Influence of grain boundary characteristics on thermal stability in nanotwinned copper

Influence of grain boundary characteristics on thermal stability in nanotwinned copper

High density grain boundaries provide high strength, but may introduce undesirable features, such as high Fermi levels and instability. We investigated the kinetics of recovery and recrystallization of Cu that was manufactured to include both nanotwins (NT) and high-angle columnar boundaries. We used the isothermal Johnson-Mehl-Avrami-Kolmogorov (JMAK) model to estimate activation energy values...

Fracture toughness and fatigue crack growth characteristics of nanotwinned copper

Recent studies have shown that nanotwinned copper (NT Cu) exhibits a combination of high strength and moderate ductility. However, most engineering and structural applications would also require materials to have superior fracture toughness and prolonged subcritical fatigue crack growth life. The current study investigates the effect of twin density on the crack initiation toughness and stable ...

Measuring the Influence of Grain-Boundary Misorientation on Thermal Groove Geometry in Ceramic Polycrystals

We have used electron backscattered diffraction patterns to determine the misorientation of 201 adjacent pairs of grains in a magnesia polycrystal. The width and depth of the thermal grooves formed by these same grain boundaries were also measured by atomic force microscopy (AFM). By simulating the errors associated with the AFM observations and comparing our observations to existing data for m...

Five-parameter grain boundary distribution of commercially grain boundary engineered nickel and copper

The five-parameter grain boundary distributions of grain boundary engineered nickel and copper specimens have been analyzed in detail. The relative areas of {111} planes in the entire population did not increase as a result of grain boundary engineering (GBE) and, in the R3-excluded population, decreased after GBE. This decrease occurred because the majority of the newly generated R3 grain boun...

Effect of Grain Boundary Engineering on Microstructural Stability During Annealing