Advanced Materials Research Vols. 97-101

Abstract: The aim of the present work is to obtain iron-oxide coated porous ceramics filter (IOCPCF) via dip-coating and test its adsorption and degradation for methylene blue (MB). Porous ceramics filter (PCF) and ferric nitrate were used as substrate and modifier respectively. IOCPCF was characterized by spectrophotometer, X-ray diffraction, scanning electron microscopy, specific analyzer and Fourier transform infrared spectroscopy. The effect of its structure and performance on adsorption and degradation of MB aqueous solution was investigated. The results indicated that the average pore diameter, specific surface area and porosity of IOCPCF were 11.36 nm, 4.987 m2/g and 58.63% respectively. The major crystalline phase of iron coat was α-Fe2O3 which took on porous framework. Using the prepared material, the decoloration conversion for MB aqueous solution can reach 72.06% in 300min and be increased by 21.59% compared with original PCF.

Abstract: Co-Ni coated ZrO2 composite powder was prepared by an optimized ultrasonic electroless plating process to obtain good microwave absorption properties in GHz region. Aggradation mechanism of electroless Co-Ni alloy was analyzed and the principal influencing factors on the depositing rate were investigated by weighting-in-powder. The metallized powder was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and vector network analyzer. Results showed that ultrafine ZrO2 powder pretreated with sensitization and activation were homogeneously deposited with Co-Ni coating at 358K and pH value of 9, immerged in the optimal plating bath using NaH2PO2 as reductant. The Co-Ni coating deposited in the alkaline plating bath had the depositing rate of above 6µm/h and the average weight ratio of 5.5 for Co/Ni. The new metallized powder was endowed high microwave absorbing properties; the maximum reflection loss reaches to -23dB at the frequency of 9.40 GHz.

Abstract: The surface composite layer Ni/WC on the cast iron substrate was fabricated through vacuum infiltration casting technique using Ni-based powder and WC particles with different content as raw materials. The micro-structure of infiltrated layer was compact for all infiltrated layer with different WC content, and WC particles distributed uniformly. The surface infiltrated layer was mainly composed of WC particle, intermetallic compound and solid solution. The thermal cycles were beyond 108 times when the infiltrated layer peeled off, which indicated that the specimen with infiltrated layer offered excellent thermal fatigue property. The oxidation rate of substrate was nearly three times as large as that of the infiltrated layer with 20% WC content. The oxidation resistance of the infiltrated layer improved obviously comparing with the substrate because the oxide layer for infiltrated layer was compact.

Abstract: The electropolymerizition of polyaniline (PANI) on Pb substrate was performed by potentiostatic or galvanostatic method in aniline＋oxalic acid electrolyte. The PANI coatings were characterized by FTIR, XRD and SEM methods. The results showed that the PANI coatings have a crystalline-amorphous composite structure whose degree of crystallinity is about 30%~50%. They belong to a conducting emeraldine salt form and contain varied amounts of water (hydrated PANI salt). The PANI coating synthesized at low current density is in a more reduced state. There is a fibrillar-like morphology for the PANI coatings electrodeposited on Pb substrate.

Abstract: The movements of liquids in the jet area, the transient area and the atomization area were analyzed in a high voltage electrostatic field and the parenchyma of charged liquid drops atomization in these areas were discussed. Experimental equipment, by which the high voltage electrostatic field can be built, has been designed, and the atomization processes of kerosene, emulsifier and alcohol in a high voltage electrostatic field have been studied. The results show that a threshold voltage is needed in order to break up the liquid drops. The lower surface tension and the lower viscous force of liquid, and the higher electrical conductivity ratio, correspond with better electrostatic atomization effects. For kerosene, emulsifier and alcohol, the best atomization effects have been achieved at 40kV, 10kV and 25kV respectively.

Abstract: The paper discusses the major manufacturing processes of vehicle wheels and the current load-unload situation, analyses the structural shape of vehicle wheels, and designs the vehicle wheel gripper. Also the paper studies the image acquisition, image processing and automatic recognition based on the vehicle wheel manufacturing.

Abstract: Ni-W-P-CeO2-SiO2 nanocomposites were pulse electrodeposited from the bath containing suspension of nano-sized CeO2 and SiO2 particles. The influence of heat treatment temperature on the structures and properties were studied. The phase structures, surface morphologies, microhardness and oxidation behavior were evaluated by XRD, SEM, microhardness and oxidation weight gain test. Additionally, the sequence of phase transformation of the nanocomposites was found to be as follows: amorphous phase→intermediate metastable→stable alloy phase. Nano-particles co-deposited into Ni-W-P alloy can inhabit the grains growth, increase microhadness and high temperature oxidation resistance during the course of heat treatment.

Abstract: The microstructure and properties of ternary boride ceramic coating prepared by reactive flame spraying on surface of H13 steel are studied as well as the microstructures, microhardness, wear resistance and thermal fatigue resistance of the coating. The results show that the Mo2FeB2 cermet coating by reactive flame spraying has good wear resistance and thermal fatigue resistance and its microhardness can even reach 1200 HV.

Abstract: The thin film can improve the surface performance of rolling bearings to reduce friction, vibration and noise and to increase the operating life of rolling bearings. This paper proposes a novel method for improving the surface performance of rolling bearings. This method is characterized by adding nanoparticles to the superfinishing liquid to form the nanofilm on the surface of the raceway by means of the special superfinishing technique. The experimental investigation proves that using this method, the fatigue life of the rolling bearing is obviously higher than that of the normal bearing. Surface topography photos of the Scanning Electron Microscope show that the thin film still exists after the fatigue test in 300 hours. Because of low cost, this method can be widely used in the production of rolling bearings.

Abstract: The invention of functionally graded structure cemented carbide is a significant revolution. In this paper, graded structure cemented carbide with cubic carbide free layer (CCFL) was prepared. Using scanning electron microscope (SEM), metallographical microscope, electroprobe microanalyzer and microindentation, the gradient characteristics were investigated. The variation in elemental compositions from surface to inner is gradient, the concentrations of nitrogen and titanium are very low in surface layer, only element of tungsten, cobalt and carbon exist. A cobalt concentration peak occurs, which is higher than the average composition in bulk. Wherein binder phase piles up, its volume fraction is much higher than nominal value, resulting in a decrease in hardness and forming a tough layer.