한국주조공학회

In-situ quasicrystalline icosahedral (I) phase reinforced Ti-based bulk metallic glass (BMG) matrix composites have been successfully fabricated by using two distinct thermal histories for BMG forming alloy. The BMG composite containing micron-scale Iphase has been introduced by controlling cooling rate during solidification, whereas nano-scale I-phase reinforced BMG composite has been produced by partial crystallization of BMG. For mechanical properties, micron-scale I-phase distributed BMG composite exhibited lower strength and plasticity compared to the monolithic BMG. On the other hand, nano-scale icosahedral phase embedded BMG composite showed enhanced strength and plasticity. These improved mechanical properties were attributed to the multiplication of shear bands and blocking of the shear band propagation in terms of isolation and homogeneous distribution of nanosize icosahdral phases in the glassy matrix, followed by stabilizing the mechanical and deformation instabilities.

Icosahedral phase, Bulk metallic glass matrix composite, Strength, Plasticity, Shear band, Crystallization.