Pulse Plated Copper Coating for Hydrogen Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rare earth metal-based permanent magnets lack sufficient hydrogen resistance, especially under high hydrogen gas pressure environments, leading to potential brittleness and disruption due to hydrogen absorption and reaction, and existing coating methods are either insufficient or costly.
Innovation Solution
A method involving pulse plating to form a metal coating film, preferably a Cu coating film, using specific plating solutions and conditions to achieve excellent hydrogen shielding properties, including a multilayered structure with preferred crystal orientations and anticorrosive coatings to enhance hydrogen resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a multilayered metal coating film with 4 or more layers is formed to improve hydrogen resistance, then hydrogen shielding property is enhanced, but device complexity and manufacturing cost increase
Solution Approach 1:
The invention extracts and isolates the critical function of hydrogen shielding to a single metal coating layer, removing the need for complex multilayered structures. By identifying that one properly designed metal coating layer is sufficient for hydrogen resistance, the patent simplifies the coating system from multiple layers to a single functional layer.
Solution Approach 2:
The invention changes the parameters of the metal coating layer, specifically setting the thickness to 3 μm or more but 20 μm or less, and specifying copper content at 50 mass% or more. These parameter changes optimize the coating for hydrogen resistance while maintaining simplicity and cost-effectiveness.
2Reliability
If a thick metal coating film is formed to improve hydrogen resistance, then hydrogen shielding property is enhanced, but the effective volume of the magnet is reduced
Solution Approach 1:
The invention optimizes the thickness parameter of the metal coating layer to be 3 μm or more but 20 μm or less. This parameter range provides sufficient hydrogen shielding while minimizing the reduction in effective magnet volume, achieving a balance between protection and volume preservation.
3Reliability
If conventional continuous plating is used to form a metal coating film, then the process is simple, but the coating film lacks sufficient hydrogen shielding property under high pressure
Solution Approach 1:
The invention employs periodic pulse plating instead of continuous plating to form the metal coating layer. The pulse plating process uses periodic on-off cycles of current application, which creates a coating with superior hydrogen shielding properties while maintaining manufacturing feasibility.
Solution Approach 2:
The invention changes the plating process parameters by specifying pulse plating conditions with a duty cycle of 1% to 90%, peak current density of 0.1 to 50 A/dm², and pulse frequency of 0.1 to 1000 Hz. These parameter changes produce a coating structure that provides excellent hydrogen resistance.
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 provides a simple, low-cost solution for imparting excellent hydrogen resistance to rare earth metal-based permanent magnets, preventing disruption and maintaining magnet integrity under high hydrogen gas pressure, as demonstrated by extended durability in pressurized hydrogen tests.
Implementation Method 1
forming a metal coating film by pulse plating on the surface of the article
Implementation Method 2
forming a metal coating film by pulse plating on the surface of the article
Implementation Method 3
the metal coating film formed by pulse plating exhibits excellent hydrogen shielding property
Data Source
AI summary
A simple and low cost method for imparting excellent hydrogen resistance to various types of articles such as a rare earth metal-based permanent magnet. A method for imparting hydrogen resistance to an article of the present invention is characterized by forming a metal coating film by pulse plating on the surface of the article.