INVESTIGATION OF FRACTURE IN PURE ALUMINIUM AFTER ECAP BY MEANS OF SMALL PUNCH TEST

摘要: The properties of pure 99.99% aluminium after severe plastic deformation by equal channel angular pressing (ECAP) with low (1, 2) and high (4, 6, 12) number passes were investigated. constant-deflection mode the small punch test was used to compare mechanical behaviour. advantages are that smaller amount material is needed sample preparation easier. Characteristic points as yield force maximum evaluated from recorded dependence vs. deflection. A possibility their conversion into variables conventional tensile discussed. Fracture energy calculated this dependence. tests performed at both room temperature elevated temperatures up 300 °C. appearance fracture surfaces observed scanning electron microscopy. tendency for increased strength ECAPed Al in comparison virgin notable well temperatures. ECAP gave greatest however not highest (12) but 1 or 2 depending on testing temperature. Higher numbers showed stagnation slight decrease Al.