مشخصه يابي پوشش هاي نانو كامپوزيتي Ni-SiC-CNT توليد شده به روش آبكاري الكتريكي

چكيده انگليسي :

Characterization of Ni SiC CNT nanocomposite coationgs produced by electroplating technique Mohammad Hossein Mosallanejad mh mosallanejad@ma iut ac ir Date of Submission 2014 1 11 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Ali Shafyei shafyei@cc iut ac irAbstractThe surface of a material or component might be deemed because of its atomic structure to be the mostvulnerable site for various forms of attack Therefore it is necessary to take required actions in order toprotect the surface of the components which is done in different ways Electroplating method due to lowerproduction costs ease of production and ease of process control is of paramount importance Many studieshave been performed on the production of Ni electroplated coatings In this respect the use of silicon carbideparticles as a reinforcing agent in nickel coating has attracted the attentions In order to improve thetribological properties of the coating carbon the graphite or carbon nanotubes have also been used In mostof the researches CNT and SiC have separately been used in nickel coating In this study The Ni SiCcomposite coatings at three different concentrations of 5 10 and 15 g l of reinforcing particles were producedusing an electroplating process onto an aluminum substrate After finding the best sample consideringresistance to wearing impact of carbon nanotubes at a concentration of 2 and 6 g L as strengthening agentalong with SiC particles were investigated Nano hardness and wear resistance of the samples wereexamined Surface and section of the Coatings and also wear scratches were examined using SEM In orderto investigate the effect of current density on the surface roughness morphology of the substrate and nickelcoatings at two different current densities of 3 A dm2 and 6 A dm2 were evaluated using AFM Increasing thecurrent density parameter from 3 A dm2 to 6 A dm2 did not cause a significant change in Ra parameter onlythe overall shape of the surface topography changed Increasing the concentration of SiC particles in theelectrodeposition bath from 5 g l sample S5 to 10 g l sample S10 led to improved wear properties of thecoating The presence of carbon nanotubes on the surface of the coatings led to an increase in the co deposition of SiC particles from 17 64 vol in S10 sample the sample produced in a 10 g l SiC bath to20 27 vol in SC6 sample the sample produced in a 10 g l SiC and 6 g l SiC bath also CNT disturbed thedistribution of SiC particles in the coating Using CNT up to a certain extent along with SiC led to improvedhardness and wear resistance of Ni SiC coating increasing CNT up to 6 g l increased the hardness of S10sample from 451 Vickers to 508 Vickers in SC6 sample and also increased the elastic modulus from 145 49GPa in S10 sample to 169 67 GPa in SC6 sample Mass loss of SC6 sample was improved by 41 6 afterwear test in comparison with S10 Key words nanocomposite coating Electroplating Nickel Carbon nano tube nanohardness

مصلي نژاد، محمدحسين

مشخصه يابي پوشش هاي نانو كامپوزيتي Ni-SiC-CNT توليد شده به روش آبكاري الكتريكي

نيكل , نانو لوله كربني , نانو سختي