NANO DISPERSION COPPER ALLOY WITH HIGH AIR-TIGHTNESS AND LOW FREE OXYGEN CONTENT AND BRIEF MANUFACTURING PROCESS THEREOF

Abstract

Disclosed is a nano dispersion copper alloy with high air-tightness and low free oxygen content and a brief manufacturing process thereof, wherein alloy comprises the following components: Al.sub.2O.sub.3, Ca and La. The manufacturing process comprises the following steps of: preparing Cu—Al.sub.2O.sub.3 alloy powder by an internal oxidation method; mixing the Cu—Al.sub.2O.sub.3 alloy powder with Cu—Ca—La alloy powder; sheathing the mixed powder under protection of argon; performing hot extrusion and then rotary forging; vacuumizing the sheath after the rotary forging; and sealing and placing the sheath in a nitrogen atmosphere with a temperature of 450° C. to 550° C. and a pressure intensity of 40 Mpa to 60 Mpa for 3 hours to 5 hours. The dispersion copper prepared by the present disclosure has the advantages of low free oxygen content (≤15 ppm), high dimensional stability, good air-tightness and an air leakage rate≤1.0×10.sup.−10 Pa m.sup.3/s after hydrogen annealing.

Claims

1. A nano dispersion copper alloy with high air-tightness and low free oxygen content, comprising the following components in percentage by mass: 0.05 wt. % to 1.61 wt. % of Al.sub.2O.sub.3, 0.008 wt. % to 0.012 wt. % of Ca, 0.008 wt. % to 0.012 wt. % of La, and the balance of Cu.

2. A brief manufacturing process of the nano dispersion copper alloy with high air-tightness and low free oxygen content, comprising the following steps of: preparing Cu—Al.sub.2O.sub.3 alloy powder by an internal oxidation method; mixing the Cu—Al.sub.2O.sub.3 alloy powder with Cu—Ca—La alloy powder; sheathing the mixed powder under protection of argon; performing hot extrusion at 900° C. to 920° C. and then rotary forging; vacuumizing the sheath to be less than or equal to 10.sup.−3 Pa after the rotary forging; and sealing and placing the sheath in a nitrogen atmosphere with a temperature ranging from 450° C. to 550° C. and a pressure intensity ranging from 40 Mpa to 60 Mpa for 3 hours to 5 hours.

3. The brief manufacturing process of the nano dispersion copper alloy with high air-tightness and low free oxygen content according to claim 2, wherein the internal oxidation method for preparing the Cu—Al.sub.2O.sub.3 alloy powder comprises the following steps of: first step: powder preparation smelting Al and Cu to prepare a Cu—Al alloy melt with an Al content of 0.03 wt. % to 0.8 wt. %, and atomizing the melt to prepare powder; second step: ball-milling activation mixing the powder prepared in the first step with an oxidant for ball-milling activation; third step: graded internal oxidation performing two-grade internal oxidation on the mixture obtained in the second step at 380° C. to 400° C. and 880° C. to 900° C. in a protective atmosphere; and fourth step: reduction crushing the internally oxidized powder obtained in the third step and then reducing with hydrogen to obtain the Cu—Al.sub.2O.sub.3 alloy powder.

4. The brief manufacturing process of the nano dispersion copper alloy with high air-tightness and low free oxygen content according to claim 3, wherein in the first step, a smelting temperature of the alloy is 1200° C. to 1230° C.; and the alloy melt is pulverized by pure nitrogen atomization, and a purity of nitrogen is more than or equal to 99.9%.

5. The brief manufacturing process of the nano dispersion copper alloy with high air-tightness and low free oxygen content according to claim 3, wherein in the second step, alloy powder with a particle diameter less than 40 meshes is mixed with the oxidant for ball-milling; an addition amount of the oxidant accounts for 0.5 wt % to 9.5 wt % of a mass of the alloy powder; and a ball-milling process is as follows: a ratio of ball and material is 3:1 to 10:1, a rotating speed is 50 rpm to 300 rpm, a ball milling time is 120 minutes to 600 minutes, and an atmosphere is air.

6. The brief manufacturing process of the nano dispersion copper alloy with high air-tightness and low free oxygen content according to claim 3, wherein in the third step, parameters of the internal oxidation process are as follows: the ball-milled powder is heated to 380° C. to 400° C. in an argon or nitrogen atmosphere and held for 2 hours to 4 hours, and then the ball-milled power is continuously heated to 880° C. to 900° C. and held for 2 hours to 4 hours.

7. The brief manufacturing process of the nano dispersion copper alloy with high air-tightness and low free oxygen content according to claim 3, wherein in the fourth step, the internally oxidized powder is sieved through a 40-mesh sieve after crushing, and the sieved powder is heated to 880° C. to 900° C. and reduced by hydrogen for 4 hours to 8 hours.

8. The brief manufacturing process of the nano dispersion copper alloy with high air-tightness and low free oxygen content according to claim 2, wherein the preparation method of the Cu—Ca—La alloy powder comprises the following steps of: heating and smelting Cu, Cu—Ca intermediate alloy and La to prepare a Cu—Ca—La alloy melt with a Ca content of 0.08 wt. % to 0.12 wt. % and a La content of 0.08 wt. % to 0.12 wt. %; atomizing the melt with high-purity nitrogen to prepare powder; sieving the powder with a 200-mesh sieve; and performing ball-milling on the sieved powder until a particle diameter of the powder is less than 20 microns to obtain superfine powder; wherein a purity of the high-purity nitrogen is more than or equal to 99.9%.

9. The brief manufacturing process of the nano dispersion copper alloy with high air-tightness and low free oxygen content according to claim 2, wherein the Cu—Ca—La alloy powder and the Cu—Al alloy powder prepared by the internal oxidation method are mixed according to a mass ratio ranging from 1:10 to 1:15, subjected to cold isostatic pressing, sheathed by pure copper in an argon chamber, subjected to water sealing and hot extrusion at 900° C. to 920° C., with an extrusion ratio greater than or equal to 15, then subjected to rotary forging after extrusion; a rotationally forged bar is placed in a new sheath, then the sheath is vacuumized to 10.sup.−3 Pa, sealed, and placed in a nitrogen atmosphere with a pressure intensity ranging from 40 Mpa to 60 Mpa at 450° C. to 550° C. for 3 hours to 5 hours.

10. The brief manufacturing process of the nano dispersion copper alloy with high air-tightness and low free oxygen content according claim 9, wherein the prepared nano dispersion copper alloy has a tensile strength of 330 MPa to 580 MPa at room temperature, an electric conductivity greater than 80% to 97% of IACS, a free oxygen content less than or equal to 15 ppm, and an air leakage rate less than or equal to 1.0×10.sup.−10 Pa m.sup.3/s.

11. The brief manufacturing process of the nano dispersion copper alloy with high air-tightness and low free oxygen content according claim 9, wherein the diameter of prepared nano dispersion copper alloy of φ20 mm is changed by 0.00 μm before and after annealing with hydrogen at 900° C. for 1 hour through measurement by a spiral micrometer.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiment 1

[0037] A Cu-0.1 wt % Ca-0.1 wt % La alloy was smelted under inert gas protection at 1200° C., atomized with high-purity nitrogen, sieved, and then subjected to high-energy ball milling to obtain superfine powder (an average particle diameter was less than or equal to 20 microns). Al and Cu were smelted at 1218° C. to 1230° C. to obtain a Cu—Al alloy with an Al content of 0.04 wt %. The Cu—Al alloy was atomized with high-purity nitrogen, and sieved to obtain alloy powder with a particle diameter less than 40 meshes. The alloy powder was mixed with an oxidant, subjected to ball milling, internally oxidized with the oxidant at 386° C. to 395° C. for 2 hours, and then internally oxidized at 892° C. to 900° C. for 3 hours. The internally oxidized powder above was crushed, reduced with hydrogen at 885° C. to 893° C. for 6 hours, mixed with Cu—Ca—La alloy superfine powder according to a ratio of 15:1. The mixed powder above was subjected to cold isostatic pressing, sheathed by pure copper in an argon chamber, and subjected to water sealing and hot extrusion at 900° C., with an extrusion ratio of 15:1, and then subjected to rotary forging after extrusion. The rotationally forged bar was placed in a new sheath, then the sheath was vacuumized to 10.sup.−3 Pa, sealed and placed in a nitrogen atmosphere with a pressure of 40 Mpa at 480° C. for 3 hours. A free oxygen content was less than or equal to 11 ppm (the free oxygen content was detected by a nitrogen/oxygen analyzer TC-436 manufactured by LECO Company of the United States), and properties of the alloy were shown in Table 1.

TABLE-US-00001 TABLE 1 Yield Strength, Tensile Strength, Elongation and Electric Conductivity at Different Test Temperatures Yield Tensile Percentage Electric Air leakage strength strength reduction of area A conductivity rate (MPa) (MPa) (%) (% IACS) (Pa m.sup.3/s) 325 345 13.6 96.2 3.2 × 10.sup.−11

Embodiment 2

[0038] A Cu-0.1 wt % Ca-0.1 wt % La alloy was smelted under inert gas protection at 1200° C., atomized with high-purity nitrogen, sieved, and then subjected to high-energy ball milling to obtain superfine powder (an average particle diameter was less than or equal to 20 microns). Al and Cu were smelted at 1200° C. to 1222° C. to obtain a Cu—Al alloy with an Al content of 0.12 wt %. The Cu—Al alloy was atomized with high-purity nitrogen, and sieved to obtain alloy powder with a particle diameter less than 40 meshes. The alloy powder was mixed with an oxidant, subjected to ball milling, internally oxidized with the oxidant at 392° C. to 400° C. for 2 hours, and then internally oxidized at 893° C. to 898° C. for 3 hours. The internally oxidized powder above was crushed, reduced with hydrogen at 895° C. to 900° C. for 6 hours, mixed with Cu—Ca—La alloy superfine powder according to a ratio of 13:1. The mixed powder above was subjected to cold isostatic pressing, sheathed by pure copper in an argon chamber, and subjected to water sealing and hot extrusion at 900° C., with an extrusion ratio of 15:1, and then subjected to rotary forging after extrusion. The rotationally forged bar was placed in a new sheath, then the sheath was vacuumized to 10.sup.−3 Pa, sealed, and placed in a nitrogen atmosphere with a pressure of 50 Mpa at 500° C. for 3 hours. A free oxygen content was less than or equal to 12 ppm (the free oxygen content was detected by a nitrogen/oxygen analyzer TC-436 manufactured by LECO Company of the United States), and properties of the alloy were shown in Table 2.

TABLE-US-00002 TABLE 2 Yield Strength, Tensile Strength, Elongation, Electric Conductivity and Air Leakage Rate Yield Tensile Percentage Electric Air leakage strength strength reduction of area A conductivity rate (MPa) (MPa) (%) (% IACS) (Pa m.sup.3/s) 345 376 12.5 92.2 5.1 × 10.sup.−11

Embodiment 3

[0039] A Cu-0.1 wt % Ca-0.1 wt % La alloy was smelted under inert gas protection at 1200° C., atomized with high-purity nitrogen, sieved, and then subjected to high-energy ball milling to obtain superfine powder (an average particle diameter was less than or equal to 20 microns). Al and Cu were smelted at 1215° C. to 1230° C. to obtain a Cu—Al alloy with an Al content of 0.30 wt %. The Cu—Al alloy was atomized with high-purity nitrogen, and sieved to obtain alloy powder with a particle diameter less than 40 meshes. The alloy powder was mixed with an oxidant, subjected to ball milling, internally oxidized with the oxidant at 382° C. to 393° C. for 2 hours, and then internally oxidized at 887° C. to 896° C. for 3 hours. The internally oxidized powder above was crushed, reduced with hydrogen at 892° C. to 898° C. for 6 hours, mixed with Cu—Ca—La alloy superfine powder according to a ratio of 10:1. The mixed powder above was subjected to cold isostatic pressing, sheathed by pure copper in an argon chamber, and subjected to water sealing and hot extrusion at 900° C., with an extrusion ratio of 15:1, and then subjected to rotary forging after extrusion. The rotationally forged bar was placed in a new sheath, then the sheath was vacuumized to 10.sup.−3 Pa, sealed, and placed in a nitrogen atmosphere with a pressure of 50 Mpa at 520° C. for 3 hours. A free oxygen content was less than or equal to 12 ppm (the free oxygen content was detected by a nitrogen/oxygen analyzer TC-436 manufactured by LECO Company of the United States), and properties of the alloy were shown in Table 3.

TABLE-US-00003 TABLE 3 Yield Strength, Tensile Strength, Elongation and Electric Conductivity Yield Tensile Percentage Electric Air leakage strength strength reduction of area A conductivity rate (MPa) (MPa) (%) (% IACS) (Pa m.sup.3/s) 490 520 12.5 87.8 8.7 × 10.sup.−11

Embodiment 4

[0040] A Cu-0.1 wt % Ca-0.1 wt % La alloy was smelted under inert gas protection at 1200° C., atomized with high-purity nitrogen, sieved, and then subjected to high-energy ball milling to obtain superfine powder (an average particle diameter was less than or equal to 20 microns). Al and Cu were smelted at 1215° C. to 1228° C. to obtain a Cu—Al alloy with an Al content of 0.8 wt %. The Cu—Al alloy was atomized with high-purity nitrogen, and sieved to obtain alloy powder with a particle diameter less than 40 meshes. The alloy powder was mixed with an oxidant, subjected to ball milling, internally oxidized with the oxidant at 388° C. to 400° C. for 2 hours, and then internally oxidized at 886° C. to 894° C. for 3 hours. The internally oxidized powder above was crushed, reduced with hydrogen at 885° C. to 893° C. for 6 hours, mixed with Cu—Ca—La alloy superfine powder according to a ratio of 15:1. The mixed powder above was subjected to cold isostatic pressing, sheathed by pure copper in an argon chamber, and subjected to water sealing and hot extrusion at 900° C., with an extrusion ratio of 15:1, and then subjected to rotary forging after extrusion. The rotationally forged bar was placed in a new sheath, then the sheath was vacuumized to 10.sup.−3 Pa, sealed, and placed in a nitrogen atmosphere with a pressure of 60 Mpa at 550° C. for 3 hours. A free oxygen content was less than or equal to 14 ppm (the free oxygen content was detected by a nitrogen/oxygen analyzer TC-436 manufactured by LECO Company of the United States), and properties of the alloy were shown in Table 4.

TABLE-US-00004 TABLE 4 Tensile Strength, Elongation, Electric Conductivity and Yield Strength at Different Test Temperatures Test Tensile Electric Air leakage temperature strength Elongation conductivity rate (° C.) (MPa) (%) (% IACS) (Pa m.sup.3/s) 25 568 9.7 80.0 9.6 × 10.sup.−11 700 261 7.1 /