Cu-cr-nb-re alloy

Abstract

A Cu-Cr-Nb-RE alloy, wherein the Cu-Cr-Nb-RE alloy simultaneously contains Cu, Cr, Nb and RE; the difference between the tensile strength of a formed part in a Z-axis direction and that in a direction perpendicular to the Z-axis is less than 7.5%; and the Cu-Cr-Nb-RE alloy is prepared by means of additive manufacturing. The Cu-Cr-Nb-RE alloys with different texture intensities, different grain sizes, good mechanical properties and extremely low anisotropy can be prepared by means of the cooperation between laser power and scan rate parameters within the range of the designed composition of the alloy.

Description

A Cu-Cr-Nb-RE alloy Technical Field

[0001] The invention relates to a Cu-Cr-Nb-RE alloy, and belongs to the field of non-ferrous metals and additive manufacturing. Background Art

[0002] Cu-Cr-Nb alloys have been successfully used in space shuttle main engines due to their excellent high-temperature mechanical properties, good thermal conductivity, low-cycle fatigue resistance, thermal expansion, and brazing properties, making them one of the most promising heat-resistant copper alloys. Additive manufacturing (also known as printing or 3D printing) offers a new approach to the preparation of Cu-Cr-Nb alloys. The extremely rapid cooling rate during the forming process increases the supersaturated solid solubility of the solute elements, resulting in a small size of the second phase, Cr2Nb. Subsequent heat treatment significantly improves the overall performance of Cu-Cr-Nb alloys. Therefore, additive manufacturing has become an important technology for preparing high-performance Cu-Cr-Nb alloys. Technical issues

[0003] When Cu-Cr-Nb alloy is prepared by laser powder bed fusion, when the Cr and Nb content in the Cu-Cr-Nb alloy is low, the Cu-Cr-Nb alloy formed part samples prepared by LPBF have significant anisotropy and high texture strength. Adjusting the laser process parameters in the LPBF process has no significant effect on the texture strength of the alloy, and cannot improve the anisotropy problem of the alloy. Existing research results show that Ren Yake [Ren Yake. Study on the microstructure and properties of Cu-Cr-Nb alloy prepared by selective laser melting [D]. Central South University, 2021.] used different process parameters to prepare Cu-Cr-Nb alloy samples with a relative density greater than 99% (Cr: 1.58wt.%, Nb: 1.08wt.%), which showed a strong {110} texture parallel to the construction direction. The microhardness of the additively manufactured parts was 128HV, the yield strength in the Z-axis direction was 248 MPa, the tensile strength was 343 MPa, the yield strength perpendicular to the Z-axis direction was 292 MPa, the tensile strength was 382 MPa, and the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis was 0. The Cr content is 11.37%, exhibiting significant anisotropy, with yield ratios of 0.76 and 0.72 in the two directions, respectively. Ai Yongkang [Ai Yongkang. Microstructure and Properties of Cu-Cr-Nb-Ce Alloy Prepared by Selective Laser Melting [D]. Central South University, 2022.] The {110} texture strength of the additively manufactured Cu-Cr-Nb-Ce alloy (Cr: 1.74 wt.%, Nb: 0.97 wt.%, Ce trace) weakened somewhat after the addition of rare earth element Ce, but the overall texture remained high. The microhardness of the formed part was 126 HV, the yield strength was 286 MPa, the tensile strength was 403 MPa, and the yield ratio was greater than 0.71. Therefore, the microstructure of Cu-Cr-Nb alloys prepared by additive manufacturing is difficult to control, especially the {110} texture strength parallel to the build direction, which is difficult to reduce. This results in strong anisotropy and poor mechanical properties in the formed part. Technical Solutions

[0004] Based on this, the present invention proposes for the first time that the anisotropy of Cu-Cr-Nb alloys can be reduced by increasing the Cr and Nb contents while adding appropriate amounts of rare earth elements. The present invention also proposes for the first time that, within the designed alloy composition range, by synergizing laser power and scan rate parameters, Cu-Cr-Nb-RE alloys with varying texture strengths, varying grain sizes, excellent mechanical properties, and extremely low anisotropy can be successfully prepared.

[0005] Under the synergistic effect of composition and process parameters, the present invention can also regulate the microstructure of the additively manufactured Cu-Cr-Nb alloy, which provides the necessary conditions for obtaining high-performance Cu-Cr-Nb alloy.

[0006] The present invention provides a Cu-Cr-Nb-RE alloy, wherein the Cu-Cr-Nb-RE alloy contains Cu, Cr, Nb, and RE at the same time, and the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis of the formed part is <7.5%, the Cu-Cr-Nb-RE alloy is prepared by additive manufacturing.

[0007] The Z-axis direction of the molded part is the construction direction of additive manufacturing.

[0008] The present invention discloses a Cu-Cr-Nb-RE alloy. In additively manufactured parts, the {110} texture strength (MUD) parallel to the build direction is less than 8, and the {110} texture accounts for less than 76%. After optimization, the {110} texture accounts for less than 40%.

[0009] The present invention provides a Cu-Cr-Nb-RE alloy. The Cu-Cr-Nb-RE alloy is a printed product obtained by additive manufacturing using Cu-Cr-Nb-RE alloy powder as a raw material. The Cu-Cr-Nb-RE alloy powder comprises the following components by mass percentage:

[0010] Cr: 3.0-4.0%; Nb: 2.5-4.0%;

[0011] Rare earth RE: 0.1-0.5%; the balance is Cu;

[0012] The RE is one of Y, La, and Ce, preferably Y.

[0013] Preferably, the present invention provides a Cu-Cr-Nb-RE alloy, wherein the Cu-Cr-Nb-RE alloy powder is composed of the following components by mass percentage: Cr: 3.30%; Nb: 3.87%; Y: 0.20%; and the balance is Cu.

[0014] As a preferred embodiment of the present invention, a Cu-Cr-Nb-RE alloy has a difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis direction of the printed part. <3.5%, with low anisotropy.

[0015] In the present invention, is the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis of the formed part. The calculation formula is:

[0016]

[0017] in, is the tensile strength of the formed part in the Z-axis direction, It is the tensile strength of the formed part perpendicular to the Z-axis.

[0018] In the present invention, the definition For low anisotropy, For lower anisotropy, For higher anisotropy, It is highly anisotropic.

[0019] In the present invention, the Cu-Cr-Nb-RE alloy powder is prepared by gas atomization, and the gas should be argon, helium, or a mixed gas of argon and helium, wherein the oxygen content is less than 0.01 wt.%.

[0020] Preferably, the particle size of the Cu-Cr-Nb-RE alloy powder used in the present invention is controlled in the range of 10-74 μm, more preferably 10-53 μm.

[0021] The additive manufacturing technology used in the present invention is selected from one of laser powder bed melting, electron beam melting or coaxial powder feeding laser forming technology, preferably laser powder bed melting.

[0022] The present invention uses the laser line energy density as a reference parameter and adjusts the laser power and scan rate , so that the laser line energy density Between 0.23-0.70 J / mm, when the laser line energy density is less than 0.23 J / mm or greater than 0.70 J / mm, the formed parts will produce unfused defects and keyhole defects, respectively, resulting in a significant decrease in the relative density of the alloy.

[0023] Preferably, the present invention provides a Cu-Cr-Nb-RE alloy. During additive manufacturing, the powder thickness of each layer is controlled to be 30-45 μm, the scanning spacing is controlled to be 70-90 μm, the laser spot diameter is controlled to be 110-140 μm, the laser scanning strategy is set to intra-layer strip reciprocating scanning, and the layer is rotated 67°. A serpentine scanning strategy is adopted during additive manufacturing. During additive manufacturing, the laser power is controlled to be 250-350 W, and the scanning speed range is 500-1100 mm / s.

[0024] The present invention discloses a Cu-Cr-Nb-RE alloy, wherein the microhardness of the additively manufactured part is greater than 200 HV, the yield strength in the Z-axis direction is 417-443 MPa, the tensile strength is 625-681 MPa, the yield strength in the direction perpendicular to the Z-axis is 441-447 MPa, the tensile strength is 631-702 MPa, and the difference between the tensile strength in the Z-axis direction and the direction perpendicular to the Z-axis is Not exceeding 7.5%.

[0025] Preferably, in a Cu-Cr-Nb-RE alloy of the present invention, when additively manufactured, the laser line energy density is used as a reference parameter, and the laser line energy density is within the range of 0.23-0.375 J / mm, and the average grain size of the obtained formed sample is less than 600 μm. 2 , the {110} texture accounts for less than 40%, with a large proportion of randomly oriented grains, and the tensile strength difference between the Z-axis direction and the direction perpendicular to the Z-axis of the printed part No more than 5%, and the degree of anisotropy is low. In practical applications, the laser power can be selected to be greater than or equal to 250W or less than 300W, and the scanning speed can be greater than or equal to 800mm / s or less than or equal to 1100mm / s. Of course, other combinations of laser power and scanning speed that can achieve this laser energy density are also applicable.

[0026] Preferably, in a Cu-Cr-Nb-Y alloy of the present invention, when additively manufactured, the laser line energy density is used as a reference parameter, and the laser line energy density is within the range of 0.23-0.375 J / mm, and the average grain size of the obtained formed sample is greater than 600 μm. 2 , {110} texture accounts for 60-76%, and the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis of the printed part The anisotropy does not exceed 7.5%, and the degree of anisotropy remains low. In practical applications, a laser power greater than or equal to 300W or less than or equal to 350W and a scanning speed greater than or equal to 500mm / s or less than or equal to 800mm / s can be selected. Of course, other combinations of laser power and scanning speed that can achieve this laser energy density are also applicable.

[0027] In the present invention, the laser line energy density , expressed by the following formula:

[0028]

[0029] in, is the laser power, is the laser scanning speed.

[0030] As a further preferred embodiment, the present invention provides a Cu-Cr-Nb-RE alloy, wherein the printed part is subjected to direct aging heat treatment at a heat treatment temperature of 400-550°C and a heat treatment time of 30-180 minutes to obtain a heat-treated Cu-Cr-Nb-RE alloy. Smaller than printed Specifically, the heat-treated Cu-Cr-Nb-RE alloy has a {110} texture ratio of less than 60% and an average size of less than 1000 μm. 2 , microhardness greater than 260HV, yield strength greater than 700MPa, tensile strength greater than 870MPa, the difference in tensile strength between the Z axis direction and the direction perpendicular to the Z axis of the heat-treated formed part When the content is less than 2.5%, the mechanical properties of the obtained alloy are greatly improved and the anisotropy is further reduced. Beneficial effects

[0031] The present invention proposes for the first time to increase the content of Cr and Nb elements in Cu-Cr-Nb alloy and add an appropriate amount of rare earth elements to directly obtain low-anisotropy additively manufactured Cu-Cr-Nb alloy.

[0032] 1. The present invention broadens the additive manufacturing process parameter range by increasing the content of Cr and Nb alloying elements and microalloying with an appropriate amount of rare earth. A high relative density, low anisotropy Cu-Cr-Nb-RE alloy can be printed within a wider range of process parameters.

[0033] 2. The present invention can obtain alloys with different grain sizes and texture strengths through the coordinated regulation of alloy components and laser process parameters, thereby achieving continuous control of the texture strength and grain size of the alloy.

[0034] 3. The printed Cu-Cr-Nb-RE alloy prepared by the present invention has excellent mechanical properties. The microhardness of the printed parts is greater than 200HV, the yield strength is greater than 440MPa, the tensile strength is greater than 630MPa, and the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis is greater than 100%. Less than 7.5%.

[0035] 4. The Cu-Cr-Nb-RE obtained by the present invention can be directly aging treated, and the mechanical properties of the heat-treated samples are further improved; and compared with the printed state, the heat-treated products are Smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is a grain pole figure and an inverse pole figure of the products obtained in Examples 1-6;

[0037] FIG2 is a statistical diagram of the mechanical properties of the products obtained in Examples 1-6;

[0038] FIG3 shows the grain pole figures and inverse pole figures of the products obtained in Comparative Examples 1-4.

[0039] In Figure 1, (a) is a characterization diagram of the product obtained in Example 1, (b) is a characterization diagram of the product obtained in Example 2, (c) is a characterization diagram of the product obtained in Example 3, (d) is a characterization diagram of the product obtained in Example 4, (e) is a characterization diagram of the product obtained in Example 5, and (f) is a characterization diagram of the product obtained in Example 6. Figure 1 shows the proportion of {110} texture, its texture strength, and average grain size in the alloys obtained in each example.

[0040] It can be seen from FIG. 2 that the performance of the products obtained in Examples 1-6 of the present invention is excellent, and the anisotropy problem of the products is well solved.

[0041] In Figure 3, (a) is a characterization diagram of the product obtained in Comparative Example 1, (b) is a characterization diagram of the product obtained in Comparative Example 3, (c) is a characterization diagram of the product obtained in Comparative Example 3, and (d) is a characterization diagram of the product obtained in Comparative Example 4. Figure 3 shows the proportion of {110} texture, its texture strength, and average grain size in the alloys obtained in each comparative example. Modes for Carrying Out the Invention

[0042] Example 1

[0043] Cu-Cr-Nb-Y alloy powder was prepared by argon atomization. The specific composition was as follows (wt.%): Cr: 3.30%; Nb: 3.87%; Y: 0.20%; the balance was Cu. After vibration screening, the alloy powder particle size for laser powder bed fusion forming was 10-53 μm.

[0044] First, the Cu-Cr-Nb-Y alloy powder was dried in a vacuum drying oven at 100°C for 8 h. The dried powder was then loaded into a powder supply cylinder for spreading. The printing substrate was preheated to 100°C, and a mixed gas of 3% nitrogen and 97% argon was introduced into the working chamber until the oxygen content was less than 0.1%.

[0045] Then set the printing parameters as follows: laser power: 250 W, scanning speed: 800 mm / s, and the corresponding laser line energy density E l The laser beam was placed at a rate of 0.31 J / mm, with an overlap spacing of 80 μm, a powder layer thickness of 35 μm, a laser spot diameter of 120 μm, and a laser scanning strategy of reciprocating stripe scanning within the layer, rotating 67° layer by layer, using a serpentine scanning strategy. Printing was performed under these parameters to obtain the as-printed Cu-Cr-Nb-Y alloy.

[0046] The orientation and grain statistics of the printed Cu-Cr-Nb-Y alloy are shown in Figure 1(a). The results in Figure 1(a) show that the {110} texture of the alloy accounts for 17.2%, the maximum texture intensity MUD=2.40, and the average grain size is 368.1μm. 2 The mechanical properties of the printed Cu-Cr-Nb-Y alloy are shown in Figure 2. The results show that the microhardness of the formed part is 211HV, the yield strength in the Z-axis direction is 437MPa, the tensile strength is 625MPa, the yield strength perpendicular to the Z-axis direction is 441MPa, the tensile strength is 631MPa, and the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis is D. t The obtained alloy has low anisotropy.

[0047] Example 2

[0048] Other conditions are the same as those in Example 1, except that:

[0049] Printing parameters are: laser power: 350 W, scanning speed: 1100 mm / s, corresponding to laser line energy density E lThe laser beam was placed at a rate of 0.32 J / mm, with an overlap spacing of 80 μm, a powder layer thickness of 35 μm, a laser spot diameter of 120 μm, and a laser scanning strategy of reciprocating stripe scanning within the layer, rotating 67° layer by layer, using a serpentine scanning strategy. Printing was performed under these parameters to obtain the as-printed Cu-Cr-Nb-Y alloy.

[0050] The orientation and grain statistics of the printed Cu-Cr-Nb-Y alloy are shown in Figure 1(b). The results in Figure 1(b) show that the {110} texture of the alloy accounts for 21.2%, the maximum texture strength MUD=3.17, and the average grain size is 662.1μm2. The mechanical properties of the printed Cu-Cr-Nb-Y alloy are shown in Figure 2. The results show that the microhardness of the formed part is 209HV, the yield strength in the Z-axis direction is 443MPa, the tensile strength is 649MPa, the yield strength perpendicular to the Z-axis direction is 447MPa, the tensile strength is 656MPa, and the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis is D. t The alloy has low anisotropy.

[0051] Example 3

[0052] Other conditions are the same as those in Example 1, except that:

[0053] Printing parameters are: Then set the printing parameters as follows: laser power: 300 W, scanning speed: 800 mm / s, laser line energy density E l The laser beam was placed at a rate of 0.38 J / mm, with an overlap spacing of 80 μm, a powder layer thickness of 35 μm, a laser spot diameter of 120 μm, and a laser scanning strategy of reciprocating stripe scanning within the layer, rotating 67° layer by layer, using a serpentine scanning strategy. Printing was performed under these parameters to obtain the as-printed Cu-Cr-Nb-Y alloy.

[0054] The orientation and grain statistics of the printed Cu-Cr-Nb-Y alloy are shown in Figure 1(c). The results in Figure 1(c) show that the {110} texture of the alloy accounts for 38.6%, the maximum texture intensity MUD=5.06, and the average grain size is 509.3μm. 2 The mechanical properties of the printed Cu-Cr-Nb-Y alloy are shown in Figure 2. The results show that the microhardness of the formed part is 208HV, the yield strength in the Z-axis direction is 436MPa, the tensile strength is 667MPa, the yield strength perpendicular to the Z-axis is 442MPa, and the tensile strength is 678MPa. The difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis is D. t The alloy has low anisotropy.

[0055] Example 4

[0056] Other conditions are the same as those in Example 1, except that:

[0057] Printing parameters are: Laser power: 350 W, scanning speed: 800 mm / s, corresponding laser line energy density E l The laser beam was blown at a speed of 0.44 J / mm, with an overlap spacing of 80 μm, a powder layer thickness of 35 μm, a laser spot diameter of 120 μm, and a laser scanning strategy of reciprocating strip scanning within the layer, rotating 67° layer by layer. The serpentine scanning strategy was used to print under the set printing parameters to obtain the printed Cu-Cr-Nb-Y alloy.

[0058] The orientation and grain statistics of the printed Cu-Cr-Nb-Y alloy are shown in Figure 1(d). The results in Figure 1(d) show that the {110} texture of the alloy accounts for 60.5%, the maximum texture intensity MUD=5.92, and the average grain size is 809.8μm. 2 The mechanical properties of the printed Cu-Cr-Nb-Y alloy are shown in Figure 2. The results show that the microhardness of the formed part is 207HV, the yield strength in the Z-axis direction is 438MPa, the tensile strength is 681MPa, the yield strength perpendicular to the Z-axis direction is 446MPa, the tensile strength is 702MPa, and the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis is D. t The alloy has low anisotropy.

[0059] Example 5

[0060] Other conditions are the same as those in Example 1, except that:

[0061] Printing parameters are: Laser power: 350 W, scanning speed: 650 mm / s, corresponding laser line energy density E l The laser beam was placed at a rate of 0.54 J / mm, with an overlap spacing of 80 μm, a powder layer thickness of 35 μm, a laser spot diameter of 120 μm, and a laser scanning strategy of reciprocating stripe scanning within the layer, rotating 67° layer by layer, using a serpentine scanning strategy. Printing was performed under these parameters to obtain the as-printed Cu-Cr-Nb-Y alloy.

[0062] The orientation and grain statistics of the printed Cu-Cr-Nb-Y alloy are shown in Figure 1(e). The results in Figure 1(e) show that the {110} texture of the alloy accounts for 75.3%, the maximum texture intensity MUD=7.93, and the average grain size is 1067.3μm. 2The mechanical properties of the printed Cu-Cr-Nb-Y alloy are shown in Figure 2. The results show that the microhardness of the formed part is 204HV, the yield strength in the Z-axis direction is 417MPa, the tensile strength is 652MPa, the yield strength in the direction perpendicular to the Z-axis is 442MPa, the tensile strength is 698MPa, and the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis is D. t The obtained alloy has low anisotropy.

[0063] Example 6

[0064] The printed Cu-Cr-Nb-Y alloy obtained in Example 4 was subjected to direct aging heat treatment. Specifically, the printed product was kept at 450°C for 1 hour and then air-cooled to room temperature to obtain the peak aging-treated Cu-Cr-Nb-Y alloy. The orientation and grain statistics of the alloy are shown in Figure 1(f). Figure 1(f) shows that the {110} texture accounts for 55.6% of the alloy, the maximum texture intensity MUD = 5.37, and the average grain size is 865.2μm. 2 The mechanical properties of the heat-treated Cu-Cr-Nb-Y alloy are shown in Figure 2. The results show that the microhardness of the formed part is 269HV, the yield strength perpendicular to the Z axis is 712MPa, the tensile strength is 893MPa, the yield strength in the Z axis is 708MPa, the tensile strength is 872MPa, and the difference between the tensile strength in the Z axis and the direction perpendicular to the Z axis is D. t The mechanical properties of the alloy obtained are greatly improved and the anisotropy is further reduced.

[0065] Comparative Example 1

[0066] The data used in Comparative Examples 1-4 of the present invention are from Ren Yake’s master’s thesis [Ren Yake. Microstructure and Properties of Cu-Cr-Nb Alloy Prepared by Selective Laser Melting [D]. Central South University, 2021.]

[0067] In Comparative Example 1, a Cu-Cr-Nb alloy was selected as the alloy matrix, and an argon atomization method was used to prepare a Cu-Cr-Nb alloy powder. The specific composition is as follows (wt.%):

[0068] Cr: 1.58%; Nb: 1.08%; the balance is Cu; the alloy powder particle size obtained by vibration screening for laser powder bed fusion forming is 15-53 μm.

[0069] First, the Cu-Cr-Nb alloy powder was dried in a vacuum drying oven at 80°C for 8 h. The dried powder was then loaded into a powder supply cylinder for spreading. The printing substrate was preheated to 100°C, and a mixed gas of 3% nitrogen and 97% argon was introduced into the working chamber until the oxygen content was less than 0.1%.

[0070] Then set the printing parameters as follows: laser power: 330 W, scanning speed: 500 mm / s, and the corresponding laser line energy density E l The laser beam was placed at a rate of 0.66 J / mm, with an overlap spacing of 80 μm, a powder layer thickness of 35 μm, a laser spot diameter of 120 μm, and a laser scanning strategy of reciprocating stripe scanning within the layer, rotating 67° layer by layer, using a serpentine scanning strategy. Printing was performed under these parameters to obtain the printed Cu-Cr-Nb alloy.

[0071] The orientation and grain statistics of the printed Cu-Cr-Nb alloy are shown in Figure 3(a). The results in Figure 3(a) show that the {110} texture of the alloy accounts for 72.9%, the maximum texture intensity MUD=13.62, and the average grain size is 14196.3μm. 2 The microhardness of the printed part is 110HV, the yield strength perpendicular to the Z-axis is 264MPa, and the tensile strength is 351MPa.

[0072] Comparative Example 2

[0073] Other conditions are the same as those in Comparative Example 1, except that:

[0074] Printing parameters are: laser power: 330 W, scanning speed: 800 mm / s, and the energy density of the laser beam E l The laser beam was placed at a rate of 0.41 J / mm, with an overlap spacing of 80 μm, a powder layer thickness of 35 μm, a laser spot diameter of 120 μm, and a laser scanning strategy of reciprocating stripe scanning within the layer, rotating 67° layer by layer, using a serpentine scanning strategy. Printing was performed under these parameters to obtain the printed Cu-Cr-Nb alloy.

[0075] The orientation and grain statistics of the printed Cu-Cr-Nb-Y alloy are shown in Figure 3(b). The results in Figure 3(b) show that the {110} texture of the alloy accounts for 67.5%, the maximum texture intensity MUD=12.52, and the average grain size is 2674.2μm. 2 The microhardness of the formed part is 128HV, the yield strength in the Z-axis direction is 248MPa, the tensile strength is 343MPa, the yield strength perpendicular to the Z-axis direction is 292MPa, the tensile strength is 382MPa, and the difference between the tensile strength in the Z-axis direction and the tensile strength perpendicular to the Z-axis direction is D t The anisotropy of the printed alloy is 11.37%.

[0076] Comparative Example 3

[0077] Other conditions are the same as those in Comparative Example 1, except that:

[0078] The printing parameters are set as follows: laser power: 330 W, scanning speed: 1100 mm / s, and the corresponding laser line energy density E l The laser was printed at a rate of 0.30 J / mm, with an overlap spacing of 80 μm, a powder layer thickness of 35 μm, a laser spot diameter of 120 μm, and a laser scanning strategy of reciprocating stripe scanning within the layer, rotating 67° layer by layer, using a serpentine scanning strategy. Printing was performed under these parameters to obtain the printed Cu-Cr-Nb alloy.

[0079] The orientation and grain statistics of the printed Cu-Cr-Nb alloy are shown in Figure 3(c). The results in Figure 3(c) show that the {110} texture of the alloy accounts for 78.4%, the maximum texture intensity MUD=15.22, and the average grain size is 1563.9μm. 2 The microhardness of the formed part is 117HV, the yield strength perpendicular to the Z-axis is 274MPa, and the tensile strength is 365MPa.

[0080] Comparative Example 4

[0081] Other conditions are the same as those in Comparative Example 1, except that:

[0082] The composition of the alloy powder is as follows (wt.%):

[0083] Cr: 3.52%; Nb: 2.92%; the balance is Cu;

[0084] Printing parameters are: laser power: 350 W, scanning speed: 800 mm / s, corresponding laser line energy density E l The laser beam was placed at a rate of 0.44 J / mm, with an overlap spacing of 80 μm, a powder layer thickness of 35 μm, a laser spot diameter of 120 μm, and a laser scanning strategy of reciprocating stripe scanning within the layer, rotating 67° layer by layer, using a serpentine scanning strategy. Printing was performed under these parameters to obtain the printed Cu-Cr-Nb alloy.

[0085] The orientation and grain statistics of the printed Cu-Cr-Nb alloy are shown in Figure 3(d). The results in Figure 3(d) show that the {110} texture of the alloy accounts for 72.8%, the maximum texture intensity MUD=9.21, and the average grain size is 557.5μm. 2 The microhardness of the formed part is 156HV, the yield strength in the Z-axis direction is 355MPa, the tensile strength is 482MPa, the yield strength perpendicular to the Z-axis direction is 382MPa, the tensile strength is 543MPa, and the difference between the tensile strength in the Z-axis direction and the tensile strength perpendicular to the Z-axis direction is D t It is 12.66%, which shows that the obtained alloy has high anisotropy.

Claims

1. A Cu-Cr-Nb-RE alloy, characterized in that: The Cu-Cr-Nb-RE alloy contains Cu, Cr, Nb, and RE at the same time, and the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis of the formed part is less than 7.5%, and the Cu-Cr-Nb-RE alloy is prepared by additive manufacturing.

2. A Cu-Cr-Nb-RE alloy according to claim 1, characterized in that: The formed part prepared by additive manufacturing has the {110} texture strength MUD in the Z-axis direction less than 8 and the {110} texture proportion less than 76%. After optimization, the {110} texture proportion is less than 40%.

3. A Cu-Cr-Nb-RE alloy according to claim 1, characterized in that: The Cu-Cr-Nb-RE alloy is a as-printed product obtained by additive manufacturing using Cu-Cr-Nb-RE alloy powder. The Cu-Cr-Nb-RE alloy powder, by mass percentage, comprises the following components: Cr: 3.0 - 4.0%; Nb: 2.5 - 4.0%; Rare earth RE: 0.1 - 0.5%; the balance is Cu; The RE is at least one of Y, La, and Ce, preferably Y.

4. A Cu-Cr-Nb-RE alloy according to claim 1, characterized in that: The particle size range of the used Cu-Cr-Nb-RE alloy powder is controlled to be 10 - 74 μm, more preferably 10 - 53 μm.

5. A Cu-Cr-Nb-RE alloy according to claim 1, characterized in that: The used additive manufacturing technology is selected from one of laser powder bed fusion, electron beam melting or coaxial powder feeding laser forming technology, preferably laser powder bed fusion.

6. A Cu-Cr-Nb-RE alloy according to claim 1, characterized in that: During additive manufacturing, the powder thickness of each layer is controlled to be 30 - 45 μm, the scanning spacing is controlled to be 70 - 90 μm, the laser spot diameter is controlled to be 110 - 140 μm, the laser scanning strategy is set as in-layer strip reciprocating scanning, rotating 67° layer by layer, and adopting a serpentine scanning strategy; during additive manufacturing, the laser power is controlled to be 250 - 350 W, and the scanning speed range is 500 - 1100 mm / s.

7. A Cu-Cr-Nb-RE alloy according to claim 1, characterized in that: The yield strength of the printed formed part in the Z-axis direction is greater than or equal to 417 MPa, the tensile strength is greater than or equal to 625 MPa, the yield strength perpendicular to the Z-axis direction is greater than or equal to 441 MPa, the tensile strength is greater than or equal to 631 MPa, and the difference in tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis of the formed part does not exceed 7.5%.

8. A Cu-Cr-Nb-RE alloy according to claim 6, wherein: During additive manufacturing, the laser line energy density is used as a reference parameter, and the laser line energy density is within the range of 0.23 - 0.375 J / mm. The average grain size of the obtained formed part sample is less than 600 μm 2 , the proportion of the {110} texture is less than 40%, and the difference in the tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis of the formed part not exceeding 5%; During additive manufacturing, the laser line energy density is used as a reference parameter, and the laser line energy density is within the range of 0.376 - 0.70 J / mm. The average grain size of the obtained formed part sample is greater than 600 μm 2 , the proportion of the {110} texture is 60 - 76%, and the difference in the tensile strength between the Z-axis direction and the direction perpendicular to the Z-axis of the formed part not exceeding 7.5%, and the degree of anisotropy remains at a low level.

9. A Cu-Cr-Nb-RE alloy according to claim 1, characterized in that: The printed formed part is subjected to direct aging heat treatment. The heat treatment temperature used is 400 - 550 °C, and the heat treatment time is 30 - 180 min to obtain the heat-treated Cu-Cr-Nb-RE alloy; that in the heat-treated state is less than that in the printed state .

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