Eventos Anais de eventos
COBEF 2017
Congresso Brasileiro de Engenharia de Fabricação
EFFECT OF CARBON NANOTUBE LOADING ON THE CORROSION BEHAVIOR AND HARDNESS OF Ni-P-CARBON NANOTUBE COMPOSITE COATINGS OBTAINED BY AUTOCATALYTIC DEPOSITION ON API 5L X80 PIPELINE STEEL
Submission Author:
Laís Bertunes , SP
Presenter: Laís Bertunes
doi://10.26678/ABCM.COBEF2017.COF2017-1071
Abstract
Carbon nanotubes (CNTs) are attractive materials due to an impressive combination of properties such as high thermal and electrical conductivities and excellent mechanical strength. Composite coatings containing CNTs as reinforcing particles can be used as protective layers against wear and corrosion of machinery parts. The surface properties of Ni-P films deposited by electroless plating can be optimized by incorporating CNTs. The aim of the present work was to incorporate multiwalled carbon nanotubes (MWCNTs) into Ni-P coatings obtained by electroless deposition on API 5L X80. Additionally, the effect of MWCNT concentration on the corrosion resistance of the deposited films was investigated. Film morphology was evaluated by scanning electron microscopy. Differential scanning calorimetry and x-ray diffraction were used to characterize the film structure. The electrochemical behavior of the composite layers was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization. The as-deposited films presented broad diffraction peaks related to the Ni-P matrix, indicating its amorphous character. The presence of MWCNTs did not influence the DSC curves with respect to conventional Ni-P coatings. Film morphology was influenced by the MWCNTs, showing a decrease of metal nodules as the nanometric filler concentration increased. As a result, the corrosion behavior was affected as well. For higher filler loadings, the corrosion resistance increased due to the more compact surface morphology.
Keywords
Ni-P-carbon nanotube coating, electroless deposition, corrosion, API 5L X80 pipeline steel
