Síntese de filmes finos a-C:H pela técnica de implantação e deposição por imersão em plasma
Carregando...
Arquivos
Data
2011-12-09
Autores
Santos, Ronaldo Junior dos [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Neste trabalho foram investigadas as propriedades tribológicas e mecânicas de um filme de carbono amorfo hidrogenado (a-C:H) na superfície de uma liga de aço 16MnCr5. Filmes de a-C:H foram aplicados com o objetivo de aumentar a dureza superficial e reduzir o coeficiente de atrito entre superfícies de elementos de motores. As amostras foram obtidas a partir do aço liga 16 MnCr5, através de tiras metálicas. Os sustratos foram inicialmente limpos por um processo de lichamento, lavagem e subseqüentemente por um procedimento a plasma. Os filmes foram então depositados utilizando-se plasmas de baixas temperaturas de misturas de hidrocarbonetos e gases nobres. Foi utilizada a técnica híbrida de implantação iônica e deposição por imersão em plasma (IIDIP), aplicando-se pulsos de alta tensão negativa às amostras para promover a deposição mediante à implantação iônica. Neste caso, o metano (CH4) diluído em argônio foi utilizado como mistura precursora da formação do filme. Foi investigado o efeito da ampliação dos pulsos de polarização, da proporção de metano e do tempo de implantação nas propriedades dos filmes. As espectroscopia de infravermelho e Raman foram empregadas para se avaliar a composição química e a microestrutura dos filmes. A análise dos espectros Raman associada às análises do módulo de elasticidade e coeficiente de atrito apresenta características de filmes com teores de hidrogênio em torno de 20%. A molhabilidade dos filmes foi determinada pela técnica de ângulo de contato utilizando-se água deionizada como líquido de prova. De uma forma geral, os resultados revelaram que os filmes são levemente receptivos à agua e tal fenômeno da superfície foi determinado por perfilometria e microscopia de força atômica (AFM), enquanto a morfologia superficial das superfícies foi investigada...
This work investigated the tribological and mechanical properties produced by a film of hydrogenated amorphous carbon (a-C:H) on the surface of an alloy steel 16MnCr5. The a-C:H films were applied to increase the surface hardness and reduce the coefficient of friction between surfaces of engine components. The samples were obtained from alloy steel 16 MnCr5 through metallic strips. The substrates were initially creaned in a process of sanding and washing and subsequently in a plasma processing. The films were made using low temperature plasmas of hydrocarbons and noble gas mixtures. The plasma immersion ion implantation and deposition (IDIP), was used, applying high negative voltage pulses to the samples to promote deposition by ion bombardment. Methane (CH4) dilluted in argon was used as the gas mixture for film formation. The effects of the pulse magnitude, the proportion of methane and deployment time on the properties of the films were employed to evaluate the films chemical composition and microstructure. The analysis of the Raman spectra along with the elastic modulus and coefficient of friction indicates a films with a hydrogen content of aroud 20%. The receptivity of the films to water was analyzed by contact angle (Θ) measurements which revealed a moderated affinity to water (Θ~80º) as a consequence of a low concentrations of polar groups on the film surface. The surface topography was determined by perfilometry and atomic force microscopy (AFM), while the surface morphology was investigated by scanning electron microscopy (SEM), respectively. The roughness did not vary greatly among the samples. The hardness of the samples was measured by nanoindentation, varying between 13 and 21 GPa that are characteristic of plasma deposited a-C:H. It was found that films prepared with higher proportions of methane and higher deposition times presented... (Complete abstract click electronic access below)
This work investigated the tribological and mechanical properties produced by a film of hydrogenated amorphous carbon (a-C:H) on the surface of an alloy steel 16MnCr5. The a-C:H films were applied to increase the surface hardness and reduce the coefficient of friction between surfaces of engine components. The samples were obtained from alloy steel 16 MnCr5 through metallic strips. The substrates were initially creaned in a process of sanding and washing and subsequently in a plasma processing. The films were made using low temperature plasmas of hydrocarbons and noble gas mixtures. The plasma immersion ion implantation and deposition (IDIP), was used, applying high negative voltage pulses to the samples to promote deposition by ion bombardment. Methane (CH4) dilluted in argon was used as the gas mixture for film formation. The effects of the pulse magnitude, the proportion of methane and deployment time on the properties of the films were employed to evaluate the films chemical composition and microstructure. The analysis of the Raman spectra along with the elastic modulus and coefficient of friction indicates a films with a hydrogen content of aroud 20%. The receptivity of the films to water was analyzed by contact angle (Θ) measurements which revealed a moderated affinity to water (Θ~80º) as a consequence of a low concentrations of polar groups on the film surface. The surface topography was determined by perfilometry and atomic force microscopy (AFM), while the surface morphology was investigated by scanning electron microscopy (SEM), respectively. The roughness did not vary greatly among the samples. The hardness of the samples was measured by nanoindentation, varying between 13 and 21 GPa that are characteristic of plasma deposited a-C:H. It was found that films prepared with higher proportions of methane and higher deposition times presented... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Filmes finos, Ciência dos materiais
Como citar
SANTOS, Ronaldo Junior dos. Síntese de filmes finos a-C:H pela técnica de implantação e deposição por imersão em plasma. 2011. 122 f. Dissertação (mestrado) - Universidade Estadual Paulista, Campus Experimental de Sorocaba/Iperó, 2011.