Li Jiang

Bio: Li Jiang is an academic researcher from China Jiliang University. The author has contributed to research in topics: Crystallite & Ionic liquid. The author has an hindex of 1, co-authored 1 publications receiving 7 citations.

Electrodeposition of Al-Mn-Zr ternary alloy films from the Lewis acidic aluminum chloride-1-ethyl-3-methylimidazolium chloride ionic liquid and their corrosion properties

Abstract: The electrodeposition of Al-Mn and Al-Mn-Zr alloy films on low carbon steel substrate from the Lewis acidic aluminum chloride-1-ethyl-3-methylimidazolium chloride (AlCl 3 /[Emim]Cl) ionic liquids with different metal salts is investigated. The addition of ZrCl 4 in the bath with 0.04M MnCl 2 induces the higher overpotential for the electrodeposition, which decreases the size of the electrodeposited primary crystallites. Rounded nodular particles composed of many primary nanocrystallites are obtained by the electrodeposition in the bath containing 0.04 M MnCl 2 and 5 mM ZrCl 4 . The close packing of these nodular particles results in the formation of the Al-Mn-Zr ternary alloy film with a dense structure. Compared with the bare carbon steel electrode, the as-electrodeposited Al-Mn and Al-Mn-Zr alloy film electrodes shows much more negative corrosion potentials, indicating their cathodic protection effect on the substrate. As the Zr content in the alloy films becomes larger, the corrosion current density first decreases, and then increases. The Al-Mn-Zr ternary alloy film with 1.871 at.% Zr, which is prepared in the bath with 0.04 M MnCl 2 and 5 mM ZrCl 4 , manifests the lowest corrosion current density. This can be attributed to its dense film structure and good combination with the substrate.

Template-free preparation of spherical Al particles in aluminum chloride and 1-butyl-3-methylimidazolium chloride ionic liquid

Abstract: A template-free electrochemical deposition method for preparation of spherical-like Al particles in the aluminum chloride and 1-butyl-3-methylimidazolium chloride (AlCl3–[Bmim]Cl) system was reported in this work. Effects of current density, electrodeposition time, and temperature on surface morphologies of Al deposits were studied. Results showed that Al particles displayed uniform spherical-like morphology with the diameter range of 5–40 μm. Al particles presented irregular pie shaped with sizes ranged from 70 to 80 μm at low current densities of 2 and 10 mAcm−2. When the current density increased from 20 to 40 mAcm−2, particles tended to be spherical-like with sizes ranged from 10 to 20 μm. The particle size of deposits decreased with increasing current density on the same total amount of electric charges of 200 C due to the more compact arrangement of particles at high current density. The highest current efficiency reached at about 94%. Al particles were prepared at the current density of 40 mAcm−2 for a period time of 1000 s, 50 °C. The results of EDS analysis showed that the contents of the deposition were oxygen 5.79 wt.% and aluminum 94.21 wt.%. Almost spherical electrodeposition products about 50 g composed with pure metallic Al were obtained successfully in an amplified experiment finally.

Progress on Electrodeposition of Metals and Alloys Using Ionic Liquids as Electrolytes

Abstract: The electrodeposition process of metals and their alloys is widely used in the automotive, space, electronics, computing, jewelry, and other consumer items industries. Over the years, the search for new coatings with more suitable characteristics for their application led to the use of ionic liquids (ILs) as electrolytic solutions. In addition to having good conductive properties, the growing interest in these solvents has environmental appeal due to their low toxicity. Furthermore, the ability of these electrolytes to dissolve compounds containing less soluble metals makes them potential substitutes for environmentally harmful solvents. In this sense, this review describes the current state and the innovations concerning the electrodeposition of metals and alloys using ILs as electrolytes in the last five years. Metals were classified into five groups (common, light, noble, rare earth, and others), highlighting not only the ability to form a smooth, homogeneous, and anti-corrosive deposit, but also the reactive capacity of metals in hydrogen evolution and catalytic processes.

Structure property correlation of electro-codeposited Cu-Al-V2O5 composite coating obtained from Al-V2O5 dispersed electrolyte

Abstract: The present work depicts electro-codeposition of copper along with Al (size ~ 20 nm) and V2O5 (size ~ 350 nm) particles as second phase reinforcements on copper substrate. Different compositions of Cu-Al-V2O5 composite coatings were formed from acidic electrolyte with addition of 5 g/l Al and 10 g/l V2O5 particles in the deposition bath with 8 A/dm2 current density both in the presence and absence of CTAB. Field emission scanning electron microscope (FESEM) image of non-CTAB added coatings show coarser structure compared to CTAB added coatings. Mechanical characterizations of the coatings portray better hardness and wear resistance of composite coatings compared to unreinforced Cu coated sample. Among the non-CTAB and CTAB assisted coatings, CTAB treated specimens have better mechanical properties in terms of hardness and wear resistance compared to non-CTAB ones due to finer coating matrix and formation of (220) texture. The downgrading of electrical conductivity values of the composite coatings was due to the codeposition of insulating V2O5 and finer coating matrix. Aluminum in the coating tends to maintain the electrical conductivity but provides little strengthening effect.

Molten salt electrodeposition of aluminum on mild steel: effect of process parameters on surface morphology and corrosion properties

Abstract: The electrodeposition of aluminum on mild steel in a molten salt electrolyte consisting of a mixture of AlCl3/NaCl/KCl (weight percent ratio of 80:10:10) was studied. Parametric studies were carried out to evaluate the effect of different parameters such as current density, electrolysis time, and intermediate coating layer on the coating morphology and coating-to-substrate adhesion. The quality and morphology of the coating were investigated using scanning electron microscope (SEM) and x-ray map analyses. The effect of heat treatment of the coated samples on the interface stability and formation of intermetallic compounds at the Al-Fe interface was also investigated. Cross-sectional examination by SEM as well as energy dispersive spectroscopy (EDS) line scan showed that upon annealing at temperatures in the range of 350 °C–550 °C, brittle Fe-Al intermetallic layers were formed at the interface. This shows that high-temperature service conditions can adversely affect the coating properties. The apparent activation energy of the formation of such intermetallic layers was calculated based on thickness measurements on these layers. The optimum conditions for electroplating were determined as current density of 0.022 A.cm−2 and electroplating time of 60 min. Potentiodynamic polarization tests were used to evaluate the corrosion resistance of the samples in 3.5 wt% NaCl solution. Considering the corrosion rate of coated samples which is much lower than the bare substrate, it was concluded that the electrodeposited coatings could efficiently protect the steel substrate against corrosion in corrosive media.