SEM AND TEM STUDIES ON CREEP DEFORMATION OF ALUMINA AND ALUMINA-CARBON NANO COMPOSITE DENSIFIED BY SPS

Spark plasma sintering method (SPS) has been studied as an alternative method to obtain dense finegrained ceramics at lower temperatures and at increased sintering rates. Regarding the alumina densification case, some compounds are well known to help during sintering at limiting also grain growth and resulting grain size (such as MgO and ZrO2). Many mechanical properties depend on the grain size, as the plasticity. As a matter of example the overall deformation capabilities of allceramics will be altered by SPS and by all grain growth limiting techniques, in particular alumina based ceramics. This study focuses on SEM and TEM microstructures of alumina materials creep deformed and on the beneficial effects of SPS and of introducing carbon particles in the aluminamatrix on limiting grain growth and on extending high temperature deformation plasticity for materials densified by SPS. Here are presented creep deformation results and deformation mechanisms of pure alumina (hereafter AP/SPS) and of carbon particles containing alumina based material (hereafter AC/SPS), both densified by SPS. Considering the SEM microstructures, thefineness of microstructure obtained by SPS is shown to be more effective when combined with carbon nano particles. Hence plasticity is eased for AC/SPS nano composite material.

کلیدواژه ها:

SEM ، TEM ، Creep ، Alumina ، SPS ، Nano Composite