Mechanical properties of spark plasma sintering NdFeB permanent magnets

Spark Plasma Sintering technique（SPS） and conventional sintering technique had been used to prepare Nd_12.2Pr₂Dy₂FebalAl₁Nb_0.3Cu_0.2B₆ sintered permanent magnet.Impact toughness and bending strength of the alloys were investigated;Microstructure and fracture morphology of the alloys were observed by scanning electronic microscopy（SEM）.The result indicates that the impact toughness of 0.955J/m² in SPS NdFeB is better than that of 0.709J/m² in conventional sintered NdFeB,and the bending strength of 402.25 MPa in SPS NdFeB is also much better than that of 278.97 MPa in conventional sintered magnet.The microstructure of SPS NdFeB alloy is composed of fine and uniform main phase grains as well as fine and even distributed Nd-rich phase.The fracture morphology shows that some cleavage face is observed in SPS NdFeB.However,the microstructure of conventional sintered NdFeB is composed of coarse grains,and its fracture morphology shows a typical intergranular fracture.