CERAMICS INTERNATIONAL Available online at www.sciencedirect.com Ceramics International 40 (2014) 11433–11436 Short communication High-temperature mechanical behavior of plasma sprayed lanthanum zirconate coatings G. Di Girolamo a,n , F. Marra b , C. Blasi c , M. Schioppa c , G. Pulci b , E. Serra a , T. Valente b a ENEA, Materials Technology Unit, Casaccia Research Centre, Rome, Italy b Department of Chemical Engineering Materials Environment, Sapienza University of Rome, INSTM Reference Laboratory for Engineering of Surface Treatments, Rome, Italy c ENEA, Materials Technology Unit, Brindisi Research Centre, Brindisi, Italy Received 16 December 2013; received in revised form 20 March 2014; accepted 20 March 2014 Available online 28 March 2014 Abstract Rare-earth zirconates are potential materials for thermal barrier coatings. Their properties are not still well known, due to any lacks in processing and characterization techniques. To this purpose lanthanum zirconate coatings were herein manufactured by plasma spraying. The coatings exhibited high porosity, due to the presence of pores, splat boundaries and microcracks. The high-temperature evolution of mechanical properties was investigated by arranging specific bending tests up to 1500 1C using SiC testing assembly which allows to reconstruct and measure the sample curvature and the deformation. At higher temperatures the coatings showed an inelastic behavior, related to their unique microstructure, as well as a toughening effect. & 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Keywords: C. Mechanical properties; E. Thermal applications; Plasma spraying 1. Introduction Ceramic thermal barrier coating (TBC) systems are adopted to protect the surface of metal parts operating in harsh environments, such as turbine blades, vanes and shrouds, which typically suffer fast and severe degradation, due to the simultaneous presence of extreme temperatures, oxidative, corrosive and erosive agents [1]. Thermal barrier coatings are able to reduce the heat flux to the metal surface and the environmental attack, then increasing the turbine efficiency and reducing the fuel consumption. Yttria stabilized zirconia (YSZ) is the state-of-the-art material employed for TBCs fabrication, but only for restricted applications. Indeed, at temperature higher than 1200 1C the sintering of the porous microstructure reduces the compliance and increases the thermal conductivity, negatively affecting the thermal cycling durability [2]. Therefore, new efforts are needed in order to find alternative compositions involving better temperature capability and service performance. Lanthanum zirconate is a good candidate for TBC development, due to its low thermal conductivity and high thermal stability [3,4]. However, it has been reported that lanthanum zirconate can exhibit some restrictions for real applications, related to low toughness and relatively low thermal expansion coefficient [5]. Plasma spraying is an industrially available technology which allows to fabricate well-tailored microstructures char- acterized by low thermal conductivity and high compliance, and then can be properly employed to produce highly performant lanthanum zirconate TBCs. To this purpose, it is an important key issue to study their high-temperature mechanical behavior in order to explore new perspectives about alternative TBCs and related coated turbine components. Indeed, there is a lack in the study of these subjects as well as www.elsevier.com/locate/ceramint http://dx.doi.org/10.1016/j.ceramint.2014.03.110 0272-8842/& 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved. n Corresponding author. E-mail address: giovanni.digirolamo@enea.it (G. Di Girolamo).