Abstract:
This paper investigates the effect of two-step sintering on the mechanical properties and microstructure of
Sm2Zr2O7 ceramics obtained from submicron powders after high-energy milling. Two key parameters of the twostep sintering process are analyzed: temperature and duration, as both can significantly influence grain growth
processes in ceramics. It was found that extending the sintering duration at lower temperatures promotes ceramic
densification while preserving a relatively narrow grain size distribution. In contrast, higher sintering temper
atures combined with shorter durations result in broader grain size distributions and more pronounced exag
gerated grain growth. Despite differences in microstructure and grain size distribution, both the sample sintered
at 1350 ◦C for 20 hours and the one sintered at 1700 ◦C for 10 minutes exhibited the highest mechanical
properties, with microhardness values HV1 ~1200 and biaxial flexural strength reaching ~125 MPa. This
suggests that the enhancement of mechanical performance may be linked to a reduction in internal stresses,
either due to the elevated temperature during the first sintering step or the extended holding time during the
second step. Thus, in both types of sintering, whether based on prolonged holding time or elevated temperature,
changes in sample morphology and grain size do not appear to have a significant impact on the mechanical
properties of the resulting ceramics.
