부산대학교 도서관

Cavity cloud formation and generation of stringy damage patterns on an aluminium specimen in a polymer solution were studied using a vibratory cavitation facility. It is shown that few bubbles are seen on a specimen although numerous bubbles appear at a place several millimetres away from the specimen. Since a polymer solution may behave elastically due to the relaxation effect, the solution can follow the vibration of the specimen. Therefore the pressure on the specimen in the polymer solution does not fall to as great an extent as in water, and so consequently fewer bubbles form. Stringy damage patterns originate from cracks on the specimen surface or impurities in the polymer solution adjacent to the specimen. It is also shown that the addition of polymer greatly affected the damage rate.