Nowadays, application of nanocrystalline nickel-tungsten (Ni-W) alloys is receiving a great interest because they are an efficient replacement for hard chromium coatings owing to their premium hardness, wear, and corrosion properties. Moreover, heat-treated nanocrystalline Ni-W alloys demonstrate proper mechanical properties as well as thermal stability at high temperatures. The current paper reviews different aspects of electrodeposition, microstructure, corrosion, oxidation, wear, and mechanical properties Ni-W alloys and nano/micro composites. Besides, heat treatment effects on properties and thermal stability of these alloys are also reviewed.

Ni-W electrodeposited coatings: Characterization, properties and applications

Recovery of indium from LCD screens of discarded cell phones.

Recovery of indium from liquid crystal displays

The mineralogy and mineral chemistry of indium in sulphide deposits and implications for mineral processing

Improved dielectric and non-ohmic properties of (Zn + Zr) codoped CaCu3Ti4O12 thin films

The effect of sintering processes, such as open sintering, sintering inside a closed crucible, and sintering within a powder bed, on the microstructure and V–I characteristics of ZnO–Bi2O3-based varistor ceramics was investigated at sintering temperatures in the range 1000–1200 °C. The results from the experiments showed that the microstructure and electrical properties of the samples varied according to the sintering method and temperature. Optimal values for the electrical characteristics of the varistor ceramics by different sintering processes were obtained when the sintering was conducted at 1100 °C. At the same sintering temperature, the different processes affected the properties differently. At 1000 °C, the samples sintered within a powdered bed showed better electrical properties than those subjected to the other two processes, while at 1100 or 1200 °C, the samples sintered in an open crucible exhibited the best electrical properties.

Microstructure and electrical properties of ZnO–Bi2O3-based varistor ceramics by different sintering processes

Preparation of Ni–W–SiO2 nanocomposite coating and evaluation of its hardness and corrosion resistance

Ti5Si3 silicide has been extracted directly from complex multicomponent Ti/Si-containing metal oxide compounds by electro-deoxidation in molten calcium chloride using an inert solid oxide oxygen-ion-conducting membrane (SOM) based anode. Studies on the microstructure evolution and electrochemical extraction mechanism show that the formation of Ti5Si3 and the removal of impurity elements happened simultaneously during the electro-deoxidation process. It is found that the electro-deoxidation generated Ti5Si3 micro-particles typically possess a smooth surface, which could contribute to create a continuous anti-oxidation surface layer with excellent high-temperature oxidation resistance property. Consideration is also given to the parameters of electrolysis and the electrochemical characteristics including chemical and/or electrochemical reactions during the electro-deoxidation process, and then a relevant kinetic model is proposed.

Electrochemical extraction of Ti5Si3 silicide from multicomponent Ti/Si-containing metal oxide compounds in molten salt

Precipitation of indium using sodium tripolyphosphate

The invention relates to an aluminum alloy surface phosphatizing fluid and a phosphatizing method, belonging to the technical field of processing of chemical conversion coatings on metal surfaces. The method of the invention mainly comprises the following steps: (1) determining the formula of the phosphatizing fluid, wherein the formula comprises the following components and contents: 4.0-8.0g/L of Zn , 15.0-30.0g/L of PO4 , 1.5-1.8g/L of F , 0.7-0.9g/L of Ni , 1.0-1.2g/L of ammonium molybdate, 0.4-0.8g/L of guanidine nitrate and 0.2-0.6g/L of salicylic acid; preparing the phosphatizing fluid from deionized water, and regulating the pH value of the phosphatizing fluid to 3.5-3.7 by 30wt% of NaOH solution; (2) grinding and polishing an aluminum alloy sheet, removing grease by acetone, etching the aluminum alloy sheet by 0.1mol/L of sodium hydroxide solution, soaking the aluminum alloy sheet into 5g/L of surface adjustment fluid to carry out surface adjustment for 1-2min, and then, putting the aluminum alloy sheet into the phosphatizing fluid; (3) controlling the temperature of the phosphatizing fluid at about 40 DEG C, and carrying out phosphatizing reaction for 5min; and (4) cleaning the aluminum alloy sheet by deionized water, and drying the aluminum alloy sheet by hot air. The phosphatizing film formed after phosphatizing has better corrosion resistance and is uniform and compact.

Qingdong Zhong

Papers

Microstructure and electrical properties of ZnO–Bi2O3-based varistor ceramics by different sintering processes

Preparation of Ni–W–SiO2 nanocomposite coating and evaluation of its hardness and corrosion resistance

Electrochemical extraction of Ti5Si3 silicide from multicomponent Ti/Si-containing metal oxide compounds in molten salt

Precipitation of indium using sodium tripolyphosphate

Aluminum alloy surface phosphatizing fluid and phosphatizing method