Controlling the length scale and distribution of the ductile phase in metallic glass composites through friction stir processing.
Sci Technol Adv Mater
; 15(3): 035011, 2014 Jun.
Article
em En
| MEDLINE
| ID: mdl-27877687
ABSTRACT
We demonstrate the refinement and uniform distribution of the crystalline dendritic phase by friction stir processing (FSP) of titanium based in situ ductile-phase reinforced metallic glass composite. The average size of the dendrites was reduced by almost a factor of five (from 24 µm to 5 µm) for the highest tool rotational speed of 900 rpm. The large inter-connected dendrites become more fragmented with increased circularity after processing. The changes in thermal characteristics were measured by differential scanning calorimetry. The reduction in crystallization enthalpy after processing suggests partial devitrification due to the high strain plastic deformation. FSP resulted in increased hardness and modulus for both the amorphous matrix and the crystalline phase. This is explained by interaction of shear bands in amorphous matrix with the strain-hardened dendritic phase. Our approach offers a new strategy for microstructural design in metallic glass composites.
Texto completo:
1
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article