Production of a highly porous material by liquid phase sintering of short ferritic stainless steel fibres and a preliminary study of its mechanical behaviour

A procedure is outlined for the production of highly porous material by liquid phase sintering of short stainless steel fibres, about 100 (mu)m in diameter. The fibres, which were produced by a melt extraction route, were first electroplated with copper to a thickness of a few (mu)m. The sintering procedure was then completed by holding at about 1100 °C for a few minutes. It is shown that this operation generates strong joints by the migration of liquid copper to the fibre–fibre contact regions, as a result of capillary action. A preliminary study of the mechanical behaviour material produced in this way indicates that its toughness is relatively high, for a highly porous metallic material, and that its fracture energy is broadly consistent with predictions from a model based on evaluation of the work done by plastic deformation and rupture of individual fibres close to the fracture plane.