Microstructural and superficial modification in a Cu-Al-Be shape memory alloy due to superficial severe plastic deformation under sliding wear conditions

7th International Conference on Nanomaterials by Severe Plastic Deformation

Figueroa, C.G.^1 ; Garcia-Castillo, F.N.^2 ; Jacobo, V.H.^2 ; Cortés-Pérez, J.^1 ; Schouwenaars, R.^2

Centro Tecnológico Aragón, Facultad de Estudios Superiores Aragón, Universidad Nacional Autónoma de México, Av. Rancho Seco s/n, Col. Impulsora, Cd. Nez., Estado de Mexico

57130, Mexico^1

Departamento de Materiales y Manufactura, Facultad de Ingeniería Edificio O, Universidad Nacional Autónoma de México, Avenida Universidad 3000, Coyoacán, Ciudad de México

04510, Mexico^2

关键词: Copper based shape memory alloys;    Engineering applications;    Mechanical energies;    Microstructure characterization;    Modified surfaces;    Severe plastic deformations;    Stress induced martensitic transformation;    Tribological behaviour;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/194/1/012011/pdf
DOI  :  10.1088/1757-899X/194/1/012011

来源: IOP

【 摘 要 】

Stress induced martensitic transformation in copper-based shape memory alloys has been studied mainly in monocrystals. This limits the use of such results for practical applications as most engineering applications use polycristals. In the present work, a coaxial tribometer developed by the authors was used to characterise the tribological behaviour of polycrystalline Cu-11.5%Al-0.5%Be shape memory alloy in contact with AISI 9840 steel under sliding wear conditions. The surface and microstructure characterization of the worn material was conducted by conventional scanning electron microscopy and atomic force microscopy, while the mechanical properties along the transversal section were measured by means of micro-hardness testing. The tribological behaviour of Cu-Al-Be showed to be optimal under sliding wear conditions since the surface only presented a slight damage consisting in some elongated flakes produced by strong plastic deformation. The combination of the plastically modified surface and the effects of mechanically induced martensitic transformation is well-suited for sliding wear conditions since the modified surface provides the necessary strength to avoid superficial damage while superelasticity associated to martensitic transformation is an additional mechanism which allows absorbing mechanical energy associated to wear phenomena as opposed to conventional ductile alloys where severe plastic deformation affects several tens of micrometres below the surface.