Ag-Based Oxide Contact Material with Oriented Particles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for preparing Ag-based oxide contact materials with small reinforcing particles often result in poor dispersivity, leading to increased electrical resistance, reduced ductility, and processing difficulties, while also compromising arc ablation resistance and electrical conductivity.
Innovation Solution
A method involving chemical co-precipitation followed by high energy ball milling, sieving, and directional hot extrusion to achieve evenly dispersed and directionally arranged reinforcing particles within the Ag matrix, enhancing particle connectivity and forming a fiber-like structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If chemical co-precipitation method is used to prepare composite powder, then reinforcing particles can be dispersedly distributed in Ag matrix, but electrical resistance is greatly increased due to electron scattering effect
Solution Approach 1:
The patent applies local quality by creating two distinct particle distribution zones: dispersed fine particles for arc ablation resistance and directionally arranged elongated particles for electrical conductivity. The directional arrangement along the extrusion direction ensures electron transport pathways are maintained, while the dispersed fine particles provide local protection against arc erosion without causing excessive electron scattering.
Solution Approach 2:
The patent transitions from isotropic particle distribution to anisotropic directional arrangement through hot extrusion. The elongated particles are oriented along the extrusion direction, creating a dimensionally structured distribution that simultaneously achieves good electrical conductivity along the orientation direction and uniform arc ablation resistance across the contact surface.
2Strength
If reinforcing particles are dispersively distributed to improve intensity and hardness, then resistance to mechanical wear is improved, but elongation is greatly decreased resulting in poor ductility
Solution Approach 1:
The patent applies local quality by creating two distinct particle distribution zones: dispersed fine particles for arc ablation resistance and directionally arranged elongated particles for electrical conductivity. The directional arrangement along the extrusion direction ensures electron transport pathways are maintained, while the dispersed fine particles provide local protection against arc erosion without causing excessive electron scattering.
Solution Approach 2:
The patent uses composite materials by combining Ag matrix with dual-phase oxide particles (fine dispersed particles and elongated directionally arranged particles). This composite structure integrates the benefits of both particle distributions: the fine particles provide wear resistance while the elongated particles maintain ductility through their orientation that facilitates plastic deformation.
3Ease of manufacture
If conventional powder metallurgy sintering method is used, then processing is relatively simple, but reinforced particles cluster and cannot be dispersively distributed
Solution Approach 1:
The patent applies preliminary action by pre-forming composite powder with controlled particle distribution through chemical co-precipitation and high-energy ball milling before sintering. This preliminary preparation ensures that the oxide particles are uniformly dispersed and properly sized before the sintering process, preventing clustering during subsequent processing steps.
Solution Approach 2:
The patent uses high-energy ball milling, which involves intense mechanical vibration and impact, to disperse oxide particles uniformly throughout the Ag matrix. The mechanical energy from ball milling breaks up particle clusters and ensures homogeneous distribution, which is then maintained during the subsequent hot extrusion process.
4Strength
If small nanoscale oxide particles are dispersively distributed, then contact area between particles and Ag matrix is increased, but electrical resistance is greatly increased affecting product performance
Solution Approach 1:
The patent applies segmentation by dividing the oxide particle population into two distinct size and shape categories: fine particles for wear resistance and elongated particles for conductivity. This segmentation allows each particle type to fulfill its specific function without the negative effects of the other, resolving the contradiction between mechanical strength and electrical conductivity.
Solution Approach 2:
The patent applies local quality by creating two distinct particle distribution zones: dispersed fine particles for arc ablation resistance and directionally arranged elongated particles for electrical conductivity. The directional arrangement along the extrusion direction ensures electron transport pathways are maintained, while the dispersed fine particles provide local protection against arc erosion without causing excessive electron scattering.
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
This method significantly improves arc ablation resistance by 10-20%, electrical conductivity by 5-15%, resistance to welding by 10-20%, and durability by 10-30%, while simplifying the production process and improving material processability.
Implementation Method 1
preparing precipitate of Ag + and oxide particles by chemical co-precipitation method
Implementation Method 2
granulating the composite powders by high energy ball milling
Implementation Method 3
mixing the granulated powders and Ag matrix, and processing the mixed powder by hot extrusion
Implementation Method 4
processing the mixed powder by hot extrusion
Data Source
AI summary
In the present invention, a method of preparing Ag-based oxide contact materials with directionally arranged reinforcing particles is disclosed, comprising steps of: a) preparing evenly dispersed composite powders by chemical co-precipitation method combining with roasting, b) granulating the composite powders by high energy ball milling, and sieving the powders, c) mixing the powders and Ag matrix in a powder mixing machine, d) cold isostatic pressing, e) sintering, f) hot-pressing, g) hot-extruding to obtain Ag-based oxide contact materials with directionally arranged reinforcing particles. This method can obtain particle reinforced Ag-based material with good electrical performance even when the reinforced (oxide) particles are very small. This method is simple, easy to operate, and does not require special equipment. The resistance to welding and arc erosion, electric conductivity and the processability of the material prepared through this present invention can be greatly improved.