The presented work concerns the development and investigation of three different grades of ZrO₂ materials containing Al₂O₃ particles (ATZ-Alumina Toughened Zirconia ceramics with 2.3–20 vol.% of alumina). The zirconia powders containing 3 mol.% of yttria were synthesized by a precipitation/calcination method and fabricated from two different zirconia powders with different yttria content. Then, the selected ATZ composites (ATZ-B, ATZ-10 and ATZ-20) were prepared by means of conventional mixing, compacting and sintering at 1450 °C for 1.5 h. The phase composition, microstructure, relative density and basic mechanical properties were determined. Uniform microstructures with relative densities over 99% of theoretical density, hardness values between 12.0–13.8 GPa, flexural strength up to 1 GPa and outstanding fracture toughness of 12.7 MPa⋅m^1/2 were obtained. The aging susceptibility of alumina toughened zirconia materials, as a consequence of hydrothermal treatment, was investigated. The aim of this study was to determine the influence of LTD (low temperature degradation) on the tetragonal to monoclinic phase transitions and on the flexural strength of hydrothermally aged specimens. The results were compared to those obtained for commercially available tetragonal zirconia-based materials containing 3 mol.% of yttria. This research shows that ATZ composites that have excellent mechanical properties and sufficient hydrothermal aging resistance can be attained and later used in technical and biomedical applications.

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.

Paper presents selected properties of a kind of alumina toughened zirconia (ATZ) composites manufactured by the method which utilize reactive sintering process. Products made by means of this process show many perspective properties which could improve their usefulness as machinery parts materials. These properties comes from much finer microstructure than this obtained in typical AZT or TZP (tetragonal zirconia) materials. Special advantages mentioned materials showed in tribological applications connected with sliding cooperation without any lubrication at temperatures exceeded 300 °C like rolling elements of machinery or parts subjected to intensive abrasion. Another potential field of application is area when working elements are subjected to stable load under critical value. Actually, in ever known oxide materials at such conditions slow crack propagation phenomenon occurs. In a new type of ATZ materials this phenomenon could be distinctly limited or even stopped. In the paper we present a results of investigations which confirm high level of useful properties detected in a new type of ATZ composites.

With each passing year, multi-layered armours for military vehicles become more and more advanced to meet growing demands and counterpart novel offensive solutions. Layers that are responsible for track deviation and blunting of the projectile, typically made of hard ceramics, are nowadays considered to be replaced by ceramic composite. In this study, two ceramic systems composed of the TiB2 matrix and SiC or SiC/TiC reinforcement phases were fabricated from mixture of B4C powder with different amount of TiSi2 or Ti5Si3 intermetallic phases. Importantly, the desirable microstructure was obtained by reactive sintering at 1550?C and pressure of 2.5GPa. The obtained ceramic composites underwent dynamic loading tests to evaluate their applicability for ballistic shields. Two systems were then compared in terms of the potential pulverization rate which determines usability as a primary layer for a multi-layered vehicle armour.

In this article, the impact of microstructure on the mechanical properties of silicon nitride materials obtained by the liquid-phase sintering method was investigated. Using image analysis based on the two-point correlation method, the relationship between the autocorrelation length (ACL) parameter and the homogeneity of the microstructure and its impact on mechanical properties were examined. It was shown that lower ACL values, indicating greater microstructure homogeneity, correlate with better mechanical properties, such as bending strength, hardness and fracture toughness. The two-point correlation analysis demonstrated advantages over traditional microstructural analysis methods, offering efficiency, precision and automation capabilities, which are crucial for quality control in the industry.