Nanomechanical properties of rough surfaces

Materials Research

Gelson Biscaia De Souza²  Carlos Eugênio Foerster¹  Silvio Luiz Rutz Da Silva¹  Carlos Maurício Lepienski¹ 

[1] ,Universidade Estadual de Maringá Campus Regional de Goioerê Departamento de CiênciasGoioerê PR ,Brazil

关键词: nanoindentation;    roughness;    nitriding;    titanium;   

DOI  :  10.1590/S1516-14392006000200009

来源: SciELO

【 摘 要 】

The nanoindentation technique allows the determination of mechanical properties at nanometric scale. Hardness (H) and elastic modulus (E) profiles are usually determined by using the Oliver-Pharr method from the load/unload curves. This approach is valid only for flat surfaces, or at least, when a very low degree of asperity is present (lower than 30 nm). The basic statement is the determination of the zero tip-surface contact point. If a rough surface is present, errors can occur in determining this contact point and, as a consequence, the surface hardness and elastic modulus profiles are drastically altered resulting in under evaluated values. Surfaces with different roughness were produced by controlled nitrogen glow discharge process on titanium. The changed nitriding parameters were different N2/H2 atmospheres and temperatures (600 °C-900 °C). The most correct H and E profiles were obtained by using the contact stiffness analysis method, proposed here, that overcomes the surface roughness. The obtained results were compared with available literature data.

【 授权许可】

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