Functionally Graded Electrical Contacts via Cold Spray Deposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing processes for manufacturing electrical contacts, such as metal powder sintering, are time-consuming and inefficient, requiring multiple vacuum sintering runs and extensive machining, and do not allow for economical gradient compositions.
Innovation Solution
A method involving cold spray additive manufacturing, where solid state metals are deposited onto a substrate using compressed gas to form a bond below their melting temperature, allowing for the creation of functionally graded multi-material electrical contacts with varying metal compositions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal powder sintering process is used to produce electrical contacts, then the contacts achieve sufficient density and metallurgical bonds, but the production time increases to six to ten days
Solution Approach 1:
The invention changes the fundamental parameters of the manufacturing process by replacing thermal sintering with cold spray deposition. This involves changing the temperature parameter from high-temperature sintering to room temperature or near-room temperature deposition, and changing the bonding mechanism from diffusion-based metallurgical bonds to deformation-based solid state bonds through high-velocity particle impact
Solution Approach 2:
The invention replaces the thermal field-based sintering process with a mechanical field-based cold spray process. Instead of using heat to create metallurgical bonds, the process uses high-velocity gas jet to accelerate metal particles that deform and bond mechanically upon impact with the substrate, eliminating the need for extended thermal processing time
2Manufacturing precision
If three vacuum sintering runs are performed to achieve high quality sintered powder disk, then the porosity is reduced and quality is improved, but the production time and process complexity increase
Solution Approach 1:
The invention segments the manufacturing process into additive layers rather than requiring multiple complete sintering cycles. Each layer of metal powder is deposited and bonded independently through cold spray, allowing progressive building of the contact with controlled porosity at each stage, eliminating the need for repeated vacuum sintering runs
Solution Approach 2:
The invention performs preliminary bonding action during the deposition process itself. The cold spray process creates solid state bonds between particles as they are deposited, pre-consolidating the structure before final machining. This preliminary consolidation reduces porosity incrementally with each layer without requiring subsequent vacuum sintering cycles
3Manufacturing precision
If extensive machining is performed on sintered contacts to meet configuration requirements, then the dimensional precision is improved, but the production time and material waste increase
Solution Approach 1:
The invention inverts the traditional manufacturing sequence by using additive manufacturing to build the contact geometry directly rather than removing material through machining. The cold spray process deposits metal in the final or near-final configuration, eliminating or minimizing the need for subsequent machining operations to achieve dimensional precision
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 method significantly reduces production time to 2-25 minutes, offers cost-effective and flexible design options, and enhances properties like arc erosion resistance and conductivity by varying metal compositions within the contact.
Implementation Method 1
depositing the first metal and second metal on a substrate by applying a compressed gas to the metals to eject the metals toward the substrate, wherein the depositing is performed under a pressure sufficient to form a solid state bond between the first and second metals to yield a material column, while maintaining the material column at a temperature that is below the melting temperature of both the first and second metals
Implementation Method 2
applying a compressed gas to the metals to eject the metals toward the substrate, wherein the depositing is performed under a pressure sufficient to form a solid state bond between the first and second metals
Implementation Method 3
operating a material feeder on a friction stir additive device to release a feed of a first solid state metal and a second solid state metal onto a substrate, yielding a material column, wherein the material feeder includes a receiver defined by a rotatable shoulder, and wherein operating the material feeder on the friction stir additive device to release the feed of the first and second metals onto a substrate includes: applying pressure to the first and second metals in the receiver, and rotating the material feeder shoulder around the first and second metals, to form a solid state bond between the released metals
Data Source
AI summary
The presently disclosed subject matter relates to multi-material electrical contacts, and methods of making multi-material electrical contact comprising a functionally graded monolithic structure, having a first metal and a second metal, an amount of the second metal as compared to an amount of the first metal increases with distance in the structure from a first surface to a second opposing surface of the structure such that the second metal content increases continuously or incrementally throughout the height of the electrical contact.