Papers by Keyword: GBCD

Abstract: Copper-Nickel alloy pipes in marine engineering have been suffering severe seawater corrosion and erosion-corrosion. In this work, six kinds of Cu-Ni alloy pipes with different service lives delivered by two manufacturers were used to clarify the relationship between corrosion resistance and microstructure. The corrosion behaviors of the samples in 3.5 wt.% NaCl solution were studied by electrochemical measurements. Chemical composition, grain size distribution, crystallographic orientation, and grain boundary characterization distribution (GBCD) were investigated by energy-dispersive spectrometry (EDS), metallography and electron backscattered diffraction (EBSD) technology. There were no obvious differences in chemical composition and GBCD in contrast with size and uniformity of grains. Pipes with large grains and a broader grain size distribution had better corrosion resistance. It was also found that the accuracy of experimental data greatly depended on the quality of the sample surface in EBSD analysis. The scratches and contamination during sample preparation have a strong impact on the imaging quality and the calculation of GBCD.

Abstract: Commercial Cu-ETP drawn copper bar was both mechanically and thermally treated. Repeated cycles of cold rolling and heat treatment with altered parameters were applied on the specimens. Grain boundary character distribution (GBCD) was calculated from the orientation microscopy data. As regards the processing of the orientation data the coincidence site lattice theory was applied. The evolution of the GBCD is discussed in terms of the parameters of cold rolling and heat treatment processes.

Abstract: The effects of annealing routes (batch annealing and continuous annealing) on the development of microstructure and texture in a cold-rolled Nb-IF high strength steel sheet were studied by means of optical microscopy(OM), electron backscattered diffraction(EBSD) and ODF analysis. The results show that the finer and more homogenous recrystallization grain can be observed in the CA steel. The CA process leads to an increase in the intensity of the γ-fibers, and the very sharp and uniform γ-fibers are found in this case, which is beneficial to the deep-drawability.

Abstract: The grain boundary character distribution (GBCD) and its effect on the corrosion resistance of copper and brass (H65, H80) after solid solution and cold-rolled annealing were investigated by means of static weight loss method, scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and Electron back-scattered diffraction (EBSD).The possible mechanism of the effect of proportion of low ∑ coincidence site lattice (ΣCSL) on corrosion resistance were discussed preliminary. The results show that the proportion of low ΣCSL of the three kinds of samples after cold rolling and annealing all increase obviously compared with samples in solid solution. The proportions of low ΣCSL( such as Σ3,Σ9 and Σ27 ) of H65 brass,H80 brass and copper increase in turn in the same heat treatment conditions. In addition, it can increase the grain boundary ratio of low ΣCSL up to 67.9% by cold rolling of 6% and annealing at 650°C for 10min; The corrosion experiments show that corrosion resistances of samples after heat treatment are much better than that in solid solution. In the three samples, the corrosion resistance of copper is the best and that of H80 brass is better than that of H65 brass. Key words: copper; brass; GBCD; corrosion resistance

Abstract: In last two decades it has been extensively studied whether the grain boundary engineering can be effectively applied to controlling intergranular fracture and brittleness of different kinds of brittle materials. Grain boundary engineering has been well established. A new processing method based on magnetic field application has reached a new stage of grain boundary engineering.

Abstract: Textural changes of Cu interconnects having a different line width were investigated after annealing. Texture was measured by XRD (x-ray diffraction) at different depth of the interconnect line and on the surface of interconnects using EBSD (electron backscattered diffraction) techniques. To analyze the relationship between the stress distribution and textural evolution observed in the different samples, the stresses were calculated for the different line width at 200°C using FEM (finite element modeling) along the width and depth of the line. In this investigation, it was found that the inhomogeneity of stress distribution in Cu interconnects is an important factor necessary for understanding textural transformation during annealing. Textural evolution in damascene interconnects lines during annealing is discussed, based on the state of stress in Cu electrodeposits.