The microstructures and strength of pure Ni ball after high speed collision process were investigated. The elongated and equiaxed nanocrystallines with high angle grain boundaries and random grain orientation were formed near the interface position due to high strain and strain rate. Sufficient intragranular recrystallization occurred due to shock induced storage energy. Sufficient recrystallization in the grain interior facilitated to activate dislocation in the process of subsequent deformation and resulted in ameliorated hardness. Moreover, the high angle grain boundaries could effectively impede the dislocation movement, which also significantly enhanced the strength of Ni ball near the interface.
|Number of pages||5|
|Journal||Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing|
|Publication status||Published - 2018 Oct 24|
- High angle boundaries
- High speed collision