METHOD FOR PREPARING NANO-PHASE REINFORCED NICKEL-BASED HIGH-TEMPERATURE ALLOY USING MICRON CERAMIC PARTICLES

Abstract

A method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles is provided. In the method, a nickel-based superalloy is used as a matrix, and one or more of TiC, TiB.sub.2, WC and Al.sub.2O.sub.3 are used as a strengthening phase. A ceramic particle raw material used as the strengthening phase has a particle size of 1-5 m and is added in an amount of 1-5 wt. %. A nickel-based superalloy composite powder having homogeneously distributed nano-scale ceramic is prepared by mechanical milling. A nano-scale ceramic phase strengthened nickel-based superalloy is prepared by 3D printing technology, which has a homogeneously distributed nano-scale ceramic phase and excellent mechanical properties.

Claims

1. A method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles, comprising: (1) using micron-scale ceramic particles as a first raw material, and using a nickel-based superalloy powder as a second raw material; wet milling and then dry milling the first raw material and part of the second raw material to obtain a composite powder with homogeneous distribution of nano-scale ceramic particles; (2) mixing the composite powder and the remaining second raw material uniformly to obtain a mixed powder; and (3) 3D printing the mixed powder to obtain a 3D printed product, wherein a weight ratio of the first raw material to the second raw material is: (1-5):(99-95).

2. The method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to claim 1, wherein a particle size of the nickel-based superalloy powder is 15-53 m or 53-106 m; the micron-scale ceramic particles are selected from at least one of TiC, TiB.sub.2, WC and Al.sub.2O.sub.3; a particle size of the micron-scale ceramic particles is 1-5 m; and the 3D printing is selected from one of selective laser melting (SLM), electron beam melting (EBM) and laser engineered net shaping (LENS).

3. The method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to claim 1, wherein the steps further comprise: in step (1) the weight ratio of the first raw material to the second raw material is (1-5):(99-95); in step (2) putting the composite powder prepared in the step (1) and the remaining second raw material into a V-type mixer for uniform mixing to obtain the mixed powder, wherein an inert atmosphere is used for protection during mixing; and in step (3) building a 3D CAD model on a computer according to a part shape; slicing and layering the model using software and then importing it into an additive manufacturing system; then performing repeated laying, scanning, and melting of the uniformly mixed powder prepared in the step (2) layer by layer according to a determined scanning route through a digital control system by using a focused high-energy laser beam, and solidifying the melt, until a 3D part of the 3D printed product is built.

4. The method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to claim 3, wherein in step (1), the ceramic particles and part of the nickel-based superalloy powder are mixed first, and the weight ratio is 1:1-1:5.

5. The method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to claim 3, wherein the wet milling process in step (1) uses ethanol as a milling medium, and wet milling parameters comprise: a ball-to-material ratio of 10:1-5:1, a milling rotation speed of 150-300 rpm, and a milling time of 5-20 h; and the dry milling process is conducted in inert gas, and dry milling parameters comprise: a ball-to-material ratio of 5:1-1:1, a milling rotation speed of 100-200 rpm, and a milling time of 4-10 h.

6. The method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to claim 3, wherein before the 3D printing in step (3), the mixed powder obtained in the step (2) is dried in inert gas at 60-150 C. for 2-12 h.

7. The method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to claim 3, wherein the nickel-based superalloy is a Ren 104 nickel-based superalloy.

8. The method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to claim 3, wherein a substrate used for the 3D printing in step (3) is a stainless steel or a nickel-based superalloy.

9. The method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to claim 3, wherein laser process parameters in step (3) comprise: a laser spot diameter of 70-110 m, a laser power of 150-300 W, a laser scanning speed of 500-1100 mm/s, a laser scanning spacing of 60-120 m, and a powder layer thickness of 30-50 m.

10. The method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to claim 3, wherein the inert gas is helium, argon, or a mixture thereof, with a purity of 99.99 wt. % and an oxygen content of less than 0.0001 wt. %.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG. 1 is a scanning electron microscope (SEM) image of the surface morphology of a nanocomposite powder prepared by wet milling and dry milling of micron-scale ceramic particles and nickel-based superalloy powder in Example 1.

[0031] FIG. 2 is an SEM image of the microstructure of the XY plane of a nano-scale TiC ceramic particle-strengthened Ren104 nickel-based superalloy composite block prepared by laser 3D printing in Example 1.

[0032] FIG. 3 is an SEM image of the microstructure of the XZ plane of a nano-scale TiC ceramic particle-strengthened Ren104 nickel-based superalloy composite block prepared by laser 3D printing in Example 1.

[0033] FIG. 4 is an SEM image of the morphology of a powder prepared by only wet milling in Comparative Example 1.

[0034] FIG. 5 is an SEM image of the morphology of a powder prepared by only dry milling in Comparative Example 2.

DETAILED DESCRIPTION

[0035] The embodiments of the present disclosure will be further described below with reference to the accompanying drawings and specific embodiments.

Example 1

[0036] In a method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to the present disclosure, a Ren104 nickel-based superalloy was used as a matrix, and TiC ceramic particles having an average particle size of 1.5 m were used as strengthening phases, and were added in an amount of 2.0 wt. %.

[0037] The matrix raw material is a spherical Ren104 nickel-based superalloy powder having a particle size of 15-53 m. The Ren104 nickel-based superalloy includes the following components: 20.6% of Co, 13% of Cr, 3.4% of Al, 3.9% of Ti, 3.8% of Mo, 2.1% of W, 2.4% of Ta, 0.9% of Nb, 0.05% of Zr, 0.03% of B, and 0.04% of C, the balance being Ni.

[0038] The preparation steps of the nano-scale ceramic particle-strengthened nickel-based superalloy composite are as follows: [0039] (1) First, the TiC ceramic particles having an average particle size of 1.5 m and part of the Ren104 nickel-based superalloy powder are mixed (at a ratio of 2:3), and then wet milled and dry milled with a high-energy ball milling machine to obtain a composite powder with homogeneous distribution of nano-scale ceramic particles. [0040] (2) The composite powder prepared in the step (1) and the remaining nickel-based superalloy powder are loaded into a V-type mixer for uniform mixing to obtain a mixed powder. An inert atmosphere is used for protection during mixing. [0041] (3) A 3D CAD model is built using a computer according to a part shape. The model is sliced and layered by using software and then is imported into an additive manufacturing system. Repeated laying, scanning, and melting of the uniformly mixed powder prepared in the step (2) are performed layer by layer according to a determined scanning route through a digital control system by using a focused high-energy laser beam, and then the melt is solidified, until a three-dimensional part is built.

[0042] The wet milling process in the step (1) uses ethanol as a milling medium, and wet milling parameters include: a ball-to-material ratio of 7.5:1, a milling rotation speed of 250 rpm, and a milling time of 20 h; and the dry milling process is conducted in inert gas, and dry milling parameters include: a ball-to-material ratio of 3:1, a milling rotation speed of 150 rpm, and a milling time of 8 h.

[0043] Laser process parameters in the step (3) include: a laser spot diameter of 70 m, a laser power of 250 W, a laser scanning speed of 900 mm/s, a laser scanning spacing of 90 m, a powder layer thickness of 40 m, and a heating temperature of the substrate being 200 C.

[0044] The inert gas is argon, with a purity of 99.99 wt. % and an oxygen content of less than 0.0001 wt. %.

[0045] FIG. 1 is an SEM image of the surface morphology of a nanocomposite powder prepared by wet milling and dry milling of micron-scale ceramic particles and nickel-based superalloy powder in Example 1. It can be observed that micron-scale TiC ceramic particles are broken to nanometer scale, to form a composite powder with homogeneous distribution of nano-scale ceramic particles with the matrix Ren 104 alloy powder.

[0046] FIG. 2 is an SEM image of the microstructure of the XY plane of a nano-scale TiC ceramic particle-strengthened nickel-based superalloy composite block prepared by laser 3D printing in Example 1.

[0047] FIG. 3 is an SEM image of the microstructure of the XZ plane of a nano-scale TiC ceramic particle-strengthened nickel-based superalloy composite block prepared by laser 3D printing in Example 1.

[0048] FIG. 2 and FIG. 3 show that the nano-scale TiC ceramic particles prepared by 3D printing are homogeneously distributed in the matrix, and the prepared composite block has fine, homogeneous grains and a compact structure.

[0049] Tests show that the tensile strength of the prepared material sample at room temperature was 1801 MPa; there were 20 microhardness test points, of which the maximum hardness was 613 HV.sub.0.2, the minimum hardness was 569 HV.sub.0.2, and the average hardness was 585 HV.sub.0.2, exhibiting an increase of 62.3% compared with the Ren104 nickel-based superalloy matrix. Friction and wear performance tests show that the friction coefficient was 0.41 and very stable, and the wear amount was 6.210.sup.4 (mm.sup.3/nm) in 30 min.

Example 2

[0050] In a method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to the present disclosure, a Ren104 nickel-based superalloy is used as a matrix, and Al.sub.2O.sub.3 ceramic particles having an average particle size of 2.0 m are used as strengthening phases, and are added in an amount of 3.0 wt. %.

[0051] The matrix raw material is a spherical Ren104 nickel-based superalloy powder having a particle size of 15-53 m. The Ren104 nickel-based superalloy includes the following components: 20.6% of Co, 13% of Cr, 3.4% of Al, 3.9% of Ti, 3.8% of Mo, 2.1% of W, 2.4% of Ta, 0.9% of Nb, 0.05% of Zr, 0.03% of B, and 0.04% of C, the balance being Ni.

[0052] The preparation steps of the nano ceramic particle-strengthened nickel-based superalloy composite are as follows: [0053] (1) First, the TiC ceramic particles having an average particle size of 1.5 m and part of the Ren104 nickel-based superalloy powder are mixed (at a ratio of 1:2), and then wet milled and dry milled with a high-energy ball milling machine to obtain a composite powder with homogeneous distribution of nano-scale ceramic particles. [0054] (2) The composite powder prepared in the step (1) and the remaining nickel-based superalloy powder are loaded into a V-type mixer for uniform mixing to obtain a mixed powder. An inert atmosphere is used for protection during mixing. [0055] (3) A 3D CAD model is built using a computer according to a part shape. The model is sliced and layered by using software and then is imported into an additive manufacturing system. Repeated laying, scanning, and melting of the uniformly mixed powder prepared in the step (2) are performed layer by layer according to a determined scanning route through a digital control system by using a focused high-energy laser beam, and then the melt is solidified, until a three-dimensional part is built.

[0056] The wet milling process in the step (1) uses ethanol as a milling medium, and wet milling parameters include: a ball-to-material ratio of 10:1, a milling rotation speed of 200 rpm, and a milling time of 20 h; and the dry milling process is conducted in inert gas, and dry milling parameters include: a ball-to-material ratio of 5:1, a milling rotation speed of 100 rpm, and a milling time of 10 h.

[0057] Laser process parameters in the step (3) include: a laser spot diameter of 70 m, a laser power of 225 W, a laser scanning speed of 900 mm/s, a laser scanning spacing of 90 m, a powder layer thickness of 30 m, and a heating temperature of the substrate being 170 C.

[0058] The inert gas is argon, with a purity of 99.99 wt. % and an oxygen content of less than 0.0001 wt. %.

[0059] Tests show that the tensile strength of the prepared material sample at room temperature was 1785 MPa; there were 20 microhardness test points, of which the maximum hardness was 621 HV.sub.0.2, the minimum hardness was 577 HV.sub.0.2, and the average hardness was 603 HV.sub.0.2, exhibiting an increase of 68.9% compared with the Ren104 nickel-based superalloy matrix. Friction and wear performance tests show that the friction coefficient was 0.45 and very stable, and the wear amount was 6.910.sup.4 (mm.sup.3/nm) in 30 min.

Example 3

[0060] In a method for preparing a nano-phase strengthened nickel-based superalloy using micron-scale ceramic particles according to the present disclosure, a Ren104 nickel-based superalloy is used as a matrix, and TiC ceramic particles having an average particle size of 1.5 m and WC ceramic particles having an average particle size of 2.5 m are used as strengthening phases, and are added in an amount of 1.5 wt. %.

[0061] The matrix raw material is a spherical Ren104 nickel-based superalloy powder having a particle size of 15-53 m. The Ren104 nickel-based superalloy includes the following components: 20.6% of Co, 13% of Cr, 3.4% of Al, 3.9% of Ti, 3.8% of Mo, 2.1% of W, 2.4% of Ta, 0.9% of Nb, 0.05% of Zr, 0.03% of B, and 0.04% of C, the balance being Ni.

[0062] The preparation steps of the nano-scale ceramic particle-strengthened nickel-based superalloy composite are as follows: [0063] (1) First, the TiC ceramic particles having an average particle size of 1.5 m and part of the Ren104 nickel-based superalloy powder are mixed (at a ratio of 1:2), and then wet milled and dry milled with a high-energy ball milling machine to obtain a composite powder with homogeneous distribution of nano-scale ceramic particles. [0064] (2) The composite powder prepared in the step (1) and the remaining nickel-based superalloy powder are loaded into a V-type mixer for uniform mixing to obtain a mixed powder. An inert atmosphere is used for protection during mixing. [0065] (3) A 3D CAD model is built using a computer according to a part shape. The model is sliced and layered by using software and then is imported into an additive manufacturing system. Repeated laying, scanning, and melting of the uniformly mixed powder prepared in the step (2) are performed layer by layer according to a determined scanning route through a digital control system by using a focused high-energy laser beam, and then the melt is solidified, until a three-dimensional part is built.

[0066] The wet milling process in the step (1) uses ethanol as a milling medium, and wet milling parameters include: a ball-to-material ratio of 10:1, a milling rotation speed of 225 rpm, and a milling time of 20 h; and the dry milling process is conducted in inert gas, and dry milling parameters include: a ball-to-material ratio of 3:1, a milling rotation speed of 150 rpm, and a milling time of 8 h.

[0067] Laser process parameters in the step (3) include: a laser spot diameter of 70 m, a laser power of 250 W, a laser scanning speed of 900 mm/s, a laser scanning spacing of 90 m, a powder layer thickness of 45 and a heating temperature of the substrate being 200 C.

[0068] The inert gas is argon, with a purity of 99.99 wt. % and an oxygen content of less than 0.0001 wt. %.

[0069] Tests show that the tensile strength of the prepared material sample at room temperature was 1782 MPa; there were 20 microhardness test points, of which the maximum hardness was 627 HV.sub.0.2, the minimum hardness was 588 HV.sub.0.2, and the average hardness was 611 HV.sub.0.2, exhibiting an increase of 71.1% compared with the Ren104 nickel-based superalloy matrix. Friction and wear performance tests show that the friction coefficient was 0.55 and very stable, and the wear amount was 7.410.sup.4 (mm.sup.3/nm) in 30 min.

Comparative Example 1

[0070] This comparative example is the same as Example 1 except that in the step (1), only wet milling was conducted.

[0071] FIG. 4 shows the morphology of a composite powder formed by only wet milling. The composite powder formed by only wet milling is likely to agglomerate, which is not conducive to the subsequent mixing with the nickel-based superalloy, resulting in the non-homogeneous distribution of ceramic particles.

[0072] Tests show that the tensile strength of the prepared material sample at room temperature was 1631 MPa; the microhardness at different positions of the prepared composite material differed greatly, and there were 20 microhardness test points, of which the maximum hardness was 615 HV.sub.0.2, the minimum hardness was 363 HV.sub.0.2, and the average hardness was 554 HV.sub.0.2, indicating the non-homogeneous distribution of the ceramic phase. Friction and wear performance tests show that the friction coefficient was 0.61, and the wear amount was 9.510.sup.4 (mm.sup.3/nm) in 30 min.

Comparative Example 2

[0073] This comparative example is the same as Example 1 except that in the step (1), only dry milling was conducted.

[0074] FIG. 5 shows the morphology of a composite powder formed by only dry milling. The ceramic particles cannot be well broken by dry milling alone, and no nanocomposite powder particles were formed.

[0075] Tests show that the tensile strength of the prepared material sample at room temperature was 1609 MPa; the microhardness at different positions of the prepared composite material differed greatly, and there were 20 microhardness test points, of which the maximum hardness was 592 HV.sub.0.2, the minimum hardness was 374 HV.sub.0.2, and the average hardness was 514 HV.sub.0.2, indicating the non-homogeneous distribution of the ceramic phase. Friction and wear performance tests show that the friction coefficient was 0.63, and the wear amount was 9.210.sup.4 (mm.sup.3/nm) in 30 min.

Comparative Example 3

[0076] This comparative example is the same as Example 1 except that in the step (1), dry milling was first conducted followed by wet milling.

[0077] When dry milling was first conducted followed by wet milling, the spherical powder was damaged, resulting in poor powder fluidity, which is not conducive to the preparation of high-quality products by 3D printing.

[0078] Tests show that the tensile strength of the prepared material sample at room temperature was 1702 MPa; there were 20 microhardness test points, of which the maximum hardness was 589 HV.sub.0.2, the minimum hardness was 445 HV.sub.0.2, and the average hardness was 562 HV.sub.0.2. Friction and wear performance tests show that the friction coefficient was 0.53 and very stable, and the wear amount was 7.610.sup.4 (mm.sup.3/nm) in 30 min.

Comparative Example 4

[0079] This comparative example is the same as Example 1 except that in the step (1), wet milling was first conducted followed by dry milling, the wet milling process used ethanol as a milling medium, and wet milling parameters included: a ball-to-material ratio of 4:1, a milling rotation speed of 200 rpm, and a milling time of 10 h; and the dry milling process is conducted in inert gas, and dry milling parameters include: a ball-to-material ratio of 10:1, a milling rotation speed of 200 rpm, and a milling time of 5 h.

[0080] Tests show that the tensile strength of the prepared material sample at room temperature was 1654 MPa; there were 20 microhardness test points, of which the maximum hardness was 620 HV.sub.0.2, the minimum hardness was 447 HV.sub.0.2, and the average hardness was 536 HV.sub.0.2. Friction and wear performance tests show that the friction coefficient was 0.58 and very stable, and the wear amount was 8.310.sup.4 (mm.sup.3/nm) in 30 min.

Comparative Example 5

[0081] A Ren104 nickel-based superalloy was used as a matrix, and TiC ceramic particles having an average particle size of 5 m were used as strengthening phases, and were added in an amount of 2.5 wt. %.

[0082] The matrix raw material is a spherical Ren104 nickel-based superalloy powder having a particle size of 15-53 m. The Ren104 nickel-based superalloy includes the following components: 20.6% of Co, 13% of Cr, 3.4% of Al, 3.9% of Ti, 3.8% of Mo, 2.1% of W, 2.4% of Ta, 0.9% of Nb, 0.05% of Zr, 0.03% of B, and 0.04% of C, the balance being Ni.

[0083] A TiC ceramic phase-strengthened Ren104 nickel-based superalloy was prepared using the method of Example 1 in Chinese patent (CN107116217A). Milling parameters of the method included: a milling speed of 200 r/s, and a milling time of 8 h.

[0084] SLM process parameters included: a laser power of 200 W, a scanning speed of 1000 mm/s, a processing layer thickness of 0.03, and a scanning spacing of 0.04 mm.

[0085] In the composite powder prepared by the method of Chinese patent (CN107116217A), the micron-scale TiC ceramic particles were not formed into nano-scale composite powder, the spherical powder became flaky due to the milling treatment, and the powder fluidity was significantly reduced, which is not conducive to the preparation of high-quality products by 3D printing.

[0086] Tests show that the tensile strength of the prepared material sample at room temperature was 1591 MPa; there were 20 microhardness test points, of which the maximum hardness was 617 HV.sub.0.2, the minimum hardness was 383 HV.sub.0.2, and the average hardness was 475 HV.sub.0.2. Friction and wear performance tests show that the friction coefficient was 0.68, and the wear amount was 10.210.sup.4 (mm.sup.3/nm) in 30 min.