Alumina-Toughened-Zirconia with Low Wear Rate in Ball-on-Flat Tribological Tests at Temperatures to 500 °C.

Marek Grabowy,Grzegorz Wiązania,Magdalena Ziąbka,Zbigniew Pędzich,Agnieszka Wojteczko,Maciej Łuszcz,Kamil Wojteczko

doi:10.3390/ma14247646

Abstract

An alumina-toughened zirconia (ATZ) material, fabricated using a procedure consisting of the common sintering of two different zirconia powders, was tested using the ball-on-disc method in a temperature range between room temperature and 500 °C. Corundum balls were used as a counterpart. The ATZ composite behaviour during tests was compared with that of commonly used α-alumina and tetragonal zirconia sintered samples. At temperatures over 350 °C, a drastic decrease in the wear rate of the material was detected. SEM analyses proved that, in such conditions, nearly the whole surface of the sliding material was covered with a layer of deformed submicrometric grains, which limited contact with the part of material that was not deformed. The mentioned layer was relatively strongly connected with the material, increased its resistance, and decreased its coefficient of friction. As a reference, commonly used materials, namely commercial alumina and tetragonal zirconia, were tested. The wear parameters of the composite were significantly better than those registered for the materials prepared of commercial powders.

Highlights

Continuous development of ceramics technology is a clear condition for the improvement of many branches of industry [1]
The modification of the TZP material (Z) involved the addition of a small amount of α-alumina submicrometric particles and the utilization of the sintering process assisted with intensive yttrium cations migration from using two different zirconia powders, which led to composite materials with a very fine grain size and small amount of monoclinic phase (ATZ)
The surface layer created during the dry sliding of counterpart on the material surface from room temperature became almost continuous

Summary

Introduction

Continuous development of ceramics technology is a clear condition for the improvement of many branches of industry [1]. A good example is knee or hip-joint ceramics endoprosthesis [2,3], but the mentioned ATZ materials have a significantly wider field of application in the machinery industry. In alumina/zirconia materials, the zirconia phase is always under tension and alumina under compression Values of these stresses depends on individual phase content and grains size and shape. The aim of the presented paper was to use a zirconia matrix in the ATZ composite as a specific material with a fine microstructure and high tendency to the tetragonal to monoclinic phase transformation, which could assure a high level of mechanical and tribological properties [14,15,16,17,18]

Methods

Results

Discussion

Conclusion