各向异性粘结NdFeB磁体PTFE耐高温粘结剂的研究

Study on high-temperature PTFE binder of anisotropic bonded NdFeB magnet

研究了聚四氟乙烯(PTFE)在高温条件下的物理及化学变化以及其作为各向异性粘结NdFeB的粘结剂时不同含量对磁体的磁性能、热退磁效果、尺寸精度、力学性能的影响,同时考察了PTFE粘结Nd-FeB和环氧树脂(epoxy resin)粘结NdFeB的温度稳定性。认为PTFE由于其优异的耐高温性能,能够满足磁体热退磁对粘结剂的要求,而当PTFE含量为3%(质量分数)时磁体在保证小的尺寸变化率的基础上,可以使表面剩磁降到适于防腐处理的程度,但是其强度较低。同时,PTFE各向异性粘结NdFeB在高温条件下的不可逆损失hirr,剩磁的温度系数α和矫顽力的温度系数β都较epoxy resin粘结NdFeB的大。

The physic and chemical transition of PTFE in high temperature and the effects of content of PTFE binder on magnetic properties, result of heat demagnetization, size accuracy and mechanical property were investigated. In the mean time, the stability of PTFE bonded NdFeB and epoxy resin bonded NdFeB was studied. It was found that PTFE can meet the need of heat demagnetization for anisotropic bonded NdFeB because of its excellent anti high-temperature property. If the weight percent of PTFE is 3%, the variance ratio of size and surface residual remnant of magnets is acceptable, but the mechanical property is under improved. The irreversible magnetic loss hirr, temperature coefficient of Br （α） and temperature coefficient of Hei（β） of PTFE anisotrop- ic bonded NdFeB is bigger than that of epoxy resin anisotropic bonded NdFeB in high temperature.