title: Electrodeposition of nanocrystalline Ni-W coatings with citric acid system.
abstract: Ni-W alloy coatings were prepared by electrodeposition technique with citric acid as a complexing agent. The influence of the main technical parameters on W content in the Ni-W alloy coatings were investigated by electron dispersive spectroscopy (EDS), and the microstructure of the coatings was characterized and analyzed by employing X-ray diffractometer (XRD), scanning electron microscope (SEM). The results showed that bright and compact Ni-W alloy coatings with 25.78 wt% W were obtained when the concentration of Na2WO4 x 2H2O was 50 g/L, the concentration of NH4Cl was 20 g/L, the bath pH value was 8.0 and the bath temperature was 70 degrees C. The surface of Ni-W alloy coatings were bright, flat and compact, the mircostructure of the alloy coatings were nanocrystalline and the average grain size was about 38 nm by calculating using Scherrer Equation.
authors: School of Metallurgical Science and Engineering, Central South University, Changsha 410083, P. R. China.
authors: Jingjing
authors: J
authors: Du
authors: Lijian
authors: L
authors: Xu
authors: Baizhen
authors: B
authors: Chen
authors: Li
authors: L
authors: De
mesh_terms: D000327:Adsorption; D000497:Alloys / Q000737:chemistry; D019343:Citric Acid / Q000737:chemistry*; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D004595:Electroplating / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008956:Models, Chemical; D008968:Molecular Conformation; D009532:Nickel / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties; D014414:Tungsten / Q000737:chemistry*
chemical_list: D000497:Alloys; D046911:Macromolecular Substances; D019343:Citric Acid; D009532:Nickel; D014414:Tungsten