Effect of Microstructure on the Tribological and Mechanical Properties of CuO‐Doped 3Y‐TZP Ceramics

Abstract

Dense 8 mol% CuO‐doped 3Y‐TZP ceramics were prepared by pressureless sintering for 8 h at 1500° and 1550°C, respectively. Transmission electron spectroscopy revealed that the ceramic sintered at 1500°C exhibits grain boundaries free of any amorphous phase, while crystalline copper‐oxide grains were found in the zirconia matrix, whereas the sample sintered at 1550°C contains a Cu‐rich amorphous grain boundary layer. The tribological behavior of these materials was tested under dry‐sliding conditions using a pin‐on‐disk tribometer. The material sintered at 1500°C showed self‐lubrication resulting in a low coefficient of friction (f) of 0.2–0.3 and a low specific wear rate (k) ≪ 10−6 mm3·(N·m)−1. In contrast, the material sintered at 1550°C showed poor tribological behavior (f=0.8–0.9; k≫ 10−6 mm3·(N·m)−1 under the same conditions. The difference in the tribological behavior of these two materials was interpreted on the basis of mechanical properties and microstructural characteristics.

Analysis of reactions during sintering of CuO-doped 3Y-TZP nano-powder composites

“…[1][2][3][4] These properties extend the materials' potential applications into near net shape forming of ceramics 1 and as a solid lubricant. [2][3][4] During sintering of CuO-doped Y-TZP systems several reactions occur.…”

“…[1][2][3][4] These properties extend the materials' potential applications into near net shape forming of ceramics 1 and as a solid lubricant. [2][3][4] During sintering of CuO-doped Y-TZP systems several reactions occur. [4][5][6][7][8][9][10][11] These reactions have profound influences not only on sintering behaviour but also on the microstructure of the final ceramic.…”

“…[2][3][4] During sintering of CuO-doped Y-TZP systems several reactions occur. [4][5][6][7][8][9][10][11] These reactions have profound influences not only on sintering behaviour but also on the microstructure of the final ceramic. It is observed in course-grained systems that these reactions retard densification [4][5][6] and result in a tetragonal to monoclinic zirconia phase transformation during sintering.…”

Manipulating microstructure and mechanical properties of CuO doped 3Y-TZP nano-ceramics using spark-plasma sintering

“…CuO doped 3Y-TZP (3 mol% yttria stabilised tetragonal zirconia polycrystals) composite ceramics have shown special properties including large superplasticity 1,2 and low friction under dry sliding conditions, 3,4 which make this group of material interesting for applications like near net shape forming of ceramics and moving parts to operate under unlubricated conditions. Mechanical properties such as hardness, strength and toughness are also important for potential applications.…”

Nano Si3N4 composites with improved tribological properties

“…The disadvantage of thin coatings with self-lubricating properties was found to be coating failure due to their limited layer thickness and bonding strength. Therefore, the incorporation of a self-lubricating phase such as graphite, 1 molybdenum disulphide, 2 boron nitride, 3 tungsten carbide, 4 or copper oxide [5][6][7] in silicon nitride or tetragonal zirconia (TZP) composites was recently investigated. Boron Nitride (BN) addition to Si 3 N 4 allowed only a slight reduction of the friction coeffi cient caused by the degradation of the mechanical properties in case of higher content of BN.…”