Characterization of the elastic-plastic behavior of intermetallic coatings growth on medical stainless steel by instrumented ultramicroindentation.
J Mech Behav Biomed Mater
; 16: 1-8, 2012 Dec.
Article
em En
| MEDLINE
| ID: mdl-23137617
ABSTRACT
The purpose of this work is to study the elastoplastic properties of novel intermetallic coatings grown by hot dipping on medical steel 316 LVM and their correlation with the scratch resistance by means of instrumented ultramicroindentation techniques. Elastoplastic properties are defined by the plasticity index (PI), which correlates the hardness and the Young's modulus, and the yield strength that delimits the elastic-plastic transition. To avoid overestimations of the PI due to the so-called indentation size effect, macroscopic hardness values were determined. The PI of the coating increases from 0.6 to 0.8 with increasing immersion time. These values are always lower than those of the bare substrate (0.9) but higher than those found for ceramics (â¼0.5). The increase of the PI is accompanied by a decrease in the yield strength from 0.73 to 0.34 GPa, which highlights the relevance of the compressive residual stresses and their relaxation with increasing immersion time. The higher plasticity is shown by higher apparent friction coefficients (0.159), which are always lower than those of the bare steel (0.264). Therefore, these intermetallic coatings could be considered "hard but tough" coatings, suitable for enhancing the wear resistance of the medical steel, especially when using short periods of immersion. The study provides evidence that the load-depth curve of indentation contains abundant information and that its analysis can be used to determine various mechanical properties of coatings that could be important for load bearing components.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aço Inoxidável
/
Materiais Biocompatíveis
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Teste de Materiais
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Elasticidade
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Módulo de Elasticidade
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Microtecnologia
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Testes de Dureza
Idioma:
En
Revista:
J Mech Behav Biomed Mater
Assunto da revista:
ENGENHARIA BIOMEDICA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Espanha