NdFeB Magnet Manufacturing via TmGn Additive and Inert Atmosphere
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for manufacturing NdFeB rare earth permanent magnetic materials are inefficient in terms of rare earth resource utilization, leading to high oxygen content, performance degradation, and challenges in mass production due to the oxidation of fine powders and inconsistent product quality.
Innovation Solution
A method involving the use of R—Fe—Co—B-M strip casting alloy, micro-crystal HR—Fe alloy fiber, and TmGn compound micro-powder, where the TmGn compound micro-powder is added to inhibit grain growth and improve anti-oxidation, combined with vacuum strip casting, hydrogen decrepitation, jet milling, and sintering processes to enhance magnetic performance and coercivity while reducing rare earth element usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional manufacturing methods are used to produce NdFeB magnets, then production volume can be maintained, but rare earth resource utilization is inefficient and oxygen content is high
Solution Approach 1:
The patent implements inert atmosphere protection throughout the manufacturing process, including vacuum sealing during strip casting, argon atmosphere during hydrogen decrepitation, and controlled atmosphere during sintering. This prevents oxidation of the rare earth elements and fine powders, thereby reducing oxygen content in the final product while improving rare earth resource utilization efficiency.
Solution Approach 2:
The patent performs preliminary protective measures before oxidation can occur: vacuum sealing of alloy strips before powdering, pre-establishment of inert atmosphere in processing chambers, and pre-coating of fine powders with protective layers. These preliminary actions prevent oxidation throughout the manufacturing chain, reducing oxygen content while maintaining high rare earth utilization.
2Productivity
If fine powders are processed without protection, then manufacturing efficiency is maintained, but oxidation occurs leading to performance degradation
Solution Approach 1:
The patent establishes continuous inert atmosphere protection throughout the entire manufacturing process from strip casting through powdering to sintering. The vacuum sealing, argon atmosphere, and controlled environment processing create an unbroken protective sequence that prevents oxidation while maintaining manufacturing efficiency and product performance consistency.
Solution Approach 2:
The patent uses inert gases (vacuum, argon) as intermediary protective environments between the fine powders and oxygen. These intermediaries allow efficient processing to continue while physically preventing oxidation, thereby maintaining both manufacturing efficiency and product reliability.
3Reliability
If heavy rare earth elements are used extensively, then magnetic performance can be improved, but resource consumption and cost increase
Solution Approach 1:
The patent optimizes the composition parameters of the alloy, controlling the precise content of heavy rare earth elements (Dy, Tb, Ho) within specific ranges (0.1-5.0 wt% Dy, 0.1-3.0 wt% Tb, 0.1-2.0 wt% Ho). This parameter optimization achieves high magnetic performance while minimizing heavy rare earth consumption through efficient utilization.
Solution Approach 2:
The patent creates a composite grain boundary phase containing multiple elements (Dy, Tb, Ho, Er, Y) combined with oxides and intermetallic compounds. This composite structure enhances magnetic performance through synergistic effects while reducing the total amount of heavy rare earth elements needed compared to using single elements in high concentrations.
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 significantly improves the magnetic energy product, coercivity, and anti-corrosion properties of NdFeB magnets, making them suitable for mass production with reduced heavy rare earth element consumption and expanded application in electronic components and energy-related fields.
Implementation Method 1
melting an R—Fe—Co—B-M raw material under vacuum or argon protection with induction heating for forming an alloy
Implementation Method 2
sending the alloy flakes and the alloy fiber into a vacuum hydrogen decrepitation device, evacuating before injecting hydrogen for hydrogen absorption
Implementation Method 3
heating after hydrogen absorption and evacuating for dehydrogenating
Implementation Method 4
powdering with jet milling
Implementation Method 5
sending the alloy powder into a nitrogen protection sealed magnetic field pressing machine for pressing
Implementation Method 6
returning the magnetic blank to a powder feeder, opening the mould and obtaining a magnetic block; wrapping the magnetic block with a plastic or rubber bag under the nitrogen protection
Implementation Method 7
sending into a vacuum sintering furnace for sintering
Implementation Method 8
after sintering, firstly ageing at 800-950° C. and secondly ageing at 450-650° C.
Data Source
AI summary
A method for manufacturing a high-performance NdFeB rare earth permanent magnetic device which is made of an R—Fe—Co—B-M strip casting alloy, a micro-crystal HR—Fe alloy fiber, and TmGn compound micro-powder, includes steps of: manufacturing the R—Fe—Co—B-M strip casting alloy, manufacturing the micro-crystal HR—Fe alloy fiber, providing hydrogen decrepitating, pre-mixing, powdering with jet milling, post-mixing, providing magnetic field pressing, sintering and ageing, wherein after a sintered NdFeB permanent magnet is manufactured, machining and surface-treating the sintered NdFeB permanent magnet for forming a rare earth permanent device.