Akademik Veri Yönetim Sistemi
Tezin Türü: Doktora
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Metalurji ve Malzeme Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2013
Öğrenci: EBRU SARALOĞLU GÜLER
Danışman: İSHAK KARAKAYA
Özet:The influence of the electroplating parameters and their interactions on hydrogen evolution reaction (HER) and the internal stress were studied during the electrodeposition of Ni and Ni-MoS2 composite coatings by fractional factorial design (FFD) and analyzed by Minitab software package. The parameters and their ranges were; MoS2 particle concentration (0 and 30 g/L), temperature (30 and 50 ºC), pH (2 and 4) and three surfactants, sodiumlignosulfonate (SLS), ammoniumlignosulfonate (ALS) and depramin-C (DC) (0 and 1 g/L), for voltammetric measurements of HER. The internal stress during electrodeposition was measured by deposit stress analyzer. The MoS2 particle concentration (0 and 10 g/L), temperature (30 and 50ºC), pH (2 and 4), current density (1.2 and 4.8 A/dm2) and coating thickness (25 and 50µm) were the parameters. The best combination of parameters (temperature: 50ºC, pH: 2, current density: 4.8 A/dm2, thickness: 50 µm, in presence of MoS2) for the lowest internal stress was determined. Meanwhile, the effects of mineral processing surfactants (SLS, ALS and DC) on homogeneity of MoS2 particles and on internal stress were investigated. Since relatively more homogenous particle distribution was observed when SLS was added, it was used in the experiments. The tribological behavior of Ni-MoS2 composite coatings developed under above mentioned conditions were studied by using a pin–on-disc tribometer. The effects of MoS2 particle concentration (5, 10 and 30 g/L), MoS2 particle size (1.440 and 5.156 µm average) and the surfactant (SLS) amount (0.3 and 1 g/L) on the friction and wear behaviour were investigated. Small particle size, high MoS2 and surfactant amount decreased the friction coefficient.