Magnet recycling to create Nd-Fe-B magnets with improved or restored magnetic performance

• Main Authors: AFIUNY PETER, ZAKOTNIK MIHA, DUNN SCOTT, TUDOR CATALINA OANA
• Format: Patent
• Language: English
• Published: 30.06.2015
• Subjects: BASIC ELECTRIC ELEMENTS; CASTING; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; COMBINED OPERATIONS; ELECTRICITY; INDUCTANCES; MACHINE TOOLS; MAGNETS; MAKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; METAL-WORKING NOT OTHERWISE PROVIDED FOR; OTHER WORKING OF METAL; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; POWDER METALLURGY; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; THEIR RELEVANT APPARATUS; TRANSFORMERS; TRANSPORTING; UNIVERSAL MACHINE TOOLS; WORKING METALLIC POWDER

Recycled Nd-Fe-B sintered magnets. One of the recycled Nd-Fe-B sintered magnets includes a composition of WaRbAc, where waste material W comprises material from a waste Nd-Fe-B sintered magnet, rare earth material R comprises at least one of: Nd or Pr, and elemental additives A comprises at least one of: Nd, Pr, Dy, Co, Cu, or Fe, and indices a, b, and c indicate atomic percentages of the corresponding compositions or elements and the atomic percentages of the rare earth material R and the elemental additives A have values satisfying Nd[0.1-19 at. %*s(Nd), x]Pr[0.1-19 at. %*s(Pr), y]Dy[0.1-19 at. %*s(Dy), z]Co[0 at. %, d]Cu[0 at. %, e]Fe[0 at. %, f] where [m,n] means a range from minimum m and maximum n, s(t) is the atomic percent of element t in starting composition, x=18 at. %-[81,99.9] at. %*(s(Nd)+s(Pr)+s(Dy)), y=18 at. %-[81,99.9] at. %*(s(Nd)+s(Pr)+s(Dy)), z=18 at. %-[81,99.9] at. %*(s(Nd)+s(Pr)+s(Dy)), d=3 at. %-[81,99.9] at. %*s(Co), e=0.3 at. %-[81,99.9] at. %*s(Cu), and f=77 at. %-[81,99.9] at. %*(s(Fe)+s(Co)).