title: Self-lubricating, low-friction, wear-resistant Al-based quasicrystalline coatings.
abstract: After gas atomization, a quasicrystalline powder based on aluminium was used to prepare a thick coating by high-velocity oxygen-fuel flame torch spraying. This layer was deposited on top of a bond-coat layer on a steel plate. A post-spraying annealing treatment turned the two layers to their stable state, a γ-brass crystal and an icosahedral quasicrystal, respectively. The projection parameters were selected in such a way that the coating behaved like a self-lubricating material, which offered very good wear resistance (duration of pin-on-disk tests superior to 5 km with negligible material loss) and low friction (µ ≤ 6% against sintered tungsten carbide), in contrast to the state of the art. This property was achieved thanks to, on the one hand, excellent bonding to the substrate via the bound coat, and on the other hand, presence at the boundaries between quasicrystalline flakes of a mixture of both threefold and fourfold coordinated carbon originating from spray processing. Application to hard materials used in mechanical devices is appealing, especially because soft, lubricating additives may not be needed, thus considerably increasing the lifetime of the devices and reducing waste of materials.
authors.affiliation: Laboratório de Solidificação Rápida, Universidade Federal da Paraíba, João Pessoa-PB, Brazil; Institut Jean Lamour (UMR 7198 CNRS - Université de Lorraine), Parc de Saurupt, CS50840, 54011Nancy, France.
authors.forename: Bruno Alessandro
authors.initials: BA
authors.lastname: Silva Guedes de Lima
authors.affiliation: Laboratório de Solidificação Rápida, Universidade Federal da Paraíba , João Pessoa - PB , Brazil.
authors.forename: Rodinei
authors.initials: R
authors.lastname: Medeiros Gomes
authors.affiliation: Laboratório de Solidificação Rápida, Universidade Federal da Paraíba , João Pessoa - PB , Brazil.
authors.forename: Severino Jackson
authors.initials: SJ
authors.lastname: Guedes de Lima
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux (UMR 8182 CNRS- Université Paris-Sud 11) , Bât. 410, 15 rue Georges Clémenceau, 91405 Orsay Cedex , France.
authors.forename: Diana
authors.initials: D
authors.lastname: Dragoe
authors.affiliation: Institut de Chimie Moléculaire et des Matériaux (UMR 8182 CNRS- Université Paris-Sud 11) , Bât. 410, 15 rue Georges Clémenceau, 91405 Orsay Cedex , France.
authors.forename: Marie-Geneviève
authors.initials: MG
authors.lastname: Barthes-Labrousse
authors.affiliation: Institut Jean Lamour (UMR 7198 CNRS - Université de Lorraine) , Parc de Saurupt, CS50840, 54011 Nancy , France.
authors.forename: Richard
authors.initials: R
authors.lastname: Kouitat-Njiwa
authors.affiliation: Institut Jean Lamour (UMR 7198 CNRS - Université de Lorraine) , Parc de Saurupt, CS50840, 54011 Nancy , France.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Dubois
keywords: 10; 106; 206; 212; 306; 501; 504; Coatings; friction; quasicrystals; self-lubrication; wear