CN101240387A - Cu-Al2O3 nano strengthened dispersion alloy and preparation method thereof - Google Patents

Abstract

The invention relates to a Cu-Al2O3 nanometer dispersion strengthening alloy and preparation thereof. The preparation includes the steps of Cu-Al alloy vacuum smelting, pulverizing, screening, internal oxidizing, hydrogen reducing, vacuum hot pressing, canned hot extruding, etc. Comparing with oxygen-free copper, sigma of the alloy of the invention is 2 to 6 times higher that of the oxygen-free copper, the anti-annealing softening temperature is up to over 900 DEG C, the conductivity is up to 96% IACA and more. The process of the invention is simple, the prepared Cu-Al2O3 nanometer dispersion strengthening alloy has high strength, high conductivity, electrical conductivity higher than 96% IACA, and is anti-annealing and antimagnetic. The alloy can not only used for large-scale integrated circuit lead frame, manufacturing of controlled thermonuclear reaction heat sink components, and is expecially suitable for manufacturing of microwave tube grid mesh, inertial instrument sensor, particle accelerator and other high-precise parts.

Description

A kind of Cu-Al 2O 3Nano strengthened dispersion alloy and preparation method thereof

Technical field

The present invention relates to a kind of Cu-Al ₂O ₃Nano strengthened dispersion alloy and preparation method thereof belongs to Nanoalloy material technology field.

Background technology

Annealed state fine copper (as C10100, TU1 etc.) though electroconductibility high (98～102%IACS), the too low (σ of intensity _0.240MPa only), because its yield strength is low, make oxygen free copper be easy to distortion.The high-conductivity copper alloy of development in recent years such as Cu-Zr, Cu-B, Cu-Ag etc., electric conductivity can reach more than the 98%IACS, but after the high temperature annealing stabilization treatment, σ _0.2Can only reach 80Mpa, yield strength is lower, influences it in industrial application.Precipitation strength type copper alloy is as Cu-Cr-Zr, Cu-Ni-Si, Cu-Fe-P etc., though intensity index can reach σ under the cold working aging state _b=500MPa, σ _0.2=450MPa, but electric conductivity is on the low side, only is about 75%IACS, this alloy is after high temperature annealing stability is handled, and intensity and electric conductivity all sharply descend, and can only reach σ _b=280MPa, σ _0.2=80MPa, electric conductivity is about 60%IACS.Specific conductivity such as berylliumbronze, market brass, bronze are many about 10～50%IACS.Nano dispersion reinforced copper alloy is the copper alloy that a class has high strength, high conduction, high temperature resistance annealing softening characteristic, Cu-Al ₂O ₃Alloy is its important class.Just because of having these excellent specific properties, Cu-Al ₂O ₃Alloy is suitable for the manufacturing of the heat sink parts of controlled thermonuclear reaction, also is particularly suitable for application such as microwave tube aperture plate, inertia type instrument transmitter, the contour precision part of particle accelerator.

Cu-Al ₂O ₃The production method of alloy mainly contains internal oxidation, the main points of internal oxidation are that the Cu-Al powdered alloy is placed on oxidation in the oxidizing atmosphere, the high purification technique of alloy can make the disperse copper alloy under the prerequisite that keeps high strength, anti-annealing softening, increases substantially its electroconductibility.Number of C u-Al is disclosed both at home and abroad ₂O ₃The technology of preparing of alloy, wherein typical patent has: US5,551,970, US5071618, JP8109422-A, EP364295-A, US4315777, CN1563447-A, JP7062467-A etc.The method of these patent disclosures can be summarized as follows: with Cu-Al powdered alloy and Cu ₂O (oxygenant) powder is by generating Al ₂O ₃Required chemistry is than mixing, and packs in the container in 850 ℃～950 ℃ insulation 0.5～1h with pulverulence, utilizes Cu ₂O emits oxygen and makes in the Cu-Al powdered alloy and be oxidized to Cu-Al ₂O ₃Powder is removed Cu-Al through 800 ℃～900 ℃ 1h hydrogen reducings again ₂O ₃Residual oxygen in powder or the powder billet.The method that patent JP7062467-A proposes is oxide powder and the Al with copper ₂O ₃Particle powder carries out ball milling to be mixed, and adds deoxidation constituent element C or B in 400 ℃ of reducing atmospheres, goes back the oxide compound of native copper, and die mould, sintering prepare Cu-Al then ₂O ₃Alloy, patent JP8109422-A have also proposed similar method.In above-mentioned each method, Cu-Al ₂O ₃Powdered alloy or powder billet are processed into fine and close Cu-Al through subsequent handlings such as hot extrusions ₂O ₃Alloy material.

In the inertia type instrument field, the material that the material that is used for rotor sensor etc. not only needs to make it has high strength and this material still can keep high strength after standing 900 ℃ of annealing, to prevent that its distortion from rub float and stator, float rotates dumb, even stuck float, also can cause gyrostatic output accuracy and reliability in addition, and require this material to have high conduction performance, specific conductivity should be higher than 96%IACS, but in above-mentioned patent, all do not provide the Cu-Al that specific conductivity is higher than 96%IACS ₂O ₃The composition of alloy and preparation technology.。

Summary of the invention

The objective of the invention is to overcome the deficiency of prior art and a kind of Cu-Al that high strength, high conduction, anti-annealing, no magnetic, specific conductivity are higher than 96%IACS that has is provided ₂O ₃Nano dispersion reinforced copper alloy and preparation method thereof.

A kind of Cu-Al of the present invention's---- ₂O ₃Nano strengthened dispersion alloy, its composition range is: Al ₂O ₃: 0.03～0.08wt%, surplus is Cu.

A kind of Cu-Al of the present invention's---- ₂O ₃The preparation method of nano strengthened dispersion alloy comprises the steps:

(1) Cu-Al alloy vacuum melting

Vacuum tightness 1 * 10 is melted in electrolytic copper oven dry back in vacuum oven ^-1Pa～1 * 10 ^-2Pa; 1150 ℃～1250 ℃ of temperature of fusion contain 0.03～0.07wt%Al by final alloy ₂O ₃Ratio add 0.016～0.037wt% aluminium, molten even back forms the Cu-Al alloy melt;

(2) atomizing

(1) step Cu-Al alloy melt that obtains is heated to 1300 ℃～1350 ℃, in atomisation unit, with greater than 6 * 10 ⁵The Pa high-purity N ₂Gas is atomized into the Cu-Al powdered alloy with the Cu-Al alloy melt.

(3) screening

With the Cu-Al powdered alloy fragmentation of (2) step atomizing gained, screening is got the powder of 70～100 μ m granularities and is done the use of internally oxidized alloy powder.

(4) interior oxidation

With the Cu-Al powdered alloy and the oxygenant batch mixing of (3) step screening gained, oxygenant is Cu ₂O prepares burden behind abundant batch mixing, in the encloses container of packing into, and at N ₂Be heated to 850 ℃～950 ℃ interior oxidations of carrying out 0.5～1h under the condition of protection, form Cu-CuO-Al ₂O ₃Alloy powder.

Proportion scale is n=8C by formula ₂M/9C ₁Calculate;

N-oxygenant quality in the formula, m-Cu-Al alloy powder quality, C ₁Al mass content in the-Cu-Al alloy powder, C ₂Oxygen mass content in the-oxygenant,

(5) hydrogen once reduces

With the Cu-CuO-Al after the oxidation in (4) step ₂O ₃The powder of 70～100 μ m granularities is got in alloy powder fragmentation, screening, in the hydrogen reducing furnace reduction, gets Cu-Al ₂O ₃Alloy powder;

Reductive condition is: 800 ℃～900 ℃ of temperature, time 0.5～1.5h; Reductive hydrogen is High Purity Hydrogen, and dew point is below-40 ℃.

(6) isostatic cool pressing

With (5) step gained Cu-Al ₂O ₃The alloy powder compound carries out isostatic cool pressing, and the density of control pressed compact is in 60～80% scopes.

(7) hydrogen secondary reduction

The billet that suppresses of (6) step is encapsulated in two ends is provided with the fine copper of fine copper communicating pipe and coats in the housing, reduce in hydrogen reducing furnace, reductive condition is: 800 ℃～900 ℃ of temperature, time 0.5～1.5h; After sealing an end, vacuumize, when vacuum tightness reaches 5 * 10 ^-2Behind the Pa, seal the other end.

(8) hot extrusion

At N ₂Protective condition is heated to 850～950 ℃ with (7) step gained billet down, is hot extruded into bar; Extrusion ratio during hot extrusion should be greater than 30: 1.

The present invention forms billet owing to adopt above-mentioned processing method by atomizing, interior oxidation, once reduction of hydrogen, isostatic cool pressing, hydrogen secondary reduction, and at this moment, Al is with nano level Al ₂O ₃Form all from copper, separate out, and distribute copper matrix height purifying in the mode of disperse; By hot extrusion, obtain the hot extrusion bar of powder particle with the metallurgy combinations of states, the copper matrix height purifying in the bar, thus make alloy have high specific conductivity; Nanometer Al ₂O ₃Particle distributes with disperse state, and heat-resistant stability with height, at high temperature also be difficult to grow up, dislocation is played the intensive pinning effect, hindered the rearrangement of deforming alloy dislocation when high temperature annealing effectively, made dispersion strengthening copper alloy when high temperature annealing, be difficult to recrystallize takes place and have excellent high temperature resistance softening power; The crystal grain or the subgrain of alloy are of a size of micron order, thereby it has dispersion-strengthened and refined crystalline strengthening and keeps high intensity.The alloy that adopts the present invention to obtain, (as C10100, TU1) compares with oxygen free copper, has the performance advantage of high strength, high temperature resistance annealing softening, its σ _0.2Higher 2～6 times than oxygen free copper, anti-annealing softening temperature can be up to more than 900 ℃, and electric conductivity can reach more than the 96%IACS.With Cu-Fe-P system, Cu-Ni-Si system, Cu-Cr-Zr be precipitation strength type alloy phase ratio, under the suitable situation of intensity, Cu-Al ₂O ₃Alloy conductive will obviously improve, and has much higher high temperature resistance annealing softening performance.Simple, the prepared Cu-Al of processing method of the present invention ₂O ₃Nano strengthened dispersion alloy has high strength, high conduction, resists annealing, no magnetic, specific conductivity to be higher than the premium properties of 96%IACS, its alloy not only can be applicable to the manufacturing of large-scale integrated circuit lead frame, the heat sink parts of controlled thermonuclear reaction, also is particularly suitable for the manufacturing of microwave tube aperture plate, inertia type instrument transmitter, the contour precision part of particle accelerator.

Embodiment

Embodiment 1: alloy ingredient is Al ₂O ₃-0.055wt%, all the other are Cu and inevitable impurity.By the processing step of the inventive method (1)～(6), make the hot pressing billet of Φ 195.Cu-Al ₂O ₃Pressed compact relative density 70% after the alloy powder control of density isostatic cool pressing.Jacket pressed compact behind the hydrogen secondary reduction is heated to 950 ℃ of bars (extrusion ratio 30: 1) that are hot extruded into Φ 36 under the nitrogen protection condition; and cold forging is to the bar of Φ 25; cold drawn bar through the hydrogen shield annealing of 900 ℃/1h, records alloy property data such as table 1 again.

Table 1

	σ b(MPa)	σ 0.2(MPa)	δ 5 (％)	g (％IACS)	|x D|cm 3/g(C.G.S.M)
						The annealing of 900 ℃/1h hydrogen shield	290	130	30	96.5	4.9×10 -6

Embodiment 2: alloy ingredient is Al ₂O ₃-0.05wt%, all the other are Cu and inevitable impurity.By the processing step of the inventive method (1)～(6), make the hot pressing billet of Φ 195.Cu-Al ₂O ₃Pressed compact relative density 70% after the alloy powder control of density isostatic cool pressing.Jacket pressed compact behind the hydrogen secondary reduction is heated to 950 ℃ of bars (extrusion ratio 30: 1) that are hot extruded into Φ 36 under the nitrogen protection condition; and cold forging is to the bar of Φ 25; cold drawn bar through the hydrogen shield annealing of 900 ℃ of 1h, records alloy property data such as table 2 again.

Table 2

	σ b(MPa)	σ 0.2 (MPa)	δ 5 (％)	g (％IACS)	|x D|cm 3/g(C.G.S.M)
						The annealing of 900 ℃/1h hydrogen shield	280	123	35	97.1	4.9×10 -6

Embodiment 3: alloy ingredient is Al ₂O ₃-0.05wt%, all the other are Cu and inevitable impurity.By the processing step of the inventive method (1)～(6), make the hot pressing billet of Φ 195.Cu-Al ₂O ₃Pressed compact relative density 70% after the alloy powder control of density isostatic cool pressing.Jacket pressed compact behind the hydrogen secondary reduction is heated to 950 ℃ of bars (extrusion ratio 30: 1) that are hot extruded into Φ 36 under the nitrogen protection condition; and cold forging is to the bar of Φ 20; cold drawn bar through the hydrogen shield annealing of 900 ℃ of 1h, records alloy property data such as table 3 again.

Table 3

	σ b(MPa)	σ 0.2 (MPa)	δ 5(％)	g (％IACS)	|x D|cm 3/g(C.G.S.M)
						The annealing of 900 ℃/1h hydrogen shield	285	127	32	97.0	4.9×10 -6

Embodiment 4: alloy ingredient is Al ₂O ₃-0.04wt%, all the other are Cu and inevitable impurity.By the processing step of the inventive method (1)～(6), make the hot pressing billet of Φ 195.Cu-Al ₂O ₃Pressed compact relative density 70% after the alloy powder control of density isostatic cool pressing.Jacket pressed compact behind the hydrogen secondary reduction is heated to 950 ℃ of bars (extrusion ratio 30: 1) that are hot extruded into Φ 36 under the nitrogen protection condition; and cold forging is to the bar of Φ 25; cold drawn bar through the hydrogen shield annealing of 900 ℃ of 1h, records alloy property data such as table 4 again.

Table 4

	σ b(MPa)	σ 0.2(MPa)	δ 5 (％)	g (％IACS)	|x D|cm 3/g(C.G.S.M)
						900 ℃ of 1h hydrogen shield annealing	276	122	35	97.1	4.9×10 -6

Embodiment 5: alloy ingredient is Al ₂O ₃-0.03wt%, all the other are Cu and inevitable impurity.By the processing step of the inventive method (1)～(6), make the hot pressing billet of Φ 195.Cu-Al ₂O ₃Pressed compact relative density 70% after the alloy powder control of density isostatic cool pressing.Jacket pressed compact behind the hydrogen secondary reduction is heated to 950 ℃ of bars (extrusion ratio 30: 1) that are hot extruded into Φ 36 under the nitrogen protection condition; and cold forging is to the bar of Φ 25; cold drawn bar through the hydrogen shield annealing of 900 ℃/1h, records alloy property data such as table 5 again.

Table 5

	σ b(MPa)	σ 0.2 (MPa)	δ 5 (％)	g (％IACS)	|x D|cm 3/g(C.G.S.M)
						The annealing of 900 ℃/1h hydrogen shield	255	110	40	97.3	4.9×10 -6

Embodiment 6: alloy ingredient is Al ₂O ₃-0.08wt%, all the other are Cu and inevitable impurity.By the processing step of the inventive method (1)～(6), make the hot pressing billet of Φ 195.Cu-Al ₂O ₃Pressed compact relative density 70% after the alloy powder control of density isostatic cool pressing.Jacket pressed compact behind the hydrogen secondary reduction is heated to 950 ℃ of bars (extrusion ratio 30: 1) that are hot extruded into Φ 36 under the nitrogen protection condition; and cold forging is to the bar of Φ 25; through the hydrogen shield annealing of 900 ℃/1h, it is as shown in table 6 to record the alloy property data again for cold drawn bar.

Table 6

	σ b(MPa)	σ 0.2(MPa)	δ 5 (％)	g (％IACS)	|x D|cm 3/g(C.G.S.M)
						The annealing of 900 ℃/1h hydrogen shield	310	200	25	96.0	4.9×10 -6

Claims (2)

1, a kind of Cu-Al ₂O ₃Nano strengthened dispersion alloy, its composition range is: Al ₂O ₃: 0.03～0.08wt%, surplus is Cu.

2, a kind of Cu-Al ₂O ₃The preparation method of nano strengthened dispersion alloy comprises the steps:

(1) Cu-Al alloy vacuum melting

Vacuum tightness 1 * 10 is melted in electrolytic copper oven dry back in vacuum oven ^-1Pa～1 * 10 ^-2Pa; 1150 ℃～1250 ℃ of temperature of fusion contain 0.03～0.07wt%Al by final alloy ₂O ₃Ratio add 0.016～0.037wt% aluminium, molten even back forms the Cu-Al alloy melt;

(2) atomizing

(1) step Cu-Al alloy melt that obtains is heated to 1300 ℃～1350 ℃, in atomisation unit, with greater than 6 * 10 ⁵The Pa high-purity N ₂Gas is atomized into the Cu-Al powdered alloy with the Cu-Al alloy melt.

(3) screening

With the Cu-Al powdered alloy fragmentation of (2) step atomizing gained, screening is got the powder of 70～100 μ m granularities and is done the use of internally oxidized alloy powder.

(4) interior oxidation

With the Cu-Al powdered alloy and the oxygenant batch mixing of (3) step screening gained, oxygenant is Cu ₂O prepares burden behind abundant batch mixing, in the encloses container of packing into, and at N ₂Be heated to 850 ℃～950 ℃ interior oxidations of carrying out 0.5～1h under the condition of protection, form Cu-CuO-Al ₂O ₃Alloy powder.

Proportion scale is n=8C by formula ₂M/9C ₁Calculate;

N-oxygenant quality in the formula, m-Cu-Al alloy powder quality, C ₁Al mass content in the-Cu-Al alloy powder, C ₂Oxygen mass content in the-oxygenant,

(5) hydrogen once reduces

With the Cu-CuO-Al after the oxidation in (4) step ₂O ₃The powder of 70～100 μ m granularities is got in alloy powder fragmentation, screening, in the hydrogen reducing furnace reduction, gets Cu-Al ₂O ₃Alloy powder;

Reductive condition is: 800 ℃～900 ℃ of temperature, time 0.5～1.5h; Reductive hydrogen is High Purity Hydrogen, and dew point is below-40 ℃.

(6) isostatic cool pressing

With (5) step gained Cu-Al ₂O ₃The alloy powder compound carries out isostatic cool pressing, and the density of control pressed compact is in 60～80% scopes.

(7) hydrogen secondary reduction

The billet that suppresses of (6) step is encapsulated in two ends is provided with the fine copper of fine copper communicating pipe and coats in the housing, reduce in hydrogen reducing furnace, reductive condition is: 800 ℃～900 ℃ of temperature, time 0.5～1.5h; After sealing an end, vacuumize, when vacuum tightness reaches 5 * 10 ^-2Behind the Pa, seal the other end.

(8) hot extrusion

At N ₂Protective condition is heated to 850～950 ℃ with (7) step gained billet down, is hot extruded into bar; Extrusion ratio during hot extrusion should be greater than 30: 1.