几种常见介质对NdFeB磁体的腐蚀研究

Research on the erosion of several familiar medium to NdFeB magnets

采用失重法,分别在空气、自来水、氯化钠溶液、硫酸溶液及氢氧化钠溶液等几种常见介质中,对NdFeB磁体不同温度下的腐蚀情况进行了研究。结果表明:在同种介质中,NdFeB磁体的腐蚀速率随温度的升高而加快;pH值较小时,腐蚀严重;而当溶液的pH值增加时,样品的腐蚀速率减缓;当pH>10时,样品的质量基本不减少;pH>12,θ>25℃时,样品表面会形成碱式化合物,总质量增加,样品几乎不再受到腐蚀。

The erosions of NdFeB magnets in several familiar mediums, （air, tap water, NaCI solution, H2SO4 solution and NaOH solution）, at different temperatures were researched by weightless method. The results show that the eroding speed rate of NdFeB magnets increases with increase of temperature in same medium. If pH value is low, the erosion is serious; the eroding speed rate of sample reduces when pH value of solution is increased; the samples＇ mass doesn＇t decrease when pH value is above 10; when pH value is above 12 and the temperature is above 25℃, basic compounds are formed on the surface of NdFeB samples, total mass increases, the sample is almost not eroded.