Modeling zirconia sintering trajectory for obtaining translucent submicronic ceramics for dental implant applications

Abstract

Attaining high densification without grain growth is one of the main objectives of the sintering optimization in ceramic materials. For dental implant applications, achieving this objective has a decisive impact on the mechanical resistance, the duration and the translucency of the implant. To improve these sintering outcomes a long experimental explorative study is generally required. In this work, we developed a combined experimental/modeling approach allowing a rapid identification of the optimal sintering conditions. The determination of the model densification and grain growth kinetic constitutive parameters has been done experimentally. We found that the sintering/grain growth kinetics have a detrimental acceleration above a critical temperature level. The pressure-less sintering model able to predict the sintering stress, powder densification and grain growth has been used for the determination of the optimal sintering trajectory. We utilized the two step sintering method to approach the critical temperature without an undesirable grain growth.We obtained translucent sintered specimens with a very limited grain growth.

Influence of sintering conditions on translucency, biaxial flexural strength, microstructure, and low-temperature degradation of highly translucent dental zirconia

“…They reported that 3Y-TZP presented a bimodal grain size distribution at a sintering temperature of 1,500°C or above, which was consistent with the results of the present study. Manière et al 42) reported the rapid increase in the grain size of Zpex Smile at a sintering temperature of 1,550°C or above. They also revealed that the slow grain growth at the sintering temperatures below 1,550°C exerted a significant influence on the intragranular porosity.…”

Fully coupled electrothermal and mechanical simulation of the production of complex shapes by spark plasma sintering

“…7. Thus, it is likely that different mechanisms occur simultaneously during the SPS of those materials as it has also been raised in the literature [22,29]. A way to improve the model would be to combine at least two mechanisms to describe the densification.…”

Additive manufacturing of powder components based on subtractive sintering approach

“…The heating cycle used was: 20°C-200°C with 5°C/min, holding at 200°C for 20 min, 200°C to 300°C with 10°C/min, holding at 300°C for 60 min, 300°C-600°C with 5°C/min, and holding at 600°C for 20 min, 600°C-1400°C with 5°C/min, 1400°C-1300°C at a rate of 5°C, holding for 10 h and cooled down at a rate of 5°C/min. The sintering cycle described above was taken from the work of Manière et al conducted on the Zpex Smile material system (Manière et al, 2020).…”