Solid state amorphization in Ni-Ti systems: The effect of structure on the kinetics of interface and grain-boundary amorphization

Journal Article · Fri Sep 18 04:00:00 EDT 1998 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(98)00191-8· OSTI ID:665203

Benedictus, R; Han, K; Traeholt, C; Boettger, A ^[1]; Mittemeljer, E J ^[1]

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1. Delft Univ. of Technology (Netherlands). Lab. of Materials Science

Application of a thermodynamic model for solid state amorphization that incorporates differences in both bulk and interface energies for the phases concerned, shows that the microstructure of the system can largely influence the solid state amorphization behavior. For a crystalline Ni-crystalline Ti system the model predicts that amorphization can occur both along the Ni-Ti interface and along (high-angle) grain boundaries in the Ti sublayers. On the other hand for an amorphous Ni-crystalline Ti system amorphization can occur primarily along (high-angle) grain boundaries in the Ti sublayers. The model also implies the occurrence of maximum thicknesses for the amorphous product layers. Experimental data for Ni-Ti multilayers (498--548 K) support the model. Kinetic analysis suggests diffusion controlled growth of the amorphous phase. The activation energies for diffusion in the amorphous phase are found to be 126 {+-} 7 kJ/mol at the interface and 72 {+-} 25 kJ/mol in the Ti grain boundaries.

• OSTI ID: 665203
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 15 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
AMORPHOUS STATE
DIFFUSION
GRAIN BOUNDARIES
KINETICS
NICKEL ALLOYS
PHASE STUDIES
THERMODYNAMIC MODEL
TITANIUM ALLOYS