Copper alloy with excellent comprehensive performance and application thereof

Abstract

The invention is a copper alloy with excellent comprehensive performance, including the following components in percentage by weight: 0.4 wt %-2.0 wt % of Ni, 0.2 wt %-2.5 wt % of Sn, 0.02 wt %-0.25 wt % of P, 0.001 wt %-0.5 wt % of Si, and the balance of Cu and unavoidable impurities. The copper alloy has a yield strength of 550 MPa or above, and an electrical conductivity of 38% IACS or above. A bending workability is as follows: the value of R/t in the GW direction is less than or equal to 1, and the value of R/t in the BW direction is less than or equal to 2; and after the copper alloy is kept at 150° C. for 1000 hours, a residual stress rate is greater than or equal to 75%, and the stress relaxation resistance is excellent.

Claims

1. A copper alloy, consisting of the following components in percentage by weight: 0.4 wt %-2.0 wt % of Ni; 0.2 wt %-0.95 wt % of Sn; 0.02 wt %-0.25 wt % of P; 0.001 wt %-0.091 wt % of Si; and the balance of Cu and unavoidable impurities, wherein a microstructure of the copper alloy contains a Ni—P intermetallic compound and a Ni—Si intermetallic compound, wherein average particle diameters of the Ni—P intermetallic compound and the Ni—Si intermetallic compound are both within a range of 5 nm to 50 nm, wherein the weight percentages of Ni, P, and Si satisfy: 3≤Ni/(P+Si)≤20, and the weight percentages of Si and P satisfy: 0.1≤Si/P≤10, wherein the crystal orientations of a strip of the copper alloy satisfies: an area ratio of brass orientation {011}<211> with a deviation angle of less than 15° is 5% to 37%, and an area ratio of S-type orientation {123}<634> with a deviation angle of less than 15° is 5% to 30%.

2. A copper alloy, consisting of the following components in percentage by weight: 0.4 wt %-2.0 wt % of Ni; 0.2 wt %-0.95 wt % of Sn; 0.02 wt %-0.25 wt % of P; 0.001 wt %-0.091 wt % of Si; 0.01 wt %-0.5 wt % of Mg and/or 0.1 wt %-2.0 wt % of Zn; and the balance of Cu and unavoidable impurities, wherein a microstructure of the copper alloy contains a Ni—P intermetallic compound and a Ni—Si intermetallic compound, wherein average particle diameters of the Ni—P intermetallic compound and the Ni—Si intermetallic compound are both within a range of 5 nm to 50 nm, wherein the weight percentages of Ni, P, and Si satisfy: 3≤Ni/(P+Si)≤20, and the weight percentages of Si and P satisfy: 0.1≤Si/P≤10, wherein the crystal orientations of a strip of the copper alloy satisfies: an area ratio of brass orientation {011}<211> with a deviation angle of less than 15° is 5% to 37%, and an area ratio of S-type orientation {123}<634> with a deviation angle of less than 15° is 5% to 30%.

3. A copper alloy, consisting of the following components in percentage by weight: 0.4 wt %-2.0 wt % of Ni; 0.2 wt %-0.95 wt % of Sn; 0.02 wt %-0.25 wt % of P; 0.001 wt %-0.091 wt % of Si; 0.001 wt % to 1.0 wt % of at least one element selected from Fe, Al, Zr, Cr, Mn, B, and RE; and the balance of Cu and unavoidable impurities, wherein a microstructure of the copper alloy contains a Ni—P intermetallic compound and a Ni—Si intermetallic compound, wherein average particle diameters of the Ni—P intermetallic compound and the Ni—Si intermetallic compound are both within a range of 5 nm to 50 nm, wherein the weight percentages of Ni, P, and Si satisfy: 3≤Ni/(P+Si)≤20, and the weight percentages of Si and P satisfy: 0.1≤Si/P≤10, wherein the crystal orientations of a strip of the copper alloy satisfies: an area ratio of brass orientation {011}<211> with a deviation angle of less than 15° is 5% to 37%, and an area ratio of S-type orientation {123}<634> with a deviation angle of less than 15° is 5% to 30%.

4. The copper alloy according to claim 1, wherein a strip of the copper alloy has a yield strength of 550 MPa or above and an electrical conductivity of 38% IACS or above.

5. The copper alloy according to claim 1, wherein a 90° bending workability of a strip of the copper alloy is as follows: a value of R/t in the GW direction is less than or equal to 1, and a value R/t in the BW direction is less than or equal to 2; after the strip of the copper alloy is kept at 150° C. for 1000 hours, a stress residual rate is 75% or above.

Description

DESCRIPTION OF THE EMBODIMENTS

(1) With reference to the embodiments, the invention will be further described in detail below.

(2) Components of copper alloys shown in the composition of various embodiments of Table 1 are smelted at a temperature of 1120° C. to 1200° C. by semi-continuous casting to produce a 440 mm×250 mm ingot. The ingot is kept at 850° C. for 5 hours, and then hot rolled to a thickness of 16.5 mm. Then, due to the surface descaling, the face milling is to be performed, and the upper and lower faces of the hot rolled plate are respectively milled by 0.5 mm-1.0 mm to 15 mm; thereafter, the plate having a thickness of 2 mm is obtained through primary cold rolling; the plate after the primary cold rolling is heated to 400° C. and kept at this temperature for 8 hours for the primary aging. Then, the plate after the primary aging is subjected to secondary cold rolling to the thickness of 0.33 mm, and then kept at 360° C. for 8 hours for secondary aging treatment. Finally, finish rolling is carried out to reach the target thickness of 0.2 mm. After finish rolling, the plate is kept at 240° C. for 4 hours for low-temperature annealing to obtain a strip sample.

(3) For the prepared strip samples of 20 embodiment alloys and 7 reference alloys, mechanical properties, electrical conductivity, stress relaxation resistance, bending workability, crystal orientations, and the average particle diameter of the precipitates are respectively tested.

(4) The room temperature tensile test is carried out in accordance with GB/T 228.1-2010 Metallic Materials-Tensile Tests Part 1: Room Temperature Test Method on an electronic universal mechanical property test machine, using 12.5 mm wide strip end samples, with a tensile speed of 5 mm/Min.

(5) The electrical conductivity test is carried out in accordance with GB/T 3048.2-2007 Wires and Cables-Electrical Property test methods Part 2: Resistivity Tests for Metallic Materials, where the test instrument used is a ZFD microcomputer bridge DC resistance tester, with samples being 20 mm wide and 500 mm long.

(6) The stress relaxation resistance test is carried out in accordance with JCBA T309: 2004 Bending Stress Relaxation Test Methods for Copper and Copper Alloys, where samples which are 10 mm wide and 100 mm long are taken parallel to the rolling direction, the initial loading stress value is 80% of 0.2% yield strength, the test temperature is 150° C., the test time is 1000 h.

(7) The bending property test is carried out on a bending test machine in accordance with GBT 232-2010 Metallic Materials-Bending Test Methods, with samples being 5 mm wide and 50 mm long.

(8) The texture test is carried out on a Pegasus XM2 EBSD device in accordance with GBT 30703-2014 Guidelines for Electron Backscatter Diffraction Orientation Analysis Methods for Microbeam Analysis, with samples being 10 mm wide and 10 mm long.

(9) When the size of the precipitates is tested, the alloy is prepared into a sheet having a diameter of 3 mm, and the structure of the sample is observed by ion-transfer treatment on a transmission electron microscope (the device used is FEI TF20, magnification: 15000), and the average particle diameter of the intermetallic compounds precipitated from the alloy is calculated based on the observation result.

(10) The composition and property results of Embodiments and reference examples are shown in Table 1.

(11) According to the embodiments, it can be found that all the copper alloys of the embodiments of the invention achieve a yield strength of 550 MPa or above, an electrical conductivity of 38% IACS or above, and an excellent bending workability (i.e., the value of R/t in the GW direction is less than or equal to 1, and the value of R/t in the BW direction is less than or equal to 2.

(12) It can be seen from reference examples 1 to 4 that when the ratios of Ni, Si, and P are different, the condition that 3Ni/(Si+P) 20 and 0.1Si/P10 is satisfied, and the properties satisfying the materials required by us cannot be obtained. It can be seen from reference examples 5 and 6 that when the area ratio of the Brass orientation {011}<211> with a deviation angle of less than 15° does not satisfy 5% to 37%, the area ratio of the S-type orientation {123}<634> with a deviation angle of less than 15° does not satisfy 5% to 30%, and the bending workability of the material is significantly deteriorated. It can be seen from reference examples 7 and 8 that when the average particle diameter of the material precipitates does not satisfy 5 nm to 50 nm, the bending workability and the stress relaxation resistance of the alloy are remarkably lowered, and the required material properties cannot be satisfied.

(13) TABLE-US-00001 TABLE 1 Composition and property test results of Embodiments and references Property index Element content/wt % Yield Electrical Ni/ strength conductivity Ni Sn P Si Other Cu (P + Si) Si/P MPa % IACS Embodiment 1 0.89 0.92 0.06 0.020 — Balance 10.8 0.32 557 44.3 Embodiment 2 1.07 0.95 0.13 0.186 — 3.4 1.46 589 42.6 Embodiment 3 0.92 2.21 0.08 0.174 — 3.6 2.18 638 39.1 Embodiment 4 1.31 1.13 0.03 0.172 — 6.5 5.73 615 43.6 Embodiment 5 1.60 1.08 0.08 0.228 — 5.1 2.76 638 41.3 Embodiment 6 0.82 1.76 0.03 0.074 — 7.7 2.23 621 40.2 Embodiment 7 1.94 0.54 0.20 0.365 — 3.4 1.86 632 43.7 Embodiment 8 1.84 1.99 0.11 0.111 — 8.3 1.01 652 38.7 Embodiment 9 1.30 0.79 0.03 0.060 Mg: 0.15 14.4 2.00 605 45.2 Embodiment 10 1.89 1.41 0.14 0.306 Zn: 0.2 4.3 2.24 639 40.4 Embodiment 11 1.90 2.20 0.21 0.212 Fe: 0.18 4.5 1.02 662 38.5 Embodiment 12 0.42 1.53 0.05 0.013 Co: 0.38 6.6 0.26 592 41.7 Embodiment 13 1.84 2.41 0.05 0.046 Al: 0.23 19.0 0.89 661 38.1 Embodiment 14 1.66 2.24 0.10 0.065 Zr: 0.08 10.1 0.65 643 38.5 Embodiment 15 1.00 1.71 0.10 0.211 Cr: 0.18 3.2 2.02 621 41.2 Embodiment 16 1.18 1.97 0.04 0.030 Mn: 0.38 16.9 0.75 637 40.8 Embodiment 17 1.53 1.58 0.18 0.031 B: 0.09 7.1 0.17 638 42.3 Embodiment 18 1.70 0.35 0.04 0.091 RE: 0.05 13.2 2.42 627 43.6 Embodiment 19 1.02 0.99 0.07 0.152 Mn: 0.35 4.7 2.32 602 46.7 Al: 0.08 Embodiment 20 0.75 1.23 0.05 0.150 Zr: 0.05 3.8 3.00 615 41.5 Cr: 0.18 Reference 1.40 1.18 0.03 0.015 — 31.2 0.51 538 41.5 Example 1 Reference 1.17 1.27 0.25 0.31 — 2.1 1.27 649 32.8 Example 2 Reference 1.13 0.83 0.21 0.02 — 4.9 0.09 634 36.9 Example 3 Reference 1.23 1.32 0.03 0.35 — 3.2 11.67 621 36.1 Example 4 Reference 1.47 0.96 0.20 0.03 — 6.6 0.13 610 40.1 Example 5 Reference 1.06 2.09 0.24 0.03 — 4.0 0.11 622 39.5 Example 6 Reference 1.05 0.69 0.05 0.15 5.3 3.00 610 39.5 Example 7 Reference 1.53 1.10 0.07 0.23 5.1 3.29 620 40.5 Example 8 Property index Compound Average Residual Brass S type particle Element Ductility stress 90° Bending Orientation Orientation diameter content/wt % % rate % GW BW Proportion % Proportion % nm Embodiment 1 3 72 0 0.5 19 15 7 Embodiment 2 2 78 0.5 1.5 7 23 22 Embodiment 3 2 77 1 1 32 28 26 Embodiment 4 2 79 1 1.5 13 20 18 Embodiment 5 2 80 1 1.5 25 31 25 Embodiment 6 2 78 0.5 1 30 17 17 Embodiment 7 2 82 0.5 1 19 23 26 Embodiment 8 1 82 1 2 35 29 36 Embodiment 9 2 84 0.5 1 27 28 15 Embodiment 10 2 81 1 2 22 30 40 Embodiment 11 1 82 1 2 36 29 45 Embodiment 12 2 75 0.5 1 31 6 18 Embodiment 13 2 82 1 2 32 26 12 Embodiment 14 2 81 1 2 28 20 19 Embodiment 15 2 77 0.5 1.5 17 28 17 Embodiment 16 2 75 0.5 1 25 24 24 Embodiment 17 2 78 0.5 1.5 26 32 25 Embodiment 18 2 79 0.5 1.5 17 11 37 Embodiment 19 2 79 0.5 1 35 14 25 Embodiment 20 1 75 0.5 1 35 21 16 Reference 2 62 0.5 1 25 8 17 Example 1 Reference 2 72 2 2.5 21 13 26 Example 2 Reference 2 71 0.5 1 19 18 31 Example 3 Reference 2 73 0.5 1 31 29 27 Example 4 Reference 2 76 2 3.5 40 32 24 Example 5 Reference 2 73 2.5 3 15 35 18 Example 6 Reference 2 70 2 2.5 18 19 61 Example 7 Reference 2 68 2 3 25 11 58 Example 8