Relationship between mechanical properties and microstructure of yttria stabilized zirconia ceramics densified by spark plasma sintering

Abstract

To cite this version:Arnaud Fregeac, Florence Ansart, Serge Selezneff, Claude Estournès. Relationship between mechanical properties and microstructure of yttria stabilized zirconia ceramics densified by spark plasma sintering.OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible Any correspondence concerning this service should be sent to the repository administrator: tech-oatao@listes-diff.inp-toulouse.fr This is an author's version published in: http://oatao.univ-toulouse.fr/24381 To cite this version:Fregeac, Arnaud and Ansart, Florence and Selezneff, Serge and Estournès, Claude Relationship between mechanical properties and microstructure of yttria stabilized zirconia ceramics densified by spark plasma sintering. (2019) Ceramics International, 45 (17Porous ceramics are widely used for many applications such as filters, insulators, electrodes for SOFC, membranes or bone scaffolds, with porosity in the typically range of 20-50%vol. The functionality of those materials comes at the expense of the degradation of their mechanical properties which are highly impacted by the rate, distribution, shape and size of the porosity. Among them tetragonal stabilized zirconia (TSZ) is one of the most industrially used; it is sometime called: "the ceramic steel" since in its dense state it exhibits the highest toughness for ceramics. It is known that the porosity has a huge impact on the thermo-mechanical properties of refractory ceramics as Yittria Stabilized Zirconia (YSZ). This study aims to capitalize the mechanical properties as a function of porosity to provide future applications and ensure the behavior in service of thermal barrier coating.In the present paper, the correlation between the microstructure and the mechanical properties such as Young modulus, hardness and strength of YSZ ceramics obtained by Spark Plasma Sintering (SPS) was investigated. Two types of YSZ powder, a nanometric one from Tosoh and a micrometric one obtained by sol-gel route were studied to prepare homogeneous mesoporous or oriented macroporous microstructure by partial sintering. SPS parameters have been determined and optimized to manage the porosity rate. Furthermore, a bimodal microstructure can be obtained, by mixing both powders, allowing the formation of linking bridges between the microporous zone and the nanopowder during sintering. The macroporous ceramics have lower Young modulus, hardness and strength than mesoporous ones. These characteristics are discussed in the paper taking into account the differences between microstructure and contacts between particles with various form factors. Thus, it is clearly evidenced that the morphology of raw powders and the level of porosity are key parameters to optimize the mechanical properties of such porous material.

Flash Spark Plasma Sintering of 3YSZ: Modified sintering pathway and impact on grain boundary formation

“…The same HV evolution with density was observed in zirconia with higher Y 2 O 3 contents, i.e. 6 and 8 mol.% in YSZ [29,30]. In the present case, the FSPS specimen exhibited hardness values above the typical data obtained for a dense specimen, although FSPS specimens contain 5 15 vol.% porosity.…”

“…The Vickers hardness (HV) of the FSPS sintered specimens were presented in Fig. 6, and compared to the literature data from Muroi et al [27], Luo & Stevens [28] and Fregeac et al [29].…”

A Review on Processing Routes, Properties, Applications, and Challenges of Titanium Metal Matrix Composite

“…In the PM fabrication technique, the metal removal process is usually avoided so that the yield loss is decreased while manufacturing the fabric which ends up lowering the prices and material wastage as compared to the casting process. It's an efficient process of controlling the components, i.e., matrix and reinforcement dispersion ratio in a very powder form using the varied jar, ball milling methods, etc within the composites [22,23]. The powder metallurgy routes are applicable for advanced materials for Aerospace, like functionally graded materials.…”

Does speed-sintering affect the optical and mechanical properties of yttria-stabilized zirconia? A systematic review and meta-analysis of in-vitro studies

“…Because cracking can occur during rapid heating and cooling [18] , [19] , a low heating rate (5–10 °C/min) and long dwell time (2–4 h) are typically used to achieve uniform heat distribution and optimum sintering [16] , [20] . In contrast, techniques such as microwave sintering [18] , [21] , induction heating [16] , [22] , flash sintering [23] , [24] , [25] , [26] , cold sintering [27] , [28] , [29] , spark plasma sintering [30] , [31] , hot-pressing [32] , and selective laser sintering [33] can shorten the total sintering time and reduce the energy consumption. The application of some of these procedures to YSZ is currently being investigated.…”