Abstract
Titanium powders were shock-compressed in capsules having four kinds of cylindrical sample cavities by the flyer plate impact technique. In this study, effects due to shape changing of sample cavities in shock-compressed titanium powders were investigated. The following four types of sample cavity were utilized: type (A); 35 mm length and 6 mm diameter, type (B); 35 mm and 12 mm, type (C); 5 mm and 12 mm and type (D); 2 mm and 12 mm. In the recovered samples shock-compressed in type (A) and type (B) capsules, there observed a conical, cylindrical and spherical region involving small spherical boids. In these areas, lamellar structures due to melting were recognized with a scanning electron microscope and unknown peaks were observed with X-ray diffraction patterns. These areas are thought to be formed by effects of oblique shock waves. On the occasion of shock-compression in capsules having long length cavity, the oblique shock waves from the side wall interact in the powder samples and may generate a high temperature region, which can not be achieved only by plane shock waves. The forms of interaction vary significantly with the shapes of sample cavities.
