  Bulk composites using powder blends of Mn and Bi with equal atomic ratios are
consolidated and severely deformed by high-pressure torsion (HPT). Subsequent
annealing treatments lead to the formation of the ferromagnetic and rare-earth
free hard magnetic {\alpha}-MnBi phase. The initial phase formation is studied
by in-situ high-energy XRD annealing experiments showing a beneficial influence
of HPT-deformation on the amount of {\alpha}-MnBi. The nucleation sites are
strongly increased, thus the volumetric {\alpha}-MnBi phase content exceeds 50
vol.%. A lower HPT-pressure of 2 GPa is found to be preferred over 5 GPa to
obtain high {\alpha}-MnBi contents. Annealing is done with or without applying
an external magnetic field. Additionally, influences of the HPT-induced shear
deformation are discussed and correlated with preferred diffusion path ways
fostering the formation of anisotropic {\alpha}-MnBi phase.
