Effect Of Soft Magnetic And The Proportion Of Iron And Cobalt On The Phase Precipitation And Magnetic Property Of SmCo/α-(Fe,Co)nanocomposite Magnets

Since the advent of nanocomposite magnets,which potential magnetic properties attracting the attention of the researchers,especially in the case of energy depleted and environmental pollution,the efficient and new environmentally friendly materials are the focus of research.Among them,SmCo/α-（Fe,Co）nanocomposite permanent magnets because of their excellent high temperature stability and get more attention to study.One of the reasons that restraint on the development of the magnet performance is the soft magnetic phase content and the composition,soft magnetic phase content is low and can not reach ideal model structure leads to the deterioration of the performance.And the coupling action between different phases is difficult to control,so that it is further limiting the performance improvement.Only by deeply understanding the transition process between different phases and the influence of phase transition on the performance,can we master the precipitation conditions of different phases and realize the artificial control to prepare high performance magnets.The commonly method in preparation of amorphous precursor is to use high energy ball milling,then processed by other technologies to get the block SmCo/α-（Fe,Co）nanocomposite permanent magnets.In this paper,we first prepare the amorphous precursor by high energy ball milling,and then have a heat treatment to the block at different temperature.Further more,we analyze the influence of the soft magnetic phase content and the proportion of iron and cobalt in soft magnetic phase on the phase transition、properties and microstructure of Sm Co/α-（Fe,Co）nanocomposite permanent magnets via X-ray diffraction（XRD）and vibrating sanple magnetometer（VSM）.We studied by XRD spectrum that increase the content of soft magnetic phase and the proportion of Fe atoms in soft magnetic phase will improve the degree of crystallization.but also promote the SmCo₃ phase crystallization.Annealing process,with the increase of temperature,phase transition process as follows: amorphous phase crystallize to Sm Co₇,amorphous phase crystallize to SmCo₃,as the annealing temperature increases,Sm Co₃ transform to SmCo₇..The samples with different soft magnetic phase content have different properties,among them,we get the maximum magnetic energy product is 9.80 MGOe when annealing temperature is 500 ℃ and the soft magnetic phase content is 10 vol.%.For the samples with different iron and cobalt ratio,the maximum magnetic energy product is 9.44 MGOe when annealing temperature is 580 ℃ and the soft magnetic components is Fe₆₅Co₃₅.