NdFeB烧结过程中可能发生的有害反应

分析并讨论了利用粉末冶金工艺在NdFeB永磁体的烧结过程中容易发生的破坏性反应,包括化学类的氧化反应、合成氨反应以及物理类的粉化反应等.其中,氧化反应最常见,且最容易发生,直接或间接地导致了其它反应的发生.提出了减少和避免这些破坏性反应发生的有效措施,即在烧结过程中保持高的真空度,制粉和成型时应添加适当的抗氧化剂,等静压时应尽量避免生坯沾上油污,生坯产品不应在空气中吸收过多的水份等.

Harmful Reactions During the Sintering of NdFeB Magnet

Some harmful reactions may occur during the sintering of NdFeB magnets,including chemical reaction of composing of ammonia and oxidation,and physical reaction of powdering,etc. Of these reactions,oxidation is easy and thus frequently to occur,which almost results in the other reactions directly or indirectly. Furthermore,some effective measures to avoid these reactions are pointed out,such as maintaining high vacuum during the sintering,adding proper oxidationproof reagent during the milling and moldings,avoiding the oil contamination and water adsorption of the green compacts.