Recovery of Life for Aging Material by Addition of Grain Boundary Strength Element

Grain boundary embrittlement and de-embrittlement observed in age hardening iron alloys were reviewed. Fe-Mn-Ni and Fe-Ni-Ti alloys show excellent hardening response during aging treatment. However these alloys all suffer grain boundary embrittlemnt and show no tensile ductility even after very short aging treatment. Precipitation of intermetallic phases, θ-MnNi in Fe-Mn-Ni alloys and η-Ni3Ti in Fe-Ni-Ti alloys, at grain or lath boundaries was suggested as the reason for the weakening of grain boundary strength. Grain boundary strength recovered when these precipitates transform to austenite after extended aging. Dislocation glide or dislocation climb did critical role in conversion of these grain boundary precipitates to austenite.

Download Full-text

Understanding solute effect on grain boundary strength based on atomic size and electronic interaction

Scientific Reports ◽

10.1038/s41598-020-74065-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Zhifeng Huang ◽

Ping Wang ◽

Fei Chen ◽

Qiang Shen ◽

Lianmeng Zhang

Keyword(s):

Grain Boundary ◽

Interfacial Strength ◽

Atomic Radius ◽

Electronic Interaction ◽

Size Mismatch ◽

Atomic Size ◽

Electronic Interactions ◽

Strength Based ◽

Grain Boundary Embrittlement ◽

Boundary Strength

Abstract Solute segregating to grain boundary can stabilize the microstructure of nanocrystalline materials, but a lot of solutes also cause embrittlement effect on interfacial strength. Therefore, uncovering the solute effect on grain boundary strength is very important for nanocrystalline alloys design. In this work, we have systematically studied the effects of various solutes on the strength of a Σ5 (310) grain boundary in Cu by first-principle calculations. The solute effects are closely related to the atomic radius of solutes and electronic interactions between solutes and Cu. The solute with a larger atomic radius is easier to segregate the grain boundary but causes more significant grain boundary embrittlement. The weak electronic interactions between the s- and p-block solutes and Cu play a very limited role in enhancing grain boundary strength. While the strong d-states electronic interactions between transition metallic solutes and Cu can counteract embrittlement caused by size mismatch and significantly improve the grain boundary strength. This work deepens our understanding of solute effects on grain boundary strength based on atomic size and electronic interactions.

Download Full-text

Effect of ion implantation on the grain boundary strength of heat treated Inconel X750

Journal of Nuclear Materials ◽

10.1016/j.jnucmat.2019.01.013 ◽

2019 ◽

Vol 516 ◽

pp. 255-263 ◽

Cited By ~ 1

Author(s):

Maisaa N. Tawfeeq ◽

Robert J. Klassen

Keyword(s):

Grain Boundary ◽

Ion Implantation ◽

Heat Treated ◽

Inconel X750 ◽

Boundary Strength

Download Full-text

Electronic and structural studies of grain boundary strength and fracture in L12 ordered alloys—I. On binary A3B alloys

Acta Metallurgica ◽

10.1016/0001-6160(85)90236-6 ◽

1985 ◽

Vol 33 (7) ◽

pp. 1247-1258 ◽

Cited By ~ 126

Author(s):

T Takasugi ◽

O Izumi

Keyword(s):

Grain Boundary ◽

Structural Studies ◽

Ordered Alloys ◽

Boundary Strength

Download Full-text

Crystallinity Dependence of Grain and Grain Boundary Strength of a Bicrystal Structure of Copper

Volume 13: Micro- and Nano-Systems Engineering and Packaging ◽

10.1115/imece2020-23757 ◽

2020 ◽

Author(s):

Ken Suzuki ◽

Yiqing Fan ◽

Yifan Luo

Keyword(s):

Thin Films ◽

Grain Boundary ◽

Grain Boundaries ◽

Defect Density ◽

Volume Ratio ◽

Md Simulations ◽

Atomic Diffusion ◽

Strength And Deformation ◽

Electroplated Copper ◽

Boundary Strength

Abstract Electroplated copper thin films often contain porous grain boundaries and the volume ratio of porous grain boundaries in the copper thin films is much larger than that in bulk copper. Thus, the lifetime of the interconnection components fabricated by electroplating is strongly dominated by the strength of grain boundaries because final fracture caused by the acceleration of atomic diffusion during electromigration (EM) occurs at grain boundaries in polycrystalline interconnections. It is important, therefore, to quantitatively evaluate the grain boundary strength of electroplated copper films for estimating the lifetime of the interconnection in order to assure the product reliability. In this study, relationship between the strength and crystallinity of electroplated copper thin films was investigated experimentally and theoretically. In order to investigate the relationship between the strength and grain boundary quality, molecular dynamics (MD) simulations were applied to analyze the deformation behavior of a bicrystal sample and its strength. The variation of the strength and deformation property were attributed to the higher defect density around grain boundaries.

Download Full-text