Papers by Author: Bai Yang Lou

Abstract: In vitriolic electrolyte, DC power supply is used on 7075 aluminum alloy to have anodic oxidation treatment then let the oxidized samples have a treatment of electroless plating. Surface morphology of the coating and performance of corrosion wear are studied by means of scanning electron microscope (SEM) and friction and wear experimental machine. The results show that unsealed oxide coating have many holes and cracks, which are extremely badly-distributed; corrosion resistance of the oxide coatings which have the treatment of electroless plating have improved, having lower coefficient of friction and better performance of corrosion wear; besides; coefficient of friction of the samples in water is higher than that in salt water, its wear amount is less.

Abstract: The Pd/Sn catalytic coating on graphite electrode had been synthesized by chemical plating in this paper. Scanning electron microscope(SEM)and Electrochemical workstation(EW)were used to analyze the coating surface topography and electro-catalytic properties of modified graphite electrode with and without the coating. Results show that Pd and Sn are in the form of spherical particle and completely cover the surface of graphite electrode includes concave defects. Most Pd and Sn particles are dispersive ones of size of about 70 nm and few of which are polymerized in island forms. The peak value of current density increases with scanning speed, which goes positive potential scanning. Further more, the peak current increases with the concentration of NaOH solution, which shows nonlinear relationship between peak current and solution concentration, The peak current increases more rapidly with solution concentration increases in low NaOH concentration solution than that in high NaOH concentration solution.

Abstract: Nano copper /paraffin thermo sensitive composite was prepared by high energy milling and pressed into a glass cylindrical tube by using thermoforming process. Thermo sensitivity of the thermo sensitive composite was tested by thermo sensitivity tester which is developed by us. The composite particles with good cladding effects, prepared by high energy milling, arrange close together. Copper particles have no damage on the structures of paraffin. The thermal conductivity of thermo sensitive composite is enhanced with the increase of mass ratio of copper powder.

Abstract: In this paper, nano-copper/paraffin thermosensitive composite materials were prepared by high-energy ball milling, and pressed into the glass cylindrical tube by hot press molding. The micro-morphology and particle shape and microstructure of composite particles were observed by SEM, FI-IR, etc, the temperature sensibility of thermosensitive composite materials were tested by self-manufactured thermosensitive testing device. It shows that the way by which high-energy ball milling are prepared, the composite particle coated with good results, dense arrangement of particles, copper particles on the paraffin structure does not produce damage. With copper mass ratio increasing, the thermal conductivity of temperature sensitive composite is improved.

Abstract: Solution polymerization method was used to prepare hydrophilic antifogging acrylate resin. By means of comparison, the optimum synthesis technology conditions was obtained that ethyl acrylate was used as soft monomer , methylcrylate was used as hard monomer. The best functional monomers was acrylic acid and methyl acrylic acid. The accessory functional monoer was β-hydroxyl ethyl acrylate. Cross-linking agent methylol acrylamide belongs to self-cross-linking system. Crosslinker was N-hydroxymethyl acrylamide.The quality rate of cross-linking agent and carboxylic acid is 4 to 1 .The resin can be cured perfectly at the temperature of 100°C in 40 min. The prepared acrylate resin had excellent water-solubility and antifogging.

Abstract: Magnesium alloys were treated by micro-arc oxidation at a constant applied current density. The friction and wear properties were investigated by optical microscope and universal friction and wear tester in 3.5%NaCl solution. The result reveals that the film formed by micro-arc oxidation enhances the corrosion resistance of the magnesium alloys. The Ecorr of micro-arc oxidation film improved 94mV than the Ecorr of magnesium alloys matrix. Wear resistance of the film was weakened in 3.5%NaCl solution. The wear mechanism of film depends on the load. Abrasive wear was predominant at low load. Peeling wear was predominant at high load, which result from damage of the film adhesion.

Abstract: The numerical simulations of mold filling and solidification process for the A380 aluminum alloy were done by the supposed mathematical model. The casting defects in the process of mold filling and solidification were predicted by the result of the casting simulation. The casting defects of simulation are well compared with the practice. Some measures presented were improved for the existing technological process.

Abstract: This paper introduces electroless plating Ni-Cr-P/Ni-P composite coating technologies and techniques on the Nd-Fe-B permanent magnet surface. It has got a Ni-Cr-P/Ni-P composite coating successfully on the Nd-Fe-B substrate surface through rational processing plan. The coating surfaces are bright and have low Porosity, good binding between the electroless plating and Nd-Fe-B matrix. The experimental results show that the composite coating prepared by Ni-Cr-P electroless plating (15min) and Ni-P acidic electroless plating (45min) has amorphous structure, simple process and better anticorrosion property in both alkaline and acidic medium.

Abstract: Using an alternative pulse current source and in silicate solution electrolyte，a uniform coating on the surface of AZ9lD alloy was fabricated by micro-arc oxidation(MAO) with current density of 40mA/cm2. Friction wear testing machine was used to study the wear behavior under corrosive environment of the film and scanning electron microscopy(SEM)were used to study microstructures of film and worn surface．The result shows that the corrosion resistance of micro-arc oxidation film is large better than that of magnesium alloy. The corrosive solution great weaken the abrasion resistance of the coating. As the influence of the corrosive solution, the wearing mechanism is varying with the loading. Abrasive wear is the main mechanism when the loading is small, if the loading is large enough, the binding force will be destroyed and the coating will peel off from magnesium alloy.

Abstract: The modification of Nano Pt and carbon black compound coating on the fuel cell’s graphite electrode by the method of vacuum ion plating and ethanol catalytic combustion. The microstructures and the electro catalysis properties of the electrode surface before and after the modification were analyzed and tested with the methods of scanning electron microscope(SEM), transmission electron microscope(TEM), electrochemical workstation and so on. The effects of nano Pt and carbon black on the electrode’s electro catalysis properties were investigated. The Study results have shown that carrying on electrochemical properties test to the graphite electrode which has been treated with nano Pt and carbon black compound surface modification, there will be three oxidation peaks in its cyclic voltammograms and the background current will be higher. Compared with the nano Pt surface modification, the electrode which has been treated with nano Pt and carbon black compound surface modification has better ethanol electro catalysis properties. The high specific surface area acquired from the nano carbon black surface modification and the synergic action of the catalytic material Pt can improve the ethanol electro catalysis properties of the electrode effectively.