耐久性防酸防碱防水透湿涂层布的研究

介绍了耐久性防酸、防碱、防水透湿涂层布 ,并在工艺配方、工艺条件上采用共混改性技术 ,以提高聚丙烯酸酯涂层胶的抗酸碱性、透湿性 ,并就共混组分的相容性、共混体形态结构和共混比对产品性能的影响 ,进行了研究分析。

Effect of reagent films on coupling relationship between glass surface and particles

The experiments were conducted to investigate the behavior of airborne particles adhering to the glass slides which were coated by several reagent films. The results showed that the adhesion level could be significantly changed by the reagent films. There were no evident rules between the average size of particles and sampling time interval, the placing angle and reagent concentration. The average particle size on the surface coated by composite reagent （2-3 μm） was smaller than that on the single reagent coated surface, while the largest particle size （4-5 μm） was observed on the surface coated with the Tween 60. The experiment also demonstrated that the best adhesive performance was obtained on the surface which was coated with 0.5% SDBS and 0.5% fluorocarbon composite reagents. The experiment results indicated that each reagent had a certain optimum adhesive range to the particle. The composite reagents with different proportion of single reagents exhibited some particular physical and chemical properties, which could effectively change the adhesive performance between the solid surface and the particles.

A perspective of microplasma oxidation (MPO) and vapor deposition coatings in surface engineering of aluminum alloys

Over the past years, great achievements have been made in the development of coating technologies for surface improvement of aluminum alloys. Despite these achievements, the role in the market strongly depends on the ability of surface coating technology under technical and economic considerations to meet the increased demands for heavy tribological applications of aluminum alloys. Microplasma oxidation (MPO) technology has recently been studied as a novel and effective means to provide thick and hard ceramic coating with improved properties such as excellent load-bearing and wear resistance properties on aluminum alloys. The present work covers the evaluation of the performances of current single and duplex coatings combining MPO, physical vapor deposition (PVD), and plasma assisted chemical vapor deposition (PACVD) coatings on aluminum alloys. It suggests that the MPO coating is a promising candidate for design engineers to apply aluminum alloys to heavy load-bearing applications. The prospective future for the research on MPO coatings is introduced as well.

Effects of thickness and elastic modulus on stress condition of fatigue-resistant coating under rolling contact

The distribution and magnitude of surface substrates were investigated by finite element method and subsurface stresses of the （FEM）. The models of coating single-layer sprayed-coatings on monolithic configurations with different thicknesses and elastic modulus ratios of coating to substrate were introduced, and the effects of thickness and elastic modulus ratio on the stresses were addressed. The calculation results show that the coating/substrate interface shear stress obviously decreases with increasing coating thickness, due to the location of the maximum shear stress moving away from the coating/substrate interface. At the same time, the magnitude of von Mises stress also declines in the case of thicker coatings. However, the high elastic modulus ratio results in extremely high maximum shear stress and the severe discontinuity of the von Mises stress curves, which leads to the intensive stress concentration on the coating/substrate interface. So the coating configurations with the larger coating thickness and lower difference of elastic modulus between coating and substrate exhibit excellent resistant performance of rolling contact fatigue （RCF）.

歼7×飞机套罩选材设计改进的技术分析

本文分析了原蒙布材料053蒙布存在的问题，介绍了新材料656涤纶涂层布的主要性能和应用。

Coating of microbially produced calcium carbonate onto stone materials

The coatings of microorganism-induced calcium carbonate onto the stone surface carried out by using both of the immersion method and coating method were investigated. Various analysis and testing techniques such as scanning electron micrograph （SEM） and X-ray diffraction （XRD） were used to characterize the deposited mineral layer. The adhesive property, acid re- sistance, frost resistance, light and aging resistance, water adsorption and permeability were investigated in detail. The results showed that both immersion method and coating method could produce calcium carbonate granules with sizes ranging from 1 to 10 pm and form a layer of dense mineralization membrane which is about 50 to 100 pm thick. Immersion method was more efficient than coating method. The large cohesive force between calcium carbonate layer and stone materials could improve the acid rain resistance as well as excellent heat tolerance, frost resistance and light aging resistance. The coating process could not only help the stone materials maintain its original permeability with the aid of calcium carbonate layers but also improve the penetration resistance significantly. Therefore, this type of technology shows a great potential in the protection of stone relics.

Simulation of residual stresses and their effects on thermal barrier coating systems using finite element method

Thermal barrier coating(TBC)systems are widely used in industrial gas-turbine engines.However,premature failures have impaired the use of TBCs and cut down their lifetime,which requires a better understanding of their failure mechanisms.In the present study,experimental studies of isothermal cycling are firstly carried out with the observation and estimation of microstructures.According to the experimental results,a finite element model is established for the analysis of stress perpendicular to the TBC/BC interface.Detailed residual stress distributions in TBC are obtained to reflect the influence of mechanical properties,oxidation,and interfacial roughness.The calculated results show that the maximum tensile stress concentration appears at the peak of TBC and continues to increase with thermal cycles.Because of the microstructural characteristics of plasma-sprayed TBCs,cracks initialize in tensile stress concentration(TSC)regions at the peaks of TBC and propagate along the TBC/BC interface resulting in the spallation of TBC.Also,the inclusion of creep is crucial to failure prediction and is more important than the inclusion of sintering in the simulation.

Rapid nanopatterning technique based on monolayer silica nanosphere close-packing by spin coating

Nanoparticles monolayer formation by spin coating is considered to be a simple, fast and inexpensive nanopatteming technique However, the parameters that govern the overall growth process in this technique are not completely quantified and techniques for the controlled and continuous growth of close packed monolayer particle arrays without defects need to be developed. In this paper, an ordered particle array formation process is analyzed theoretically, employing material flux balance and parti- cle-subjected forces balance, based on the film thickness model of spin coating and evaporation rate law. A series of experi- ments were conducted using silica particle suspensions with various particle volume fractions and different spin speeds. The results show that the spin speed should match the particle volume fraction to meet the requirements of material flux and particles movement in order to obtain a close packed monolayer film. The formation mechanism of fabrication defects involving particle agglomeration and uncontrollable voids were analyzed qualitatively based on crystal growth theory, and validation experiments were performed. The formation of highly uniform close-packed monolayer films was demonstrated and the condi- tion requirements for achieving monolayer nanoparticles array with good quality presented.