Light Metal Joint Filler for Low-Temperature Silver Sintering
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Solution Overview
Problem
Current joint fillers for light metals, such as brazing fillers and nano-silver pastes, face issues of high-temperature deformation and high costs, particularly due to the need for high-temperature joining processes and expensive materials.
Innovation Solution
A metal joint filler composed of micron-scale light metal powder and nanoscale or submicron-scale silver powder, mixed with a solvent, is used for low-temperature joining, where the silver powder is sintered and bonded with the light metal surfaces under controlled pressure, allowing for bonding at temperatures between 200°C and 400°C in atmospheric pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If brazing filler is used for metal joining, then joining temperature can be achieved, but metal piece deformation occurs and costs increase
Solution Approach 1:
The patent changes the temperature parameter from conventional brazing temperatures (580-600°C) to low-temperature sintering (200-400°C). This is achieved by using nanoscale silver powder as the primary bonding agent instead of traditional brazing fillers, fundamentally altering the thermal process parameters to avoid metal piece deformation while maintaining joining effectiveness
Solution Approach 2:
The joint filler is designed as a composite material containing nanoscale silver powder (2-50 wt%), micron-scale light metal powder (40-98 wt%), and organic vehicle. This composite structure combines the high-strength bonding capability of nanoscale silver with the compatibility of light metal powder, enabling low-temperature sintering that prevents deformation of the base metal pieces
2Temperature
If nano-silver paste is used for low-temperature joining, then deformation is prevented, but costs increase significantly
Solution Approach 1:
The patent applies local quality by concentrating nanoscale silver powder (10-500 nm) specifically at the joint interface where bonding is required, while using cheaper micron-scale light metal powder as the bulk filler material. This localized high-quality approach ensures strong bonding at the critical interface while reducing overall material costs compared to using pure nano-silver paste throughout
Solution Approach 2:
The patent replaces expensive pure nano-silver paste with a cost-effective composite formulation where nanoscale silver (2-50 wt%) is combined with abundant, low-cost micron-scale light metal powder. This substitution uses a small amount of expensive nanomaterial strategically where needed, mixed with plentiful inexpensive material, dramatically reducing filler costs while maintaining joining performance
3Reliability
If brazing filler is used, then joining can be performed, but process complexity and equipment costs increase
Solution Approach 1:
The patent replaces the complex brazing process (requiring vacuum equipment, protective atmospheres, and precise temperature control systems) with a simpler sintering process. The nanoscale silver powder enables bonding through diffusion and sintering mechanisms at low temperatures, eliminating the need for complex vacuum or protective atmosphere equipment while maintaining reliable joining capability
Solution Approach 2:
The patent eliminates the requirement for inert or vacuum atmospheres by using a composite filler system where nanoscale silver powder provides oxidation resistance and the organic vehicle formulation is designed to be stable in atmospheric conditions. This allows the joining process to be performed in simple atmospheric pressure environments without complex atmosphere control equipment
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 reduces material costs and prevents deformation by enabling low-temperature joining of light metals, achieving strong shear strength while lowering equipment and process costs compared to traditional methods.
Implementation Method 1
hot pressing the two to-be-joined light metal pieces, so that the silver powder is sintered and bonded with the light metal powder and surfaces of the two to-be-joined light metal pieces
Data Source
AI summary
A light metal joint filler is provided. The light metal joint filler is formed by uniformly mixing a solvent with a light metal powder and a silver powder, where a powder particle size of the light metal powder is on a micron scale, and a powder particle size of the silver powder is on a nanometer scale or a submicron scale. A metal joining method of the present disclosure includes: coating a joint of two to-be-joined light metal pieces with the light metal joint filler; and hot pressing the two to-be-joined light metal pieces, so that the silver powder is sintered and bonded with the light metal powder and surfaces of the two to-be-joined light metal pieces, and completing joining of the two to-be-joined light metal pieces after the silver powder is condensed.