Metal Induced Embrittlement and The Role of Defect Structures in Grain Boundaries on the Deformation and Fracture Behavior of Crystalline Solids (Grant DE-FG06-87ER45287 Summary Accomplishments)
- Washington State Univ., Pullman, WA (United States)
Grant DE-FG06-87ER45287 was active during the period from June 1987 through May, 1998 at which time the grant identification was changed. During the period for which Grant DE-FG06-87ER45287 was active the research program was initially titled “Metal Induced Embrittlement”. A somewhat different research topic was pursued under the same grant identifier but with the title “The Role of Defect Structures in Grain Boundaries on the Deformation and Fracture Behavior of Crystalline Solids” which began upon renewal of the program June 1, 1995 and continued until a second renewal occurred on June 1, 1998 under the new grant designation DE-FG03-98ER45697. Therefore this report is intended to provide a recapitulation of the achievements during the active period of Grant DE-FG06-ER45287. The principal achievements of this work are represented by the papers published fi refereed literature, the presentations at national and international symposia and the degrees granted to students that were supported by this grant. These items are included in separate sections below. The following list highlights some of the most notable findings that derive from the research supported under Grant DE-FG06-ER45287. Measurements of the K-dependence of the crack growth rates in aluminum alloys in contact with liquid Hg and Ga. Experimental determination “of the effect of strength level of aluminum alloys on the K-da/dt embrittlement response. Explanation of the plastic wake effect on liquid metal embrittlement (LME) phenomena. Measurement and explanation of the effect of oxygen on LME of aluminum alloys. Measurement of the temperature dependence and the activation energy for grain boundary penetration of Ga in aluminum. Development and implementation of techniques for performing in-situ observation and characterization of Ga penetration of grain boundaries in a TEM. Development of models explaining the driving force and kinetics for LME processes. Atomistic simulation of crack tips identifying the principal factors controlling the emission of dislocations and ductile versus brittle behavior: Atomistic studies that help to describe the effect of dissolved hydrogen on the competition between dislocation emission and fracture of fcc metals. Atomistic studies of LME. Atomic simulation of short-circuit diffusion within dislocation cores. Evaluation of the relevance of various grain boundary defects to GB fracture and sliding processes. The use of atomistic simulations to evaluate the strength of dislocation barriers. Correlation of grain boundary structure with Ga penetration velocities in general grain boundaries in aluminum. Development of a methodology to characterize grain boundary structure using Ga penetration phenomena.
- Research Organization:
- Washington State Univ., Pullman, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG06-87ER45287
- OSTI ID:
- 761733
- Country of Publication:
- United States
- Language:
- English
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