| Plastic deformation plays an important role in enhancing the textural and magnetic anisotropies of Nd-Fe-B magnets made from melt-spun ribbons. To examine the effects of hot deformation on texture, Nd-Fe-B magnets with different die-upset strains were prepared by melt-spinning, crushing of melt spun ribbons to powder, followed by hot pressing and die-upsetting processes.; Inverse pole figures, pole figures, and rocking curves were determined for magnets with different upset strain. They show that the (006) peak intensity always increased with an increase in the amount of upset strain. Systematic changes in the texture coefficient in the inverse pole figure, the average of widths of the 50% intensity contour (W{dollar}sb{lcub}50{rcub}){dollar} in pole figure and the peak intensity {dollar}rm(Isb{lcub}p{rcub}){dollar} and the full width of half maximum (FWHM) of rocking curves were observed with change in percentage of upset deformation of hot pressed Nd-Fe-B magnets. The 70% die-upset produced the strongest (006) texture. The energy product (BH){dollar}rmsb{lcub}max{rcub}{dollar} increased from 17 MGOe for 0% die-upset magnet to 46 MGOe for 70% die-upset magnet.; The deformation modeling for 50%, 60%, and 70% die upset was performed by using a software "Antares" based on the finite element method. The simulation showed that the effective strain distribution is nonuniform. With increase in percentage of die-upset, the average strain increased but the strain distribution was still nonuniform. Texture variation across the thickness correlates well with the effective strain distribution data from deformation modeling. Increase in (006) texture of the magnet with increase in percentage of die-upset correlated well with increase in the average effective strain with percentage of die-upset and the improvement in magnetic properties with percentage of die-upset.; All the results show that the strongest (006) texture, maximum in B{dollar}rmsb{lcub}r{rcub},{dollar} and maximum in (BH){dollar}rmsb{lcub}max{rcub}{dollar} can be achieved by 70% die-upset. Furthermore, the peak intensity variations along the depth show that the alignment increased with the depth from the surface and the friction between sample surface and punch determine significantly the crystallographic alignment in the sample. |
