Hot-dip Aluminizing Technique for Sintered NdFeB Permanent Magnet

The advantages and disadvantages of present techniques for improving the oxidation resistance of NdFeB permanent magnet were analyzed.A hot-dip aluminizing technique for NdFeB permanent magnet was put forward.The structure and composition of the coating and the cohesion between the coating and the matrix were investigated.The results indicate that superior metallurgical cohesion can be obtained between the aluminum coating and the NdFeB matrix,so the cohesion strength can essentially improved.In addition,the oxidation resistance of the hot-dip aluminized NdFeB was also studied.It is found that the inactivation and anodic protection of the aluminum coating can realize double protection for the NdFeB permanent magnet matrix.