1.75×10 -5 mm 3 / (N·m), wear rate at 300℃ is 1.90×10 -5 mm 3 / (N·m).

[0135] Comparative Example 1

[0136] Ni 3 The Al-based alloy powder has the following chemical compositions by mass percentage: Al: 7.30%, C: 3.21%, Cr: 35.91%, B: 0.049%, O: 145ppm, N: 27ppm, H: 3ppm, and the balance is Ni. 3 The atomic ratio of the nickel equivalent to the aluminum equivalent of the Al-based alloy powder is 3.07.

[0137] The preparation method of the copper alloy surface cladding layer in this embodiment is the same as that in Example 2.

[0138] The interface morphology between the cladding layer and the substrate prepared in this comparative example is as follows: Figure 5 As shown in the figure, it can be seen that there is an obvious unfused area between the cladding layer prepared in this comparative example and the substrate.

[0139] Comparative Example 2

[0140] Ni 3 The chemical composition of the Al-based alloy powder is as follows: Al: 6.51%, C: 3.19%, Cr: 35.86%, B: 0.045%, O: 143ppm, N: 29ppm, H: 3ppm, and the balance is Ni. 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3 , the mass content of carbides is 35.0%. Ni 3 The atomic ratio of the nickel equivalent to the aluminum equivalent of the Al-based alloy powder is 3.51.

[0141] The preparation method of the copper alloy surface cladding layer in this embodiment is the same as that in Example 2.

[0142] The Ni prepared in this comparative example 3The average hardness of the Al-based alloy cladding layer is 447HV, and the shear strength of the interface is 321MPa. 3 N 4 ), Ni 3 The wear rate of Al-based alloy cladding layer at room temperature is 3.08×10 - 5 mm 3 / (N·m), wear rate at 300℃ is 4.30×10 -5 mm 3 / (N·m), which is comparable to the wear rate of Stellite 6 cobalt-based alloy cladding layer.

[0143] Comparative Example 3

[0144] Ni 3 The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 6.70%, C: 3.20%, Cr: 36.0%, B: 0.050%, O: 150ppm, N: 25ppm, H: 3ppm, and the balance is Ni.

[0145] Ni 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3 , the mass content of carbides is 35.0%. Ni 3 The atomic ratio of the nickel equivalent to the aluminum equivalent of the Al-based alloy powder is 3.33.

[0146] A method for preparing a copper alloy surface cladding layer in this comparative example comprises the following steps:

[0147] Step 1: The surface of the copper alloy substrate is roughened by sandpaper to remove oil and dust on the surface;

[0148] Step 2: Set the cladding track, which is a one-way movement;

[0149] Step 3: preheating the pretreated copper alloy substrate to 100° C.

[0150] Step 4: Use coaxial powder feeding method to feed Ni 3 Al-based alloy powder is transported to the surface of the preheated copper alloy substrate, wherein Ni 3 The particle size of Al-based alloy powder ranges from 53μm to 125μm, and the coaxial powder feeding rate is 20g / min;

[0151] Step 5: Use laser cladding method to 3Al-based alloy powder was clad on the surface of the copper alloy substrate. The laser power was 7800 W, the scanning speed was 0.12 m / min, the laser rectangular spot size was 6 mm × 6 mm, and the laser beam was 20° to the normal of the copper substrate surface along the cladding direction.

[0152] The Ni prepared in this comparative example 3 There is an obvious unfused area between the Al-based alloy cladding layer and the substrate.

[0153] Comparative Example 4

[0154] Ni 3 The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 6.70%, C: 3.20%, Cr: 36.0%, B: 0.050%, O: 150ppm, N: 25ppm, H: 3ppm, and the balance is Ni.

[0155] Ni 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3 , the mass content of carbides is 35.0%. Ni 3 The atomic ratio of the nickel equivalent to the aluminum equivalent of the Al-based alloy powder is 3.33.

[0156] A method for preparing a copper alloy surface cladding layer in this comparative example comprises the following steps:

[0157] Step 1: The surface of the copper alloy substrate is roughened by sandpaper to remove oil and dust on the surface;

[0158] Step 2: Set the cladding track, which is a one-way movement;

[0159] Step 3: preheating the pretreated copper alloy substrate to 200° C.

[0160] Step 4: Use coaxial powder feeding method to feed Ni 3 Al-based alloy powder is transported to the surface of the preheated copper alloy substrate, wherein Ni 3 The particle size of Al-based alloy powder ranges from 53μm to 125μm, and the coaxial powder feeding rate is 5g / min;

[0161] Step 5: Use laser cladding method to 3 Al-based alloy powder is clad on the surface of copper alloy substrate. The laser power is 4000W, the scanning speed is 0.60m / min, the laser circular spot diameter is 3mm, and the laser beam is 5° with the normal line of the copper substrate surface along the cladding direction to form in-situ self-generated carbide-enhanced Ni 3Al-based alloy cladding layer. 3 There is an obvious unfused area between the Al-based alloy cladding layer and the substrate.

[0162] Comparative Example 5

[0163] Ni 3 The chemical composition of the Al-based alloy powder is, by mass percentage, Al: 6.70%, C: 3.20%, Cr: 36.0%, B: 0.050%, O: 150ppm, N: 25ppm, H: 3ppm, and the balance is Ni.

[0164] Ni 3 The microstructure of Al-based alloy powder includes Ni 3 Al phase, γ-Ni phase and carbide. The carbide structure mainly includes Cr 7 C 3 , the mass content of carbides is 35.0%. Ni 3 The atomic ratio of the nickel equivalent to the aluminum equivalent of the Al-based alloy powder is 3.33.

[0165] A method for preparing a copper alloy surface cladding layer in this comparative example comprises the following steps:

[0166] Step 1: The surface of the copper alloy substrate is roughened by sandpaper to remove oil and dust on the surface;

[0167] Step 2: Set the cladding track, which is a one-way movement;

[0168] Step 3: preheating the pretreated copper alloy substrate to 200° C.

[0169] Step 4: Use coaxial powder feeding method to feed Ni 3 Al-based alloy powder is transported to the surface of the preheated copper alloy substrate, wherein Ni 3 The particle size of Al-based alloy powder ranges from 53μm to 125μm, and the coaxial powder feeding rate is 5g / min;

[0170] Step 5: Use laser cladding method to 3 Al-based alloy powder is clad on the surface of copper alloy substrate. The laser power is 1800W, the scanning speed is 0.75m / min, the laser circular spot diameter is 3mm, and the laser beam is 10° along the cladding direction with the normal line of the copper substrate surface to form in-situ self-generated carbide-enhanced Ni 3 Al-based alloy cladding layer.

[0171] The Ni prepared in this comparative example 3 The average hardness of the Al-based alloy cladding layer is 417HV, and the shear strength of the interface is 336MPa.3 N 4 ), Ni 3 The wear rate of Al-based alloy cladding layer at room temperature is 3.42×10 -5 mm 3 / (N·m), wear rate at 300℃ is 4.68×10 -5 mm 3 / (N·m).

[0172] Compared with Example 1, the cladding layer prepared in this comparative example has lower average hardness and interface shear strength, and higher wear rate.

[0173] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A Ni3Al-based alloy powder for laser cladding on copper alloy surface, characterized in that: The chemical composition of the Ni3Al-based alloy powder is, by mass percentage, Al: 6.6%-7.1%, C: 3.0%-3.5%, Cr: 34.5%-37.5%, B: 0.041%-0.06%, O≤200ppm, N≤30ppm, H≤5ppm, and the balance is Ni.

2. The Ni3Al-based alloy powder for laser cladding on copper alloy surface according to claim 1, characterized in that: The microstructure of the Ni3Al-based alloy powder includes a Ni3Al phase, a γ-Ni phase and carbides.

3. The Ni3Al-based alloy powder for laser cladding on copper alloy surface according to claim 1 or 2, characterized in that: The atomic ratio of nickel equivalent to aluminum equivalent of the Ni3Al-based alloy powder is 3.2 to 3.

45.

4. A copper alloy surface cladding layer, characterized in that: The cladding layer is prepared by using the Ni3Al-based alloy powder described in any one of claims 1-3.

5. A method for preparing a copper alloy surface cladding layer according to claim 4, characterized in that: The following steps are involved: Step 1: pretreating the surface of the copper alloy substrate; Step 2: Set the cladding track, which can be unidirectional or reciprocating; Step 3: preheating the pretreated copper alloy substrate; Step 4: using a coaxial powder feeding method to convey the Ni3Al-based alloy powder to the surface of the preheated copper alloy substrate; Step 5: Use a laser cladding method to clad the Ni3Al-based alloy powder on the surface of the copper alloy substrate to form a cladding layer.

6. The preparation method according to claim 5, characterized in that: In step 1, the pretreatment includes roughening treatment and de-impurity treatment.

7. The preparation method according to claim 5, characterized in that: In step 3, the preheating temperature in the preheating treatment is 150°C to 300°C.

8. The preparation method according to claim 5, characterized in that: In step 4, the particle size of the Ni3Al-based alloy powder is 53 μm to 125 μm, and the coaxial powder feeding rate is 5 g / min to 15 g / min.

9. The preparation method according to claim 5, characterized in that: In step 5, the cladding process parameters in the laser cladding method are: laser power 5000W to 8000W, scanning speed 0.15m / min to 0.45m / min, and shielding gas is argon.

10. Use of the Ni3Al-based alloy powder according to any one of claims 1 to 3 in surface modification of continuous casting crystallizer copper plates in the metallurgical field.

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