Silver-Graphite Contact Material Sintering Process
Solution Overview
Problem
Existing methods for preparing silver-graphite electrical contact materials face challenges such as weak interface bonding, low yield, and uneven solder layer thickness, particularly in the production of continuous strips, due to issues with decarburization and extrusion processes.
Innovation Solution
A method involving hot extrusion of silver-graphite ingots into sheet materials with a U-shaped structure, followed by sintering with a solder strip, and subsequent rolling and heat treatment to achieve a uniform and dense composite with improved bonding and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If decarburization technique is used to remove graphite on the surface of silver-graphite materials, then a pure silver layer is formed, but the process requires precise control parameters, large energy consumption, and is time-consuming
Solution Approach 1:
The invention changes the fundamental process parameters from decarburization (high temperature, long time, precise control) to direct sintering of silver powder coating (lower temperature, shorter time, simpler control), achieving the same pure silver layer formation without the adverse effects
Solution Approach 2:
The invention extracts and eliminates the decarburization step entirely, directly forming the pure silver layer through sintering of silver powder, thereby removing the time-consuming and energy-intensive process while maintaining the desired layer quality
2Manufacturing precision
If decarburization technique is used, then a pure silver layer is formed, but it is not suitable for continuous strip of silver-graphite electrical contact materials
Solution Approach 1:
The invention changes the process parameters and method from decarburization to direct sintering with silver powder coating, making the process adaptable to continuous strip materials while maintaining welding layer quality
Solution Approach 2:
The sintering process with silver powder coating serves multiple functions: it forms the pure silver layer, ensures welding quality, and is applicable to both granular and continuous strip materials, enhancing the versatility of the manufacturing process
3Manufacturing precision
If silver layer is coated on silver-graphite ingot and extrusion is performed, then composite silver layer is formed, but interface bonding is weak with many unbonded regions and holes
Solution Approach 1:
The invention applies preliminary action by coating silver powder on the silver-graphite material before sintering, ensuring proper adhesion and bonding at the interface, thereby preventing unbonded regions and holes that occur with post-coating methods
Solution Approach 2:
The invention replaces the mechanical extrusion process with a thermal sintering process, using heat and pressure to achieve dense bonding at the interface, eliminating the unbonded regions and holes caused by mechanical extrusion
4Productivity
If extrusion is performed on coated ingot, then silver-graphite strip material is obtained, but outer coating layer peels and falls off, resulting in low yield
Solution Approach 1:
The invention performs preliminary silver powder coating followed by sintering to ensure strong adhesion before any forming operations, preventing peeling and falling off during subsequent processing, thereby improving yield
Solution Approach 2:
The invention replaces mechanical extrusion with thermal sintering, achieving strong bonding between the silver layer and substrate that prevents peeling during handling and processing, thus improving production efficiency and yield
5Manufacturing precision
If silver-graphite ingot is coated with silver layer and extruded, then strip material with pure silver layer is obtained, but utilization rate of coating layer is low due to waste material formation
Solution Approach 1:
The invention applies preliminary silver powder coating and sintering to form a bonded pure silver layer that remains attached to the substrate, eliminating the waste material formation associated with extrusion and significantly improving silver utilization rate
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 approach results in a high-yield, continuous silver-graphite electrical contact material with a uniformly controllable solder layer, enhancing interface bonding quality and production efficiency while simplifying the process and reducing costs.
Implementation Method 1
performing a sintering to composite a solder strip material with the silver-graphite electrical contact sheet material to obtain a composite blank
Implementation Method 2
performing a rolling and a heat treatment on the composite blank for one or more times to complete the composite
Data Source
Figure 1~3
Figure 4
AI summary
The present invention provides a preparation method of a rapid bonding of a long silver-graphite electrical contact material and a solder strip material, including the following steps: first step, making a silver-graphite spindle into a silver-graphite electrical contact sheet material by an extrusion process; second step, performing a sintering to composite a solder strip material with the silver-graphite electrical contact sheet material to obtain a composite blank; and third step, performing a rolling and a heat treatment on the composite blank for one or more times to complete the composite of the long silver-graphite electrical contact material and the solder strip material. According to the present invention, a highly efficient and rapid composite of the long silver-graphite electric contact sheet material and the solder strip material is realized, products with good interface bonding quality and high dimensional accuracy are produced, and continuity and short process can be realized, which facilitates the realization of soldering automation. The method of the present invention is a novel method for preparing a silver-based electrical contact material and solder composite material.