刀具涂层技术的现状与展望

综述了国内外切削刀具涂层技术的现状 ,展望了涂层技术的发展前景 ,分析了CVD和PVD工艺各自具备的优点和不足。指出 ,开发新的涂层材料和CVD、PVD两种工艺相互补充 。

汽车面漆缩孔成因的理论浅析及排除方法

以表面化学的观点浅析表面张力梯度的出现是产生汽车面漆缩孔缺陷的根本原因，讨论了汽车在线技术服务实践中排除缩孔的方法。提出了解决漆膜缩孔缺陷需要供需双方密切配合、共同努力及加强施工人员培训的重要性。

High-Thermal Conductive Coating Used on Metal Heat Exchanger

Based on modified silicon polyester resin in addition to several functional fillers such as corrosion-resistant fillers, heat-resistant fillers and thermal conductive fillers, a high thermal conductive coating can be made. On the basis of boronnitride(BN) and aluminum nitride(AIN) used as thermal conductive fillers and by means of the testing system of hot disk and heat transfer experiment, researches on the varieties of thermal conductive fillers and the effects of the contents of high-thermal conductive coating have been done, which shows that the thermal conductivity of coating increases with the increase of the quality fraction and the coefficient of thermal conductivity of the thermal conductive fillers of coating. With guaranteeing better heat resistance, stronger corrosion resistance and adhesive force, the coefficient of coating can reach a level as high as 3 W·m-1·K-1.

Microstructure and electrical conductivity of electroless copper plating layer on magnesium alloy micro-arc oxidation coating

In order to impart electrical conductivity to the magnesium alloy micro-arc oxidation(MAO)coating,the electroless copper plating was performed.Effects of plating temperature and complexing agent concentration on the properties of the electroless copper plating layers were studied by measuring their microstructure,corrosion resistance and electrical conductivity.It was found that the optimized plating temperature was 60°C,and the most suitable value of the complexing agent concentration was 30 g/L.Under this condition,a complete and dense plating layer could be obtained.The formation mechanism of the plating layer on magnesium alloy MAO coating was analyzed.A three-stage model of the plating process was proposed.The square resistance of the plated specimen was finally reduced to 0.03Ω/□after the third stage.Through electroless copper plating,the MAO coated sample obtained excellent electrical conductivity without significantly reducing its corrosion resistance.

Influence of Poly（methyl metacrylate） Addition on Resistive Switching Performance of P3HT/P（VDF-TrFE） Blend Films

Organic semiconducting/ferroelectric blend films attracted much attention due to their electrical bistability and rectification properties and thereof the potential in resistive memory devices. Blend films were usually deposited from solution, during which phase separation oc- curred, resulting in discrete semiconducting phase whose electrical property was modulated by surrounding ferroelectric phase. However, phase separation resulted in rough surface and thus large leakage current. To further improve electrical properties of such blend films, poly（methyl metacrylate） （PMMA） was introduced as additive into P3HT/P（VDF-TrFE） semiconducting/ferroelectric blend films in this work. It indicated that small amount of PMMA addition could effectively enhance the electrical stability to both large electrical stress and electrical fatigue and further improve retention performance. Overmuch PMMA addition tended to result in the loss of resistive switching property. A model on the configuration of three components was also put forward to well understand our experimental observations.

Surface resistivity of carbonaceous fiber/PTFE antistatic coatings

Abstract： PAN （Polyacrylonitrile）-based carbonaceous fibers were prepared at the heat treatment temperature （HTT） range of 650 to 900 ℃. The relationships among HTT, carbon content and volume resistivity of the carbonaceous fibers were investigated. The carbonaceous fibers/PTFE （Polytetrafluoroethylene） antistatic coatings were prepared by the spraying technology and the effects of carbonaceous fibers and pigments on surface resistivity of the coatings were systematically discussed. Micrographs provide insight into the antistatic mechanism of the coating. The results show that carbon content of the carbonaceous fibers increases from 68.8% to 74.8% （mass fraction） and the volume resistivity decreases drastically from 1.94× 10^-3 to 8.27× 10 ^-2.cm. The surface resistivity of the antistatic coating is adjustable between 10^5 and 10^8Ω2 to fit the different antistatic materials. Static is dissipated by a conductive network of short fibers and the tunneling effect between the neighboring fibers and conductive pigments. Conductive pigments make the conductive network more perfect and improve the antistatic ability, but insulating pigments acting as barriers for the formation of conductive channel increases the surface resistivity of the coatings. The influence of pigments on the surface resistivity drops gradually with the decrease of the carbonaceous fibers volume resistivity.

Formation and in vitro induction ability of apatite nanobelt coating on silicon

Apatite coating with nanobelt structure was fabricated on single crystal silicon by a two-step method of electrodeposition at 1.0-2.0 mA/cm2 with DC power and vapor-thermal treatment(VTT) at 150-180℃ for 6 h over alkali medium.Scanning electron microscopy(SEM),X-ray diffractometry(XRD),and electron diffraction spectrometry(EDS) were employed to investigate the compositions and morphologies of specimens before or after vapor-thermal treatment.The results demonstrate that nanobelt crystals of coating,0.5-2 μm in width,100 nm in thickness,and 6-10 μm in length,are Ca-deficient apatite(CDA) with a mole ratio of Ca to P approximately of 1.60,which shows similarity of the nanobelt coating to inorganic phase in composition and to collagen in dimension appearing in human hard tissue.Induced nucleation and growth of bone-like apatite were observed on the nanobelt after soaking in a simulated body fluid(SBF) for 6 h and for 3 d,respectively,identifying that nanobelt has good ability for induction of bone-like apatite in SBF.

Research on Axial Trail of High-Speed Gas Painting Automizor

The non linear dynamic model is set up of one type of high speed painting automizor with gas supporting system. The stability of motion and dynamic response of the gas painting automizor system are studied over a relatively wide range of rotating speed by numerical analytic method, the critical velocity under working condition is found, and rotate stability and critical condition are discussed in theory. Furthermore, the range of the critical parameter of the system when Hopf bifurcation occurs and the law between axis trace and bearing clearance are acquired, too.

Biocompatible liquid metal coated stretchable electrospinning film for strain sensors monitoring system

Liquid metals(LMs)are potential inorganic materials which could be applied in flexible and deformable electronics owing to their fluidity,low viscosity,high metallic conductivity,and low toxicity.However,recently reported sensing devices based on LMs required complex processes with high cost.Herein,a flexible three-dimensional(3 D)conductive network was prepared by coating LM droplets onto an electrospun thermoplastic polyurethane(TPU)fiber film.The LM is suspended between the TPU fibers and self-coalesces into a vertically buckled and laterally mesh-like structure,which provides good biocompatibility,conductivity,and stretchability simultaneously.The LM-TPU composite-filmbased flexible device demonstrates a multitude of desired features,such as a widely workable stretching range(0%-200%),sufficient sensitivity under stretching strain(gauge factor(GF)of 0.2 at 200%strain),and outstanding stability and durability(9000 cycles).In vitro biocompatibility experiments show that the LM-TPU composite film directly attached to the skin has excellent biocompatibility.Such strain sensorbased integrated monitoring systems could monitor human body motions in real time,such as muscle movement and joint motion,revealing application prospects in healthcare and human-machine interfacing.

MOCVD derived double-sided YBa_2Cu_3O_(7-δ) films on Y_2O_3 /YSZ/CeO_2 buffered textured metal substrates

We have successfully employed metal-organic chemical vapor deposition （MOCVD） technique to simultaneously deposit double-sided YBa2Cu3O7-δ （YBCO） films on both sides of YzO3/yttria-stabilized zirconia （YSZ）/CeO2 （YYC） buffered biaxially textured Ni-5 at.% W substrates, which is of great prospect to cut the production cost of YBCO coated conductors. X-ray diffraction analysis revealed that both sides of YBCO film were purely c-axis oriented and highly textured. The co-scan of （005） YBCO and Ф-scan of （103） YBCO yielded full width at half maximum （FWHM） values of 4.9° and 6.6° for one side of double-sided YBCO film, respectively, as well as 4.4° and 6.4° for the other side. The current transportation measurements performed on such double-sided 500 nm-thickness YBCO films showed the self-field critical current density （Jc） at 77 K of 0.6 MA/cm^2 and 1.2 MA/cm^2, respectively. Further research is in the process of exploring new solution to improve the Jc in practice.

Transparent conductive reduced graphene oxide thin films produced by spray coating

Reduced graphene oxide thin films were fabricated on quartz by spray coating method using a stable dispersion of reduced graphene oxide in N,N-Dimethylformamide.The dispersion was produced by chemical reduction of graphene oxide,and the film thickness was controlled with the amount of spray volume.AFM measurements revealed that the thin films have near-atomically flat surface.The chemical and structural parameters of the samples were analyzed by Raman and XPS studies.It was found that the thin films show electrical conductivity with good optical transparency in the visible to near infrared region.The sheet resistance of the films can be significantly reduced by annealing in vacuum and reach 58 k?with a light transmittance of 68.69%at 550 nm.The conductive transparent properties of the reduced graphene oxide thin films would be useful to develop flexible electronics.

Manipulation of gold coated microspheres using electrorotation

The electrorotation of microspheres coated with conductive surface is a novel and important technology for label-free biosensors. Using the electroless plating approach, the polystyrene microspheres with 15 μm and 25 μm in diameters were coated with 50 nm gold layer in thickness. The electrorotation experiments on those gold coated polystyrene microspheres (GCPMs) were carried out. The results showed that they rotated in the opposite direction of the electric field in a low frequency range (100-100 kHz), and the maximum rotation speed was higher than that of uncoated microspheres. Based on the theory of traveling wave electroosmosis(TWEO) and induced charge electroosmosis (ICEO), the electrorotation of GCPMs was quantitively analyzed and confirmed by observing the fluid flow around GCPM. The equations describing the electroration speed of GCPMs were proposed, which are consistent with the experiment results.

The highly conducting carbon electrodes derived from spin-coated polyacrylonitrile films

Carbon films prepared from pyrolyzation of spin-casted polyacrylonitrile （PAN） thin films display high electrical conductivity （〉600 S/cm, at 1000 ℃ carbonization）, low sheet resistance （about 100 Y2/square at the PAN film thickness of 70 nm） and partial transmittance. These pyrolyzed PAN （PPAN） films were patterned as bottom electrodes by photolithography, and utilized as drain and source electrodes to fabricate organic field-effect transistor （OFET） devices with a p-type semiconductor （P3HT） and an n-type semiconductor （DPP-containing quinoidal small molecule） through a spin-coating procedure. The results showed that the devices with the PAN electrodes exhibited almost the same excellent performance without any further modification compared to those devices with traditional Au electrodes. Since these PPAN films had the advantages of low-cost, high performance, easier for large-area fabrication, thermal and chemical stability, it should be a promising electrode material for organic electrodes.