# Yttria-Calcia-Co-Stabilized Tetragonal Zirconia Polycrystals Made by Powder Mixing

## TL;DR

Researchers made yttria-calcia-stabilized zirconia by mixing powders, finding it has good mechanical strength and resistance to degradation, suitable for biomedical use.

## Contribution

A new yttria-calcia-stabilized zirconia material is produced via powder mixing with balanced mechanical properties and LTD resistance.

## Key findings

- Mechanical properties and LTD resistance of Y-Ca-TZP are between Y-TZP and Ca-TZP.
- Lower sintering temperatures improve strength and LTD resistance.
- Powder mixing allows easy production of standard Y-Ca-TZP compositions.

## Abstract

Main findings:
Yttria-calcia-co-stabilized zirconia can be obtained by powder blending;The values of mechanical properties and Low temperature degradation (LTD) resistance are between those of Y-TZP (tetragonal zirconia polycrystalline) and Ca-TZP;Low sintering temperature favors strength and LTD resistance.

Yttria-calcia-co-stabilized zirconia can be obtained by powder blending;

The values of mechanical properties and Low temperature degradation (LTD) resistance are between those of Y-TZP (tetragonal zirconia polycrystalline) and Ca-TZP;

Low sintering temperature favors strength and LTD resistance.

Implications of the main findings:
Y-Ca-TZP materials may be interesting for biomedical applications;Further improvements may be possible by adjusting fractions and stabilizer contents of the starting powders;Powder mixing provides easy access to some standard compositions.

Y-Ca-TZP materials may be interesting for biomedical applications;

Further improvements may be possible by adjusting fractions and stabilizer contents of the starting powders;

Powder mixing provides easy access to some standard compositions.

In this study, 1.5Y-2.2Ca-TZP materials were obtained by hot pressing of a mixed and milled blend of 3Y-TZP and 4.4Ca-TZP powders. The materials were sintered at temperatures between 1250 °C and 1400 °C and characterized with respect to mechanical properties, microstructure, phase composition and stability against low-temperature degradation. In the tested range, the bending strength of the TZP decreases with increasing sintering temperature from 1300 MPa to 1050 MPa while the toughness shows a rising trend from 5 MPa√m to 8 MPa√m. The grain size distribution in the microstructure is broad with average grain sizes increasing from 150 nm to 250 nm with rising sintering temperature. LTD tests revealed high aging resistance for TZP sintered at 1300 °C. The Y-Ca-co-stabilized TZP equilibrates the properties of Ca-TZP and Y-TZP.