In this work, first-principles were used to analyze the feasibility that titanium plate was polished by iron nitride, iron nitride particles were prepared by nitriding iron particles with NH3 and the titanium plate surface was polished by magnetic abrasive polishing (MAP) processes. It was found that the titanium plate in use was com- posed of alpha-Ti and beta-Ti which bulk modulus and shear modulus were smaller than these of epsilon-Fe3N and gamma'-Fe4N, indicating that the titanium plate could be grinded by epsilon-Fe3N and gamma'-Fe4N. By nitriding 75, 35 and 20 pin iron particles with 0.2 Mpa NH3 at 600 degrees C for 1 h, the corresponding particles containing epsilon-Fe3N and gamma'-Fe4N were obtained, respectively, which integrated ferromagnetic phase and abrasive phase and had the ability to polish titanium plate surface in nano level in the MAP processes. (C) 2020 Elsevier B.V. All rights reserved.