Magnetic Pulse Welding of Sheet Stacks for Conductive Plate Joints
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Solution Overview
Problem
Current welding techniques for assembling thin metal sheets and thick plates, such as ultrasonic and laser welding, fail to ensure sufficient compression and can cause heating, leading to poor electrical conductivity and weld quality in stacked metallic articles, particularly in electric lithium-ion batteries.
Innovation Solution
A magnetic pulse welding process that uses a coil to generate a magnetic field, exerting pressure on the plates to sandwich and weld a stack of sheets without external heat, ensuring direct contact and minimal energy loss, allowing for the assembly of materials with different melting points like copper and aluminum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ultrasonic welding or laser welding is used to assemble thin sheets and plates, then the assembly process is quick and economical, but the sheets are not sufficiently compressed and localized heating creates holes that deteriorate weld quality and reduce electrical conductivity
Solution Approach 1:
The patent replaces thermal welding processes (ultrasonic and laser welding) with magnetic pulse welding, which uses electromagnetic forces to generate mechanical impact and compression. The magnetic field generated by the coil creates a high-speed impact that compresses the sheets and plates together, eliminating the need for external heat input and avoiding the localized heating problems that create holes and reduce electrical conductivity.
Solution Approach 2:
The patent changes the fundamental parameter of the welding process from thermal energy to electromagnetic energy. By using a magnetic field instead of heat, the process achieves both sufficient compression of thin sheets and maintains electrical conductivity, as the cold welding process avoids material melting and hole formation while still creating strong bonds between components.
2Ease of manufacture
If conventional welding techniques are used, then assembly is economical, but localized heating causes holes that deteriorate weld quality
Solution Approach 1:
The patent replaces thermal welding processes with magnetic pulse welding, which uses electromagnetic forces to generate mechanical impact and compression. The magnetic field generated by the coil creates a high-speed impact that compresses the sheets and plates together, eliminating the need for external heat input and avoiding the localized heating problems that create holes and reduce electrical conductivity.
Solution Approach 2:
The patent converts the potentially harmful effect of high-energy input into a beneficial cold welding process. By using magnetic pulse energy instead of thermal energy, the process achieves strong welds without the harmful localized heating that creates holes and deteriorates weld quality, thus maintaining both manufacturing precision and cost-effectiveness.
3Strength
If magnetic pulse welding is used to apply pressure to weld plates, then direct contact and permanent weld are achieved, but the process must be applied to a stack of thin sheets without causing damage
Solution Approach 1:
The patent changes the fundamental parameter of the welding process from thermal energy to electromagnetic energy. By using a magnetic field instead of heat, the process achieves both sufficient compression of thin sheets and maintains electrical conductivity, as the cold welding process avoids material melting and hole formation while still creating strong bonds between components.
Solution Approach 2:
The magnetic pulse welding process uses a pulsed magnetic field applied in short, intense bursts rather than continuous exposure. This periodic action allows the thin sheets to be compressed and bonded without sustained high-stress exposure that could cause damage, while still achieving strong welds through the concentrated electromagnetic force during the pulse duration.
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 provides a strong, permanent weld with improved electrical conductivity by maintaining the sheets in position and minimizing delamination, while avoiding material fusion and energy losses, thus enabling efficient assembly of diverse metallic materials.
Implementation Method 1
The welding of the plate-stack assembly is carried out by subjecting the work area to a magnetic field from the coil
Implementation Method 2
The magnetic field from the active part of the coil exerts pressure on the plate closest to the coil at the working area
Data Source
Figure 1~4
Figure 5~7
AI summary
The invention relates to a method for the magnetic pulse soldering of an item comprising a stack of sheets consisting of a metal material. The method comprises: creating at least one hole (60) through a thickness of the stack (55); arranging two plates consisting of a metal material, called a first plate (51) and a second plate (52), either side of the stack, forming a covering area (53) covering the at least one through-hole (60); positioning the plates-stack assembly opposite an active part (121) of a coil (11) such that a working area of the covering area faces the active part of the coil, said working area covering the at least one hole (60); and subjecting the working area to a magnetic field until the assembly is joined. The invention is characterised in that while the working area is subjected to the magnetic field, pressure is exerted on the first plate (51), in the region of the at least one hole (60), pressing the first plate against the second plate (52).