Slipenyuk O. Effect of temperature on structure, mechanisms of deformation and mechanical properties of amorphous and nanophase materials

Dissertation is dedicated to studying the effect of nanoscale structure elements upon the peculiarities of deformation and failure mechanisms. Detailed examination of amorphous metallic alloys (AMA) microhardness dependence versus temperature has been carried out in a wide range of testing temperatures (77 to 900K). For the first time the influence of structural relaxation on the temperature dependence of AMA’s microhardness value has been noticed. Effect of alloying with such elements as B, Si, Cr, Ni, Cu, Nb on AMA’s strength and thermal stability behaviour is fulfilled. Phase composition as well as dependence of failure stress and plasticity of YBa2Cu3O7-x + ZrO2 HTSC ceramics specimens has been studied. It is observed that doping of such ceramics with certain amount of zirconium dioxide reveals forming the nanostructured phase located in the intergranular areas of the material that causes significant strengthening of the materials at low temperatures and at the same time makes the material deformab le at the elevated temperatures. Peculiarities of structure and mechanical behaviour of rapidly quenched Al-Sc alloys are studied. It is shown that application of rapid solidification method to aluminium alloyed with Sc allows formation of the nanophase material with enhanced mechanical properties.