NdFeB铸块在HD工艺中的吸氢行为研究

Research on Hydrogen-Absorbing Behaviour of NdFeB Ingot in HD Process

采用真空感应炉熔炼合金 ,用不锈钢压力罐充入H2 进行HD实验 ,对NdFeB铸块在HD工艺中的吸氢行为进行了研究。研究发现 ,Nd FeB铸块在氢爆过程中明显存在孕育期 ,其吸氢过程分为 3个阶段 :慢速吸氢阶段、快速吸氢阶段和缓慢吸氢阶段 ;随氢气压力 (1～ 4× 10 5Pa)的升高 ,孕育时间缩短 ,吸氢更快 ,当压力达到了 2～ 3× 10 5Pa时 ,获得较好的HD效果 ;随铸块粒度的减小 ,孕育时间缩短 ,吸氢越彻底。研究同时发现 ,随温度的升高 ,NdFeB铸块吸氢越迅速 ,当温度升至一定程度时 ,孕育期消失 ,3 5 3K时吸氢效果最佳。

Alloy was melted in vacuum induction furnace and HD process was carried out in stainless steel container filled with needed hydrogen. Research was done on hydrogen-absorbing behaviour of NdFeB in HD process. It is found that incubation period obviously exists, and that there exist three stages in the process of absorbing hydrogen: slow absorption, rapid absorption and extremely slow absorption. With the increase of hydrogen pressures(from 1×105 Pa to 4×105 Pa), the incubation period is shorter and the rate of absorbing hydrogen is quicker. When the pressure goes up to 2～3×105 Pa, HD is carried out well. With the decrease of the ingot granularity, the incubation period is shorter and more hydrogen is absorbed. Meanwhile, it is found that the rate of absorbing hydrogen is quicker when the temperature rises. The incubation period disappears when the temperature rises to a certain value. Hydrogen is absorbed best when the temperature is 353 K.