The solution to this situation is to control the composition of the grain boundary phase and control the morphology of the grain boundary phase.
1. Control the composition of the grain boundary phase: By precisely controlling the composition of the grain boundary phase, its distribution and stability in the material can be affected. For example, in NdFeB permanent magnet materials, the magnetic properties can be improved by introducing specific elements (such as copper) into the grain boundaries.
2. Control the morphology of the grain boundary phase: By controlling the morphology of the grain boundary phase, the interface characteristics with the main phase grains can be affected. For example, by controlling the heat treatment process, grain boundary phases of different shapes and sizes can be obtained.