Microstructural Change of Polycrystalline Ba-Ferrite (BaO⋅6Fe2O3) by Hot-Extrusion Processing
Year: 1987
Type: article
Abstract: The hot-working processes such as rolling, forging, extrusion etc. are widely used for metallic materials to make their shape and improve their properties. For ceramics, these processes are seldom carried out because of the lack of their plastic property. However, it is also well known that ceramics can deform plastically at high temperature. In this study we tried to examine the possibility of the hot-extrusion process for polycrystalline Ba-ferrite (BaO⋅6Fe2O3) that is easier to deform plastically than other oxide ceramics. Polycrystalline Ba-ferrite samples capsulated in stainless steel (SUS 304) were pre-heated from 1200° to 1430°C and then extruded by pressing the stem to the bullet at a maximum pressure of 800MPa. After extrusion, the body became dense and the grains became fine and orientated. The analysis by SEM and X-ray diffraction patterns showed that the polycrystalline grains had the tendency to orient their c-plane to the pressing direction and in a concentric circle. These results are discussed in view of strain rate, applied stress and slip plane. Besides, the control of the heat-transfer from the billet to the container was very important to carry out the hot-extrusion process smoothly.
Institution: Kyoto Institute of Technology
Language: English
Subfield: Ceramics and Composites
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W3130126290