抄録
A novel evaluation method of the crystallinity of grain boundaries was proposed by analyzing the quality of Kikuchi lines obtained from the conventional EBSD analysis. This method can evaluate the porous and brittle grain boundaries by IQ (Image Quality) and CI (Confidence Index) .Both IQ and CI values are the parameters which are calculated from the observed result of the Kikuchi pattern obtained from the area where electron beams penetrate during EBSD analysis. The IQ value indicates the crystallinity of the measured area. It is average intensity of Kikuchi lines obtained from the measured area during EBSP analysis. The CI value indicates the reliability of the determined orientation of the measured area. When a grain boundary crosses a measured area, there are two grains with different crystallographic direction. In this case, there should be two different Kikuchi patterns in the measured area. Thus, the CI value ranges from 0 to 1. When the crystallinity of the two grains are close, this CI value becomes almost 0. On the other hand, the CI value is 1, when the measured are consists of one grain. Low CI value is also observed in the area which consists of plural grain boundaries, nanocrystal and amorphous. It was found that the local areas with low IQ value and low CI value correspond to porous grain boundaries. Therefore, the quality of grain boundaries can be evaluated by using the proposed combination of the IQ and CI values clearly, and thus, this method is effective for predicting the fracture mode of the electroplated copper thin films under a fatigue load.
