A Key Catalyst in Advancing Zirconia Ceramics Manufacturing

2024-01-17

In today's ceramic manufacturing field, zirconia ceramics are highly favored for their outstanding wear resistance,

high temperature stability, chemical stability, and strength. However, the preparation of zirconia ceramics requires

high-quality raw materials and precision in the production process, with ammonium fluozirconate undoubtedly

being one of the crucial materials. This article will introduce the application of ammonium fluozirconate in the

preparation of zirconia ceramics and its underlying mechanisms.

Ⅰ. Methods for the Preparation of Zirconia Ceramics and their Pros and Cons

There are various methods for preparing zirconia ceramics, including hot isostatic pressing, injection molding,

coaxial molding, and atmospheric plasma spraying. Among them, hot isostatic pressing is widely used due to its high

forming precision and density.

The main process of hot isostatic pressing involves uniformly mixing zirconia powder and additives, pressing the mixture

into shape under high pressure, and subsequently subjecting it to high-temperature sintering. However, the quality and purity

of zirconia powder significantly impact the final product's performance. Therefore, the preparation of zirconia ceramics necessitates

the use of high-quality zirconia powder, involving strict processes of mixing, pressing, and sintering. This highlights the crucial role of

ammonium fluozirconate in the preparation of zirconia ceramics.

Ⅱ. Application of ammonium fluozirconate in the Preparation of Zirconia Ceramics

1、Chemical Properties of ammonium fluozirconate

ammonium fluozirconate has the molecular formula ZrF2·NH4F and exhibits high thermal stability and solubility. It undergoes acid hydrolysis

in water, producing zirconia and hydrogen fluoride, as indicated by the reaction:

ZrF₂•NH₄F+H₂O→ZrO₂+2HF+NH₄F

Therefore, ammonium fluozirconate plays a role in catalyzing the decomposition of zirconia precursors, regulating the size of zirconia grains,

increasing zirconia density, and inhibiting the growth of zirconia grains during the preparation of zirconia ceramics.

2、Application of ammonium fluozirconate in the Preparation of Zirconia Ceramics

（1）Catalyzing the Decomposition of Zirconia Precursors

ammonium fluozirconate can act as a co-catalyst for zirconia precursors, accelerating their thermal decomposition at high temperatures and

facilitating the formation of zirconia. By adjusting the quality and quantity of ammonium fluozirconate, the size and distribution of zirconia

grains can be controlled, thereby influencing the final product's performance.

（2）Regulating the Size of Zirconia Grains

The size and shape of zirconia grains directly impact the mechanical properties and chemical stability of ceramics. Compared to pure zirconia,

the addition of ammonium fluozirconate promotes the refinement and uniform distribution of zirconia grains, enhancing the strength and density of ceramics.

（3）Increasing Zirconia Density

Pores and other defects can reduce the density and mechanical properties of zirconia ceramics. The addition of ammonium fluozirconate

prevents the formation of pores in zirconia ceramics, thereby improving their density and strength.

（4）Inhibiting the Growth of Zirconia Grains

Zirconia grains tend to grow at high temperatures, compromising the mechanical properties of ceramics. The inclusion of ammonium fluozirconate

helps suppress the growth of zirconia grains, maintaining their small and uniform distribution.

Zirconia ceramics represent a highly promising engineering material with extensive application prospects. However, the preparation of zirconia

ceramics demands high-quality raw materials and precise production processes, with ammonium fluozirconate undeniably playing a vital role.

ammonium fluozirconate exhibits multiple functions in the preparation of zirconia ceramics, including catalyzing the decomposition of zirconia precursors,

regulating the size of zirconia grains, increasing zirconia density, and inhibiting the growth of zirconia grains. Its role becomes particularly prominent

in forming processes such as hot isostatic pressing and coaxial molding. It is anticipated that ammonium fluozirconate and its research will exert a greater

influence in the field of zirconia ceramics preparation.