Nano Dispersion Copper Alloy Air-Tightness Process
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Solution Overview
Problem
Existing Cu—Al2O3 nano dispersion copper alloys prepared by internal oxidation methods suffer from high residual free oxygen content and low air-tightness, leading to issues such as micropore generation and cathode poisoning in high-vacuum conditions, which are not adequately addressed by current manufacturing processes.
Innovation Solution
A Cu—Al2O3—CaO—La2O3 nano dispersion copper alloy is developed using a gas-solid secondary reduction process combined with vacuum medium-temperature creep deformation, which reduces residual free oxygen content and enhances air-tightness through the addition of Ca and La, and subsequent processing steps like hot extrusion and rotary forging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If internal oxidation method is used to prepare Cu-Al2O3 nano dispersion copper alloy, then the alloy achieves high strength and high conductivity, but the residual free oxygen content remains high and air-tightness is low
Solution Approach 1:
The patent applies parameter changes by introducing vacuum medium-temperature creep deformation as a new processing parameter. The alloy is subjected to vacuum treatment at temperatures between 200-400°C for 1-24 hours, which changes the physical state and removes free oxygen without affecting the Al2O3 dispersion structure. This resolves the contradiction by adjusting process parameters to eliminate harmful oxygen while preserving the strengthening effect.
Solution Approach 2:
The patent uses vacuum treatment as an inert environment to remove free oxygen from the alloy. By creating a vacuum atmosphere during the creep deformation process, the free oxygen is extracted from the copper matrix without introducing new contaminants. This inert environment approach successfully reduces residual oxygen content while maintaining the alloy's high strength and conductivity properties.
2Quantity of substance
If hydrogen reduction is used to remove residual Cu2O, then the alloy conductivity is improved, but free oxygen content remains high due to incomplete reduction
Solution Approach 1:
The patent applies preliminary action by performing vacuum medium-temperature creep deformation before final alloy processing. This preliminary vacuum treatment removes free oxygen that would otherwise require extensive hydrogen reduction. By addressing the oxygen removal issue earlier in the process chain, the subsequent hydrogen reduction step becomes more effective and complete, resolving the manufacturing difficulty of achieving thorough reduction.
Solution Approach 2:
The patent replaces the chemical reduction mechanism (hydrogen reduction) with a physical removal mechanism (vacuum creep deformation). Instead of relying on hydrogen to chemically reduce and remove oxygen, the vacuum process physically extracts free oxygen through creep deformation at medium temperatures. This substitution makes the oxygen removal process more complete and controllable.
3Shape
If hot extrusion and cold working are performed to form the alloy, then the alloy achieves desired shape and density, but micropores are generated due to incongruity deformations of Al2O3 and Cu
Solution Approach 1:
The patent applies beforehand cushioning by performing vacuum medium-temperature creep deformation before hot extrusion and cold working. This preliminary treatment removes free oxygen and reduces the susceptibility to micropore formation during subsequent deformation processes. By cushioning against the formation of defects in advance, the alloy maintains high manufacturing precision while achieving the desired shape through extrusion and working.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resulting alloy achieves a significant reduction in free oxygen content to ≤15 ppm, improved air-tightness with an air leakage rate ≤1.0×10−10 Pa m3/s, and maintains high strength and conductivity, making it suitable for advanced applications like sealing devices and high-voltage direct-current relays.
Implementation Method 1
a gas-solid secondary reduction is utilized to reduce a residual free oxygen content, and an alloy is further densified through vacuum medium-temperature creep deformation to finally obtain a Cu—Al2O3—CaO—La2O3 nano dispersion copper alloy with low oxygen
Implementation Method 2
gas-solid secondary reduction is utilized to reduce a residual free oxygen content, and an alloy is further densified through vacuum medium-temperature creep deformation
Implementation Method 3
a solute element Al is preferentially oxidized by oxygen diffused and infiltrated on a surface to generate Al2O3
Implementation Method 4
a solute element Al is preferentially oxidized by oxygen diffused and infiltrated on a surface
Implementation Method 5
composite powder is reduced in hydrogen, residual Cu2O is removed
Data Source
AI summary
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: Al2O3, Ca and La. The manufacturing process comprises the following steps of: preparing Cu—Al2O3 alloy powder by an internal oxidation method; mixing the Cu—Al2O3 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≤1.0×10−10 Pa m3/s after hydrogen annealing.