Abstract: In this paper, alumina-zirconia ceramics with different contents of strontium hexaaluminate are investigated. Materials were obtained by pressing granulated powder and following free sintering. An XRD analysis was carried out. The structure was studied using a scanning electron microscope. Vickers hardness was determined at a load of 10 kg. Fracture toughness was evaluated using the indentation method. The change of composites structure at different temperatures was analyzed. The growth of SrAl12O19 platelet length proceeds predominantly up to 1400 °C. The platelet length range from 0.30 μm to 1 μm. At a temperature of 1500 °C the platelets thickness increases. In materials sintered at 1520 °C for 5 h with an increase in the SrAl12O19 content, the relative density decreases, and the porosity of the materials increases. Increasing the strontium hexaaluminate content in sintered materials decreases the alumina grain size. With strontium hexaaluminate content of 15 wt %, the average grain size of the alumina component decreases by 19% compared to unaided alumina ceramics (from 0.74 ± 0.06 to 0.60 ± 0.04 μm). With increasing SrAl12O19 content, the length of the platelets increased one and a half times from 0.80 μm to 1.20 μm. The width of the platelets remained essentially unchanged. Formation of strontium hexaaluminate platelets in materials and increase of its content contribute to increasing of fracture toughness of alumina-zirconia ceramics. The maximum level of fracture toughness is recorded at 15 wt % strontium hexaaluminate and is 7.7 ± 0.3 MPa*m1/2. The hardness of the composite with 15 wt % SrAl12O19 is 18% lower than alumina zirconia ceramics and is ∼1400 HV. Mechanisms for increasing the fracture toughness of alumina-zirconia ceramics depend on the strontium hexaaluminate content. At hexaaluminate strontium content up to 6 wt %, bending, platelet fracture, and bridging mechanisms are observed. At 9 and 12 wt % SrAl12O19 deflection mechanisms, crack branching and platelets fracture were detected. At 15 wt % SrAl12O19 the crack deflection is observed. © 2022 Elsevier B.V.

Cite: Cherkasova N. , Kuzmin R. , Veselov S. , Antropova K. , Ruktuev A. , Ogneva T. , Tyurin A. , Kuchumova I. , Khabirov R.
Influence of strontium hexaaluminate percentage on the structure and properties of alumina-zirconia ceramics
Materials Chemistry and Physics. 2022. V.288. 126424 :1-8. DOI: 10.1016/j.matchemphys.2022.126424 WOS Scopus РИНЦ OpenAlex

Dates:

Submitted:	Mar 9, 2022
Accepted:	Jun 15, 2022
Published online:	Jun 17, 2022

Identifiers:

Web of science:	WOS:000826807000004
Scopus:	2-s2.0-85132521710
Elibrary:	49132670
OpenAlex:	W4283032615

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