A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method

Abstract

A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method are disclosed. The preparation method is as follows: A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each constituent element; the set mass percentage ratio of each constituent element is 0.2-4.0% Cr, 0.1-1.0% Zr, the content of unavoidable impurity elements is ≤0.1%, and the remainder is Cu; B. Anneal the cast Cu-Cr-Zr alloy; C. After holding the annealed Cu-Cr-Zr alloy at 800-900℃ for 2-4 hours, perform hot extrusion. The process involves several steps: A) The hot-extruded Cu-Cr-Zr alloy is placed in a heat treatment furnace and heated to 900-1040℃ for semi-solid isothermal treatment, held for 0.1-4 hours, and then water-quenched. B) The Cu-Cr-Zr alloy is held at 600-800℃ for 2-4 hours, followed by a second extrusion. The specific operation of the second extrusion is as follows: extrusion temperature 600-800℃, extrusion speed 0.1-5 mm / s, and extrusion ratio 9-60:1. The Cu-Cr-Zr alloy prepared by the above method exhibits excellent yield strength, tensile strength, and elongation.

Description

Technical Field

[0001] This invention relates to a nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method, belonging to the field of copper alloy preparation technology. Background Technology

[0002] Cu-Cr-Zr alloys are widely used in machinery, electrical engineering, and transportation due to their excellent mechanical and electrical properties. As a typical age-hardening alloy, Cu-Cr-Zr alloys exhibit significantly improved strength and conductivity after aging treatment. This is because the dispersed, fine precipitates formed during aging effectively pin dislocations, thus increasing the alloy's strength. Simultaneously, the aging process reduces the concentration of solute atoms in the matrix, minimizing lattice distortion and further enhancing conductivity. However, the low Cr content limits the improvement in alloy strength. Therefore, utilizing novel processes to effectively increase the strength of Cu-Cr-Zr alloys without reducing conductivity, without adding any alloying elements, is of significant engineering importance.

[0003] The particle size and distribution of Cr particles have a significant impact on the mechanical properties of Cu-Cr-Zr alloys. Currently, Cr particles in deformed Cu-Cr-Zr alloys are mostly micrometer-sized, and existing deformation techniques struggle to further refine their size. To obtain particle-reinforced Cu-Cr-Zr alloys with excellent mechanical properties, existing methods increase the eutectic phase volume fraction by increasing the Cr content. However, this leads to a decrease in elongation and a significant increase in cost. In practical applications, Cu-Cr-Zr alloys are required to possess not only good mechanical properties but also excellent electrical conductivity. Therefore, developing high-performance Cu-Cr-Zr alloys with excellent yield strength, tensile strength, elongation, and electrical conductivity is a pressing issue. Summary of the Invention

[0004] The purpose of this invention is to provide a nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method. The Cu-Cr-Zr alloy obtained by this preparation method possesses excellent yield strength, tensile strength, and elongation.

[0005] The technical solution adopted by this invention to achieve its objective is: a nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method, the preparation method steps are as follows:

[0006] A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 0.2-4.0% Cr, 0.1-1.0% Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu;

[0007] B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A;

[0008] C. After holding the annealed Cu-Cr-Zr alloy obtained in step B at 800-900℃ for 2-4 hours, hot extrusion is carried out at an extrusion temperature of 800-900℃, an extrusion speed of 0.1-5mm / s, and an extrusion ratio of 9-30:1.

[0009] D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace, heat it to 900-1040℃ with the furnace for semi-solid isothermal treatment, hold it for 0.1-4h, and then water-quench it.

[0010] E. After holding the Cu-Cr-Zr alloy obtained in step D at 600-800℃ for 2-4 hours, a second extrusion is performed to obtain a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 600-800℃, the extrusion speed is 0.1-5mm / s, and the extrusion ratio is 9-60:1.

[0011] The reaction principle of this invention is:

[0012] The as-cast Cu-Cr-Zr alloy obtained in step A has a eutectic phase morphology of micron-sized lamellar spacing (α-Cu+Cr). After annealing in step B and hot extrusion in step C, the micron-sized eutectic structure is broken into micron-sized Cr particles. Then, step D transforms the micron-sized Cr particles into a nanon-sized eutectic structure (α-Cu+Cr). Finally, after a second extrusion in step E, the nanon-sized eutectic structure is broken into nanon-sized Cr particles, which are dispersed on the α-Cu matrix, thus preparing a high-performance Cu-Cr-Zr alloy with excellent yield strength, tensile strength, and elongation.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] First, the mass percentage content of the constituent elements set in step A ensures that a Cu-Cr-Zr alloy with a eutectic (α-Cu+Cr) interlamellar spacing of nanometers can be obtained through subsequent processing steps B, C, and D. At the same time, the absence of other strengthening alloying elements greatly simplifies the alloy preparation and reduces the alloy preparation cost.

[0015] Second, the annealing treatment in step B gives it better deformability and workability; then the hot extrusion treatment in step C can break the eutectic structure with a lamellar spacing of micrometers into micrometer-sized Cr particles.

[0016] 3. Step D: The particle-reinforced Cu-Cr-Zr alloy with micron-sized Cr particles obtained in step C is subjected to semi-solid treatment. By controlling the semi-solid treatment temperature and time as well as the water quenching temperature after semi-solid treatment, a Cu-Cr-Zr alloy with nanometer-sized eutectic (α-Cu+Cr) interlamellar spacing is obtained in a short time.

[0017] IV. Step E: After obtaining a Cu-Cr-Zr alloy with a eutectic (α-Cu+Cr) interlaminar spacing of nanometers, a secondary extrusion method is selected to break the nano-eutectic phase into nano-scale Cr particles, which are dispersed on the α-Cu matrix, thus obtaining a particle-reinforced Cu-Cr-Zr alloy with nano-scale Cr particles.

[0018] In summary, this invention, based on Cu-Cr-Zr alloys prepared by traditional casting, combines primary extrusion, semi-solid treatment, and secondary extrusion processes to achieve the transformation of the second phase in the alloy from micron-scale lamellar to micron-scale particles, then to nano-scale lamellar, and finally to nano-scale particles. This results in a particle-reinforced Cu-Cr-Zr alloy with nano-scale Cr particles, significantly improving the comprehensive mechanical properties of the Cu-Cr-Zr alloy and greatly expanding its industrial application range.

[0019] Furthermore, in step A of the preparation method of the present invention, the mass percentage content of each constituent element in the preparation of the as-cast Cu-Cr-Zr alloy is set as follows: 0.2-3.2% Cr, 0.1-0.3% Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu.

[0020] Experiments have verified that the mass percentage of the above elements can prepare stable Cu-Cr-Zr alloys with a eutectic (α-Cu+Cr) interlaminar spacing of less than 100 nm. At the same time, the absence of other strengthening alloying elements greatly simplifies the preparation of the alloy and reduces the preparation cost.

[0021] Furthermore, the specific operation of step A in the preparation method of the present invention for preparing the as-cast Cu-Cr-Zr alloy is as follows: according to the set mass percentage ratio of each component element, pure Cu is placed in a crucible and heated to 600-700℃, and high-purity argon gas is introduced. After the pure Cu is completely melted, it is heated to 1250-1300℃ and Cr sheets and Cu-Zr master alloy are added respectively. After stirring for 2-5 minutes, the slag is removed, and it is allowed to stand for 10-20 minutes. When the temperature drops to 1180-1230℃, it is poured to obtain the as-cast Cu-Cr-Zr alloy.

[0022] Furthermore, in the preparation method of the present invention, the annealing temperature of step B, annealing treatment, is 860-940℃, and the annealing time is 10-24h.

[0023] Furthermore, in step C of the preparation method of the present invention, the extrusion ratio for hot extrusion of the Cu-Cr-Zr alloy obtained in step B after annealing is 9-15:1.

[0024] Experiments have verified that the above extrusion ratio can make the thickness of the semi-solid Cu-Cr-Zr alloy layers more uniform, which is beneficial to the preparation of Cu-Cr-Zr alloys with stable nanoscale layer thickness. This is conducive to the preparation of particle-reinforced Cu-Cr-Zr alloys with nanoscale Cr particles that have excellent performance in all aspects.

[0025] Furthermore, in step D of the preparation method of the present invention, the Cu-Cr-Zr alloy obtained in step C after hot extrusion is placed in a heat treatment furnace and heated to 980-1030℃ for semi-solid isothermal treatment, held for 0.1-1h, and then water-cooled and quenched.

[0026] Experiments have verified that the above temperature range and holding time are more conducive to the preparation of Cu-Cr-Zr alloys with stable nanoscale interlamellar spacing, which in turn is beneficial to the preparation of particle-reinforced Cu-Cr-Zr alloys with nanoscale Cr particles that have excellent performance in all aspects.

[0027] Furthermore, in step D of the preparation method of the present invention, the quenching medium for water-cooled quenching is water at 20-80°C.

[0028] Experiments have verified that quenching with water within the above temperature range results in a more uniform layer thickness in the semi-solid Cu-Cr-Zr alloy, which is beneficial for preparing Cu-Cr-Zr alloys with stable nanoscale layer thickness. This, in turn, facilitates the preparation of particle-reinforced Cu-Cr-Zr alloys with nanoscale Cr particles that exhibit excellent performance in all aspects.

[0029] Furthermore, the extrusion ratio of the secondary extrusion in step E of the preparation method of the present invention is 9-30:1.

[0030] Experiments have verified that the Cu-Cr-Zr alloy prepared by the above-mentioned secondary extrusion has better comprehensive mechanical properties and can produce high-performance Cu alloys with excellent yield strength, tensile strength and elongation. Attached Figure Description

[0031] Figure 1 The tensile curve of the nanoparticle-reinforced Cu-Cr-Zr alloy prepared in Example 5 of this invention is shown.

[0032] Figure 2 This is a SEM image of the as-cast microstructure of the nanoparticle-reinforced Cu-Cr-Zr alloy prepared in step A of Example 5 of the present invention.

[0033] Figure 3This is a SEM image of the semi-solid microstructure of the nanoparticle-reinforced Cu-Cr-Zr alloy prepared in step D of Example 5 of the present invention. Detailed Implementation

[0034] Example 1

[0035] A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method are described below:

[0036] A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 0.81% Cr, 0.13% Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu; the specific operation for preparing the cast Cu-Cr-Zr alloy is as follows: according to the set mass percentage ratio of each component element, place pure Cu in a crucible and heat it to 600℃, then introduce high-purity argon gas. After the pure Cu is completely melted, heat it to 1250℃ and add Cr flakes and Cu-Zr intermediate alloy respectively. Stir for 2 minutes, then remove slag, let it stand for 10 minutes, and when the temperature drops to 1180℃, cast it to obtain the cast Cu-Cr-Zr alloy.

[0037] B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A at 860℃ for 24 hours, and then cool it in the furnace.

[0038] C. After the Cu-Cr-Zr alloy obtained in step B has been annealed, it is held at 900℃ for 4 hours and then hot extruded. The extrusion temperature is 900℃, the extrusion speed is 2mm / s, and the extrusion ratio is 9:1.

[0039] D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace, heat it to 980℃ with the furnace for semi-solid isothermal treatment, hold it for 60 minutes, and then quench it with water at 35℃.

[0040] E. After holding the Cu-Cr-Zr alloy obtained in step D at 700℃ for 4 hours, a second extrusion is performed to obtain a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 700℃, the extrusion speed is 2mm / s, and the extrusion ratio is 9:1.

[0041] The Cu-Cr-Zr alloy prepared in this example has a tensile strength of 634 MPa, a yield strength of 551 MPa, and an elongation of 9.1%.

[0042] Example 2

[0043] A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method are described below:

[0044] A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 0.6% Cr, 0.1% Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu; the specific operation for preparing the cast Cu-Cr-Zr alloy is as follows: according to the set mass percentage ratio of each component element, place pure Cu in a crucible and heat it to 700℃, then introduce high-purity argon gas. After the pure Cu is completely melted, heat it to 1300℃ and add Cr flakes and Cu-Zr master alloy respectively. Stir for 3 minutes, then remove slag, let it stand for 20 minutes, and when the temperature drops to 1220℃, cast it to obtain the cast Cu-Cr-Zr alloy.

[0045] B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A at 900℃ for 12 hours, and then cool it in the furnace.

[0046] C. After the Cu-Cr-Zr alloy obtained in step B has been annealed, it is held at 850℃ for 4 hours and then hot extruded. The extrusion temperature is 850℃, the extrusion speed is 1mm / s, and the extrusion ratio is 15:1.

[0047] D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace, heat it to 1000℃ with the furnace for semi-solid isothermal treatment, hold it for 45 minutes, and then water-quench it. The quenching medium for water-quenching is water at 45℃.

[0048] E. After holding the Cu-Cr-Zr alloy obtained in step D at 720℃ for 4 hours, a second extrusion is performed to obtain a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 720℃, the extrusion speed is 2.5 mm / s, and the extrusion ratio is 15:1.

[0049] The Cu-Cr-Zr alloy prepared in this example has a tensile strength of 606 MPa, a yield strength of 447 MPa, and an elongation of 10.41%.

[0050] Example 3

[0051] A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method are described below:

[0052] A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 0.4% Cr, 0.15% Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu; the specific operation for preparing the cast Cu-Cr-Zr alloy is as follows: according to the set mass percentage ratio of each component element, place pure Cu in a crucible and heat it to 640℃, then introduce high-purity argon gas. After the pure Cu is completely melted, heat it to 1260℃ and add Cr flakes and Cu-Zr master alloy respectively. Stir for 3 minutes, then remove slag, let it stand for 15 minutes, and when the temperature drops to 1210℃, cast it to obtain the cast Cu-Cr-Zr alloy.

[0053] B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A at 880℃ for 18 hours, and then cool it in the furnace.

[0054] C. After the Cu-Cr-Zr alloy obtained in step B has been annealed, it is held at 805℃ for 3 hours and then hot extruded. The extrusion temperature is 805℃, the extrusion speed is 2.5mm / s, and the extrusion ratio is 9:1.

[0055] D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace, heat it to 1010℃ with the furnace for semi-solid isothermal treatment, hold it for 20 minutes, and then water-quench it. The quenching medium for water-quenching is water at 80℃.

[0056] E. After holding the Cu-Cr-Zr alloy obtained in step D at 760℃ for 2 hours, a second extrusion is performed to obtain a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 760℃, the extrusion speed is 0.5mm / s, and the extrusion ratio is 15:1.

[0057] The Cu-Cr-Zr alloy prepared in this example has a tensile strength of 593 MPa, a yield strength of 509 MPa, and an elongation of 8.6%.

[0058] Example 4

[0059] A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method are described below:

[0060] A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 1.61% Cr, 0.2% Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu; the specific operation for preparing the cast Cu-Cr-Zr alloy is as follows: according to the set mass percentage ratio of each component element, place pure Cu in a crucible and heat it to 700℃, then introduce high-purity argon gas. After the pure Cu is completely melted, heat it to 1270℃ and add Cr flakes and Cu-Zr master alloy respectively. Stir for 3.5 min, then remove slag, let it stand for 16 min, and when the temperature drops to 1220℃, cast it to obtain the cast Cu-Cr-Zr alloy.

[0061] B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A at 910℃ for 22h, and then cool it in the furnace.

[0062] C. After the Cu-Cr-Zr alloy obtained in step B has been annealed, it is held at 860℃ for 4 hours and then hot extruded. The extrusion temperature is 860℃, the extrusion speed is 2.5mm / s, and the extrusion ratio is 9:1.

[0063] D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace, heat it to 1020℃ with the furnace for semi-solid isothermal treatment, hold it for 10 minutes, and then water-quench it. The quenching medium for water-quenching is water at 30℃.

[0064] E. After holding the Cu-Cr-Zr alloy obtained in step D at 750℃ for 2 hours, a second extrusion is performed to obtain a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 750℃, the extrusion speed is 0.5mm / s, and the extrusion ratio is 10:1.

[0065] The Cu-Cr-Zr alloy prepared in this example has a tensile strength of 665 MPa, a yield strength of 588 MPa, and an elongation of 6.88%.

[0066] Example 5

[0067] A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method are described below:

[0068] A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is 3.11% Cr, 0.18% Zr, the content of unavoidable impurity elements is ≤0.1%, and the remainder is Cu; the specific operation for preparing the cast Cu-Cr-Zr alloy is as follows: according to the set mass percentage ratio of each component element, place pure Cu in a crucible and heat it to 660°C, then introduce high-purity argon gas. After the pure Cu has completely melted, heat it to 1260°C and add Cr flakes and Cu-Zr master alloy respectively. Stir for 2.5 min, then remove slag, let it stand for 16 min, and when the temperature drops to 1195°C, cast it to obtain the cast Cu-Cr-Zr alloy.

[0069] B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A at 880℃ for 20h, and then cool it in the furnace.

[0070] C. After the Cu-Cr-Zr alloy obtained in step B has been annealed, it is held at 805℃ for 4 hours and then hot extruded. The extrusion temperature is 805℃, the extrusion speed is 3mm / s, and the extrusion ratio is 9:1.

[0071] D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace, heat it to 990℃ with the furnace for semi-solid isothermal treatment, hold it for 30 minutes, and then water-quench it. The quenching medium for water-quenching is water at 20℃.

[0072] E. After holding the Cu-Cr-Zr alloy obtained in step D at 760℃ for 4 hours, a second extrusion is performed to obtain a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 760℃, the extrusion speed is 0.4 mm / s, and the extrusion ratio is 15:1.

[0073] The Cu-Cr-Zr alloy prepared in this example has a tensile strength of 688 MPa, a yield strength of 570 MPa, and an elongation of 5.43%.

[0074] Figure 1 The tensile curve of the nanoparticle-reinforced Cu-Cr-Zr alloy prepared in this embodiment is shown. Figure 2 This is a SEM image of the as-cast microstructure of the nanoparticle-reinforced Cu-Cr-Zr alloy prepared in step A of this embodiment. The gray phase represents the α-Cu matrix, and the black phase represents the eutectic Cr phase. The micron-sized eutectic Cr phase is uniformly distributed in a dotted pattern between the dendrites. Figure 3This is a SEM image of the semi-solid microstructure of the nanoparticle-reinforced Cu-Cr-Zr alloy prepared in step D of this embodiment. After semi-solid isothermal treatment, solute atoms rapidly diffuse and accumulate at the grain boundaries, forming a continuous network eutectic microstructure after rapid quenching. Simultaneously, a partially integrated spheroidized second phase remains within the grains, where the eutectic Cr has been refined to the nanoscale.

[0075] Example 6

[0076] A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method are described below:

[0077] A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 0.2% Cr, 1.0% Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu; the specific operation for preparing the cast Cu-Cr-Zr alloy is as follows: according to the set mass percentage ratio of each component element, place pure Cu in a crucible and heat it to 660℃, then introduce high-purity argon gas. After the pure Cu is completely melted, heat it to 1260℃ and add Cr flakes and Cu-Zr master alloy respectively. Stir for 5 minutes, then remove slag, let it stand for 15 minutes, and when the temperature drops to 1230℃, cast it to obtain the cast Cu-Cr-Zr alloy.

[0078] B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A at 940℃ for 10 hours, and then cool it in the furnace.

[0079] C. After the Cu-Cr-Zr alloy obtained in step B has been annealed, it is held at 800℃ for 2 hours and then hot extruded. The extrusion temperature is 800℃, the extrusion speed is 0.1mm / s, and the extrusion ratio is 15:1.

[0080] D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace, heat it to 900℃ with the furnace for semi-solid isothermal treatment, hold it for 4 hours, and then water-quench it. The quenching medium for water-quenching is water at 80℃.

[0081] E. After holding the Cu-Cr-Zr alloy obtained in step D at 600℃ for 4 hours, a second extrusion is performed to obtain a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 600℃, the extrusion speed is 0.1mm / s, and the extrusion ratio is 30:1.

[0082] Example 7

[0083] A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method are described below:

[0084] A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 4% Cr, 0.1% Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu; the specific operation for preparing the cast Cu-Cr-Zr alloy is as follows: according to the set mass percentage ratio of each component element, place pure Cu in a crucible and heat it to 660℃, then introduce high-purity argon gas. After the pure Cu is completely melted, heat it to 1260℃ and add Cr flakes and Cu-Zr master alloy respectively. Stir for 2.5 min, then remove slag, let it stand for 16 min, and when the temperature drops to 1195℃, cast it to obtain the cast Cu-Cr-Zr alloy.

[0085] B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A at 880℃ for 20h, and then cool it in the furnace.

[0086] C. After the Cu-Cr-Zr alloy obtained in step B has been annealed, it is held at 880℃ for 3 hours and then hot extruded. The extrusion temperature is 880℃, the extrusion speed is 5mm / s, and the extrusion ratio is 30:1.

[0087] D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace, heat it to 1040℃ with the furnace for semi-solid isothermal treatment, hold it for 6 minutes, and then quench it with water at 20℃.

[0088] E. After holding the Cu-Cr-Zr alloy obtained in step D at 760℃ for 4 hours, a second extrusion is performed to obtain a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 760℃, the extrusion speed is 0.4 mm / s, and the extrusion ratio is 15:1.

[0089] Example 8

[0090] A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method are described below:

[0091] A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 3.2% Cr, 0.3% Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu; the specific operation for preparing the cast Cu-Cr-Zr alloy is as follows: according to the set mass percentage ratio of each component element, place pure Cu in a crucible and heat it to 660℃, then introduce high-purity argon gas. After the pure Cu is completely melted, heat it to 1260℃ and add Cr flakes and Cu-Zr master alloy respectively. Stir for 2.5 min, then remove slag, let it stand for 16 min, and when the temperature drops to 1195℃, cast it to obtain the cast Cu-Cr-Zr alloy.

[0092] B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A at 880℃ for 20h, and then cool it in the furnace.

[0093] C. After the Cu-Cr-Zr alloy obtained in step B has been annealed, it is held at 805℃ for 4 hours and then hot extruded. The extrusion temperature is 805℃, the extrusion speed is 3mm / s, and the extrusion ratio is 9:1.

[0094] D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace, heat it to 980℃ with the furnace for semi-solid isothermal treatment, hold it for 30 minutes, and then water-quench it. The quenching medium for water-quenching is water at 30℃.

[0095] E. After holding the Cu-Cr-Zr alloy obtained in step D at 800℃ for 3 hours, a second extrusion is performed to obtain a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 800℃, the extrusion speed is 5mm / s, and the extrusion ratio is 60:1.

[0096] Example 9

[0097] A nanoparticle-reinforced Cu-Cr-Zr alloy and its preparation method are described below:

[0098] A. Prepare a cast Cu-Cr-Zr alloy according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 3.2% Cr, 0.3% Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu; the specific operation for preparing the cast Cu-Cr-Zr alloy is as follows: according to the set mass percentage ratio of each component element, place pure Cu in a crucible and heat it to 660℃, then introduce high-purity argon gas. After the pure Cu is completely melted, heat it to 1260℃ and add Cr flakes and Cu-Zr master alloy respectively. Stir for 2.5 min, then remove slag, let it stand for 16 min, and when the temperature drops to 1195℃, cast it to obtain the cast Cu-Cr-Zr alloy.

[0099] B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A at 880℃ for 20h, and then cool it in the furnace.

[0100] C. After the Cu-Cr-Zr alloy obtained in step B has been annealed, it is held at 805℃ for 4 hours and then hot extruded. The extrusion temperature is 805℃, the extrusion speed is 3mm / s, and the extrusion ratio is 9:1.

[0101] D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace, heat it to 1030℃ with the furnace for semi-solid isothermal treatment, hold it for 1 hour, and then water-quench it. The quenching medium for water-quenching is water at 40℃.

[0102] E. After holding the Cu-Cr-Zr alloy obtained in step D at 760℃ for 4 hours, a second extrusion is performed to obtain a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 760℃, the extrusion speed is 0.4 mm / s, and the extrusion ratio is 15:1.

Claims

1. A method for preparing a nanoparticle-reinforced Cu-Cr-Zr alloy, comprising the following steps: A. Prepare Cu-Cr-Zr alloy ingots according to the set mass percentage ratio of each component element; the set mass percentage ratio of each component element is: 0.2-3.2%Cr, 0.1-0.3%Zr, unavoidable impurity element content ≤0.1%, and the remainder is Cu; B. Anneal the as-cast Cu-Cr-Zr alloy prepared in step A; C. After holding the annealed Cu-Cr-Zr alloy obtained in step B at 800-900℃ for 2-4 hours, hot extrusion is carried out. The extrusion temperature is 800-900℃, the extrusion speed is 0.1-5mm / s, and the extrusion ratio is 9-30:

1. Hot extrusion breaks the eutectic structure with micron-level interlamellar spacing in the Cu-Cr-Zr alloy into micron-level Cr particles. D. Place the hot-extruded Cu-Cr-Zr alloy obtained in step C into a heat treatment furnace and heat it to 980-1030℃ for semi-solid isothermal treatment. Hold it for 0.1-1h to transform the micron-sized Cr particles in the Cu-Cr-Zr alloy into a eutectic (α-Cu+Cr) structure with a lamellar spacing of nanometers. Then, water-quench it. E. After holding the Cu-Cr-Zr alloy obtained in step D at 600-800℃ for 2-4 hours, a second extrusion is performed to break the eutectic (α-Cu+Cr) structure with nanoscale interlamellar spacing in the Cu-Cr-Zr alloy into nanoscale Cr particles, which are dispersed on the α-Cu matrix, thus obtaining a nanoparticle-reinforced Cu-Cr-Zr alloy. The specific operation of the second extrusion is as follows: the extrusion temperature is 600-800℃, the extrusion speed is 0.1-5mm / s, and the extrusion ratio is 9-30:

1.

2. The method for preparing a nanoparticle-reinforced Cu-Cr-Zr alloy according to claim 1, characterized in that: The specific operation for preparing the as-cast Cu-Cr-Zr alloy in step A is as follows: According to the set mass percentage ratio of each component element, pure Cu is placed in a crucible and heated to 600-700℃. High-purity argon gas is introduced. After the pure Cu is completely melted, it is heated to 1250-1300℃ and Cr sheets and Cu-Zr master alloy are added respectively. After stirring for 2-5 minutes, the slag is removed. The mixture is allowed to stand for 10-20 minutes. When the temperature drops to 1180-1230℃, it is poured to obtain the as-cast Cu-Cr-Zr alloy.

3. The method for preparing a nanoparticle-reinforced Cu-Cr-Zr alloy according to claim 1, characterized in that: The annealing temperature for step B is 860-940℃, and the annealing time is 10-24h.

4. The method for preparing a nanoparticle-reinforced Cu-Cr-Zr alloy according to claim 1, characterized in that: In step C, the hot extrusion ratio of the annealed Cu-Cr-Zr alloy obtained in step B is 9-15:

1.

5. The method for preparing a nanoparticle-reinforced Cu-Cr-Zr alloy according to claim 1, characterized in that: In step D, the quenching medium for water-cooled quenching is water at 20-80℃.

6. A nanoparticle-reinforced Cu-Cr-Zr alloy, characterized in that: The nanoparticle-reinforced Cu-Cr-Zr alloy is prepared by any one of the preparation methods according to claims 1-5.

Images