An experimental investigation

The metallurgy of zinc-coated steel

Self-propagating exothermic reactions: the synthesis of high-temperature materials by combustion

Effect of boron on grain-boundaries in Ni3Al†

Alloy design based on single-principal-element systems has approached its limit for performance enhancements. A substantial increase in strength up to gigapascal levels typically causes the premature failure of materials with reduced ductility. Here, we report a strategy to break this trade-off by controllably introducing high-density ductile multicomponent intermetallic nanoparticles (MCINPs) in complex alloy systems. Distinct from the intermetallic-induced embrittlement under conventional wisdom, such MCINP-strengthened alloys exhibit superior strengths of 1.5 gigapascals and ductility as high as 50% in tension at ambient temperature. The plastic instability, a major concern for high-strength materials, can be completely eliminated by generating a distinctive multistage work-hardening behavior, resulting from pronounced dislocation activities and deformation-induced microbands. This MCINP strategy offers a paradigm to develop next-generation materials for structural applications.

Multicomponent intermetallic nanoparticles and superb mechanical behaviors of complex alloys

Dynamic embrittlement of boron-doped Ni3Al alloys at 600°C☆

Surface and grain boundary segregation in relation to intergranular fracture: Boron and sulfur in Ni3Al

Expressions for the major variables in the general rate equation for solid-solid nucleation were developed on the basis of various models of the critical nucleus shape during homogeneous and heterogeneous nucleation. These models are based upon spheres, but in some a facet was incorporated at one boundary orientation to represent the presence of a partially or fully coherent structure. Gibbs’ relationship for the critical radius is applicable to all of the models. The other variables in the nucleation rate equation are affected by the model and by faceting. Reduction of AG* by faceting is concluded to be the primary cause for the presence of reproducible lattice orientation relationships and for the existence of transition phases during precipitation from solid solutions.

Influence of crystallography on aspects of solid-solid nucleation theory

The segregation of S to grain boundaries in Ni3Al and Ni3(Al, Ti) has been studied using Auger electron spectroscopy. The S concentration at the grain boundaries decreases more slowly with increasing temperature than would be predicted by segregation models based on a single solute binding energy to the grain boundaries. This behavior, which can be interpreted as an increase in the effective solute binding energy for a grain boundary as a function of temperature, is consistent with predictions of a model based on the existence of a spectrum of solute binding energies for grain boundaries.

Calvin L. White

Papers

Effect of boron on grain-boundaries in Ni3Al†

Dynamic embrittlement of boron-doped Ni3Al alloys at 600°C☆

Surface and grain boundary segregation in relation to intergranular fracture: Boron and sulfur in Ni3Al

Influence of crystallography on aspects of solid-solid nucleation theory

Sulfur segregation to grain boundaries in Ni 3 Al and Ni 3 (AI,Ti) alloys