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Nanoparticle magnesium borate with a particle size of about 10 nm was prepared using ethanol supercritical fluid drying technique and was characterized with TEM, XRD and X-ray small angle scattering. Tribological properties of the nanoparticle magnesium borate, using as lubricating oil additive, were evaluated using a four-ball and a block-on-ring tribotester. The wear scar was characterized with SEM and XPS. Results indicate that the wear resistance and load carrying capacity of the 500 SN base oil were improved and the friction coefficient of the oil was decreased by the additive. FeB were formed on sliding surface.

Nanoparticle amorphous lanthanum borate with a particle size of 20–40 nm was prepared with a Replacing Solvent Dry technique and characterized using TEM and XRD. Its tribological properties as a wear resistance additive of lubricating oil were evaluated with a four-ball tribotester. The wear scar was characterized with XPS. The wear resistance and load carrying capacity of 500 SN base oil was improved by the lanthanum borate. Diboron trioxide and FeB were formed on the wear scar surface. These tribochemical reaction products as well as some depositions formed a wear resistance film on the rubbing surface, which provided the oil with an excellent load carrying capacity.

An oil-soluble compound containing ferrous iron and boron–ferrous octoxyborate was synthesized. The antiwear and friction-reducing properties of the compound as a lubricating oil additive were evaluated using a four-ball and a block-on-ring tribotester. Results indicated that both the wear resistance and the load-carrying capacity of a 500 SN base oil were improved and its friction coefficient was decreased by the additive. The wear scar, after being cleaned using an ultrasonic bath in ligroin and in distilled water, was characterized with SEM and XPS. Diboron trioxide, FeB and Fe2B were all found to have been deposited on the wear-scar surface. It was this deposition that provided the oil with excellent antiwear and friction-reducing properties.

Amorphous ferric oxide with a particle size of about 20–50 nm was prepared using the ethanol supercritical fluid drying technique. The tribological properties of 500 SN oil containing nanometer particles were measured using four-ball and block-on-ring tribotesters. Results indicated that the wear resistance and load-carrying capacity of the oil was raised and its friction coefficient was decreased. Excessive nanometer additive was disadvantageous for the load-carrying capacity of lubricating oil. The dispersing agent played an important role in the improvement of the tribological properties, and copper stearate was markedly superior to sorbitol monostearate. Nanometer ferric oxide took effect by its deposition on the rubbing surface.

Nanometer crystal titanium oxide with a particle size of about 20 nm was prepared using ethanol supercritical fluid drying technique. Tribology properties of 500 SN oil with the nanometer particles were measured using four-ball and block-on-ring tribotester. Results indicated that wear resistance and load carrying capacity of 500 SN base oil were improved and friction coefficient was decreased by an addition of the nanometer particles. There was an optimal content of titanium oxide in the oil, which gave the highest maximum nonseized load. Nanometer titanium oxide took effect by its deposition on rubbing surface.

SUMMARYThe electrodeposition of Ni-W alloy has been studied on the glassy carbon electrode by the cyclic voltammetry and potentiostatic step methods. It has been found that electrodeposition of Ni-W alloy involves an intermediate valence tungsten oxide which inhibits hydrogen evolution. Ni-W alloy electrodeposition occurs by a mechanism involving progressive nucleation followed by three dimensional growth.The structures of nickel-tungsten alloy deposits were analyzed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The XRD results from Ni-W alloy deposits reveal a face-centered cubic solid solution, the microstructure of the deposits exhibit (111) preferred orientation. The lattice constant and microhardness of Ni-W alloy deposit increase as the tungsten content increases, the XPS results of Ni-W alloy deposits indicate that the nickel and tungsten of the deposits exist in the metallic state, but the Ni-W alloy deposit with a tungsten content of 40.7% is an intermetallic compound. Th...