WEB Study of microstructure and mechanical properties of cold sintered ZnOTuesday (22.09.2020) 10:55 - 11:10 P: Processing and Synthesis 1 Part of:
Mechanical properties of functional ceramics are determined by their final sintered density. High temperature (0.5 – 0.7 of melting point) diffusion is normally required for pressed ceramic powders to achieve an acceptable final density. In the present study, cold sintering was used for the densification of ZnO nanosized particles (40-100 nm) with deionized water as a sintering aid. Almost full densification (98-99%) was achieved at only 250 ℃ for ZnO (with melting point of 1975 ℃) using 300 MPa and merely 20 min of dwell time The developed microstructure was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). This confirmed the suppression of the grain growth less than 200 nm in the cold sintered pellets. Also, TEM revealed fine grains with well formed grain boundaries. Mechanical properties of the cold sintered pellets were measured by nanoindentation using a Berkovich indenter. The values of average hardness (4.47±0.38 GPa) and average modulus (109±5 GPa) agree well with the values reported in the literature for ZnO thin films and bulk ZnO single crystal.