Nacre-like alumina composites based on heteroaggregation

Mariana Muňoz (1) , Manuella Cerbelaud (1) , Arnaud Videcoq (1) , Hassan Saad (2) , Alexandre Boulle (3) , Sylvain Meille (4) , Sylvain Deville (2, 5) , Fabrice Rossignol (1)

1 IRCER-AXE1 - IRCER - Axe 1 : procédés céramiques
2 LSFC - Laboratoire de Synthèse et Fonctionnalisation des Céramiques
3 IRCER - Institut de Recherche sur les CERamiques
4 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
5 iLM - L&I - iLM - Liquides et interfaces

High strength and high toughness are usually mutually exclusive in materials. Among all material classes, ceramics exhibit a high stiffness and strength, but they present a limited plastic deformation, which results in a moderate toughness. However, tough ceramics have been obtained using anisotropic particles organized in a 'brick and mortar' microstructure, inspired by the structure of the natural nacre. Here, we propose to build nacre-like ceramic composites from colloidal suspensions using heteroaggregation of particles. Two different shaping processes are used: direct settling of suspensions or freeze-granulation. After sintering, in both cases, the platelets alignment is very good, close to that of platelets in natural nacre, with a slightly better one noted for direct settling. Despite a better platelet alignment, the toughness is lower than in previous studies showing that further improvement of the interfacial phases present in the material must now be considered to reinforce its mechanical behavior.

Mots clés: Nacre-like composite; Heteroaggregation; Platelet alignment; Settling; Freeze-granulation

Domaines: Sciences de l'ingénieur [physics]; Chimie; Physique [physics]

Mariana Muňoz, Manuella Cerbelaud, Arnaud Videcoq, Hassan Saad, Alexandre Boulle, et al.. Nacre-like alumina composites based on heteroaggregation. Journal of the European Ceramic Society, 2020, 40 (15), pp.5773-5778. ⟨10.1016/j.jeurceramsoc.2020.06.049⟩. ⟨hal-02938571⟩