An introduction to the BFS method and its use to model binary NiAl alloys
We introduce the Bozzolo–Ferrante–Smith (BFS) method for alloys as a computationally efficient tool for aiding in the process of alloy design. An intuitive description of the BFS method is provided, followed by a formal discussion of its implementation. The method is applied to the study of the defect structure of NiAl binary alloys. The groundwork is laid for a detailed progression to higher order NiAl-based alloys linking theoretical calculations and computer simulations based on the BFS method and experimental work validating each step of the alloy design process.
Evaluation of isomorphous models of alloys
Order-N methods for calculating the electronic structure of clusters containing hundreds of atoms using realistic self-consistent density-functional theory local-density approximation potentials make it possible to test alloy theories more definitively. Tests are carried out on isomorphous models of alloys in which the atoms of each species are treated as identical. In contrast, the order-N calculations lead to a polymorphous model in which all of the atoms are unique. Isomorphous models are seen to reproduce average densities of states and cohesive energies surprisingly well, in spite of their deficiencies in other areas. {copyright} {ital 1998} {ital The American Physical Society}
Microstructure of the solder-casting zone in bridges of dental gold alloys.
The composition and structure were studied in the cast and in the solder of bridges which had failed clinically. Both materials were gold alloys but with different contents of Pt, Ag and Zn. The metallographic investigation revealed defects mostly in the solder, situated in the subsurface layer. SEM studied of the fracture surface revealed large porosites and a structure of dense parallel lines--striations--, indicating that the material had failed from fatigue. The materials in the fractured bridges were identified by micro-probe measurements. It was stated that cast material and solder material used together, were of different composition.