To the design of grain structure in ceramics

DOI: 10.62564/M4-GO1558

Galina Oleynik, Andrii Kotko

Frantsevich Institute for Problems of Materials Science National Academy of Science of Ukraine


Design of ceramics with predetermined microstructure is based on the arrangement of concordant structure transformations under sintering of selected phase components, whose evolution determines the formation of required microstructure elements, their crystal morphology, scale, content, and distribution throughout the volume. Such elements may include grains, intergrain and interphase boundaries, elements of substructure responsible for the appearance of intragrain boundaries,such as dislocation, twinning, domain, and interphase ones, and pores of different types. Knowledge of these mechanisms is the base for design of novel materials an dimprovement of the currentones. The grain structure is a basic material structure component. Based on our research (using TEM with microdiffraction and SEM with microanalysis) and literature data, general regularities of grain structure formation in ceramics are considered in the course of primary (PR) and collective (CR) recrystallization and during formation of composites under sintering. It’s worth noting that recrystallization in ceramics was first studied by G.V. Samsonov at our Institute. PR in ceramics can occur under different conditions of loading such as free sintering, hot pressing including that under highpressure, uniaxial compression, rolling, friction, etc. The structural mechanisms of the PR evolution in ceramics are similartometals. The formation of grain structure in composites is determined by structure transformations due to the contact interaction of phase components; transformations in the grain volume of initial phases (plastic fragmentation, polymorphic transformations, decomposition of solid solutions, twinning, domainization, etc.); transformations in grain boundaries (phase transitions, boundary faceting, etc.). All of them lead to refining grain structure due to the formation of new grains and saturation of the initial ones with internal boundaries resulting from substructure formation [1].

Keywords
Microstructure, design, recrystallization, transformation

Acknowledgments
Not provided

References
[1] Oleynik G.S. Structure formation of ceramic materials. Kyiv: Naukova dumka, 2018, 352 p.