Nd-Fe-B Magnet Plating via Cathode Arc Deposition
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Solution Overview
Problem
Existing methods for plating Nd—Fe—B magnets, such as multi-arc ion plating and magnetron sputtering, face limitations due to low target source material utilization rates and the need for non-magnetic target source materials, which can be costly and damage the magnetic properties of the magnets at high temperatures.
Innovation Solution
An apparatus and method where the cathode and target source holder maintain a predetermined distance of between 5 mm and 200 mm to enhance the efficiency and uniformity of metal film deposition on Nd—Fe—B magnets, using a furnace with a vacuum chamber and power sources for cleaning and vaporizing the target source material, allowing for a more efficient and environmentally friendly process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If vacuum evaporation plating method is used to deposit metal film on Nd-Fe-B magnet, then target source material utilization rate is improved, but high temperature causes magnetic materials to deteriorate and magnetic properties to reduce
Solution Approach 1:
The patent changes the fundamental parameter of the deposition process from thermal evaporation to cathode arc deposition. This parameter change allows the target material to be deposited at lower temperatures, preventing deterioration of the Nd-Fe-B magnet's magnetic properties while maintaining high target source material utilization rate through the arc discharge process that directly sputters material from the target onto the magnet surface.
2Reliability
If multi-arc ion plating or magnetron sputtering is used to deposit anti-corrosion film, then magnetic properties are preserved, but target source material utilization rate is low and costs increase
Solution Approach 1:
The patent extracts the essential benefit of arc deposition (high material utilization) while eliminating its harmful effect (high temperature damage to magnetic properties). By using cathode arc deposition where the Nd-Fe-B magnet itself serves as the cathode, the process achieves high target source material utilization through direct arc sputtering while the magnet remains cool enough to preserve its magnetic properties.
3Productivity
If target source holder is placed close to cathode for efficient deposition, then deposition efficiency is improved, but coating uniformity may be affected
Solution Approach 1:
The patent introduces dynamic movement of the target source holder relative to the cathode during the deposition process. The target source holder can move along the cathode surface, allowing the arc discharge to traverse different areas and deposit material uniformly across the entire cathode surface, thereby achieving both high deposition efficiency and uniform coating thickness.
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 uniform metal film with reduced damage to the magnets, lower target source material limitations, and a more controlled plating process at lower temperatures, improving the overall efficiency and environmental sustainability of the plating process.
Implementation Method 1
a power source electrically connected to the cathode and the anode for cleaning and vaporizing the target source material
Implementation Method 2
a power source electrically connected to the cathode and the anode for cleaning and vaporizing the target source material
Implementation Method 3
the target source material of metal is deposited on the purified Nd—Fe—B magnet to produce a coated Nd—Fe—B magnet
Data Source
AI summary
An apparatus for plating Nd—Fe—B magnet includes a cathode and a target source holder defining a predetermined distance of 5 mm to 200 mm therebetween. A pulse bias power supply having a first positive terminal connected to an anode and a first negative terminal connected to the cathode. A DC bias power supply having a second positive terminal connected to the anode and a second negative terminal connected to the target source holder. The anode is connected to the earth ground. A method for plating the Nd—Fe—B magnet includes steps of maintaining the predetermined distance of 5 mm to 200 mm between the cleaned Nd—Fe—B magnet and the target source material, increasing a first electric potential to the cathode and a second electric potential to the target source holder with the second electric potential greater than the first electric potential, and maintaining a potential differential of 0V to 500V therebetween.