Fabrication and its characteristics of hard coating Ti-Al-N system prepared by DC magnetron sputtering

Pseudobinary Ti 1 x Al x N films were synthesized on Si (100) wafer by DC magnetron sputtering method using Ti 1 x Al x alloy targets with different Al contents. The composition of the Ti 1 x Al x N films was determined by electron probe microanalysis (EPMA). Structural characteristic was performed by X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM). First principles virtual crystal calculations for the Ti 1 x Al x N disordered alloys were used for the XRD simulations. The crystalline structure of the Ti 0.61 Al 0.39 N film was found to be a metastable single phase with NaCl (B1) structure. Its lattice constant, determined by XRD, was less than that of pure TiN. With the increase of Al content, the lattice constant of B1 phase was continually decreased, while würtzite (B4) structure was observed in the Ti 0.40 Al 0.60 N film. When x reached 0.75, the B1 phase disappeared, and only B4 phase was remained. The critical Al content for the phase transition from NaCl to würtzite structure in this paper was about 0.60, which could be explained by both the thermodynamic model and the electron theory. As-deposited Ti 1 x Al x N films exhibited excellent mechanical properties. Hardness measurements of Ti 1 x Al x N films showed a high value of 45GPa for x=0.39 and was decreased to value of 27 GPa with increasing Al at x=0.60.

Investigation of High Catalyteal Durability for Porous Pt Films Deposited via Magnetron Sputtering

Porous Pt thin films were prepared on carbon papers by a single-step ultra-high dc magnetron sputtering method to obtain ideal electrodes for proton exchange membrane fuel cells.The platinum loading of the electrocatalyst layer is controlled at about 0.1 mg·cm^(-2).Structural characteristics and catalytic activities of the films were analyzed by scanning electron microscopy,atomic force microscopy,X-ray diffraction,cyclic voltammetry,and stress durability testing methods.The effect of treatment conditions of a substrate on the structural and performance characteristics of the catalytic films was shown as well.Films produced on acid-treated carbon papers at the argon pressure of 0.01 mbar possessed a homogeneous,highly developed surface along with a porous structure.Compared to Pt/TCPW(Toray carbon papers soaked in ultrapure water)electrodes,the film obtained on the acid-treated substrate had a larger electrochemical surface area(163.33 m^(2)·g^(-1))and exhibited better catalytic stability and durability due to a porous structure as a result of Pt particle accumulation.

Insights into the oxidation resistance mechanism and tribological behaviors of multilayered TiSiN/CrVxN hard coatings

In the last decades,vanadium alloyed coatings have been introduced as potential candidates for self-lubrication due to their perfect tribological properties.In this work,the influence of V incorporation on the wear performance and oxidation resistance of TiSiN/CrN film coatings deposited by direct current(DC)reactive magnetron sputtering is investigated.The results show that vanadium incorporation significantly decreases the oxidation resistance of the coatings.In general,two layers are formed during the oxidation process:i)Ti(V)O_(2) on top,followed by a protective layer,which is subdivided into two layers,Cr_(2)O_(3) and Si-O.ii)The diffusion of V controls the oxidation of V-containing coatings.The addition of vanadium improves the wear resistance of coatings,and the wear rate decreases with increasing V content in the coatings;however,the friction coefficient is independent of the chemical composition of the coatings.The wear of the V-containing coatings is driven by polishing wear.

Preparation and characterization of single(200)-oriented TiN thin films deposited by DC magnetron reactive sputtering

Single(200)-oriented TiN thin films were deposited on quartz substrate by direct current(DC) magnetron reactive sputtering process at a wide range of substrate temperature from 200 to 600 ℃.The effects of sputtering pressure and substrate temperature on the crystalline nature,morphology,electrical and optical properties of the deposited thin films were analyzed by X-ray diffraction(XRD),atomic force microscopy(AFM),four-point resistivity test system and ultraviolet visible near-infrared(UV-Vis-NIR) spectroscopy,respectively.The results show that single(200)-oriented TiN thin films can be obtained at a wide range of substrate temperature from 200 to 600 ℃ with the grain size increasing from 35.9 to 64.5 nm.The resistivity of the product is as low as95 μΩ·cm,and the value of the optical reflectance is above68 % in the near-infrared(NIR) range of 760-1500 nm.

Preparation and properties of tungsten-doped indium oxide thin films

Tungsten-doped indium oxide (IWO) thin films were deposited on glass substrate by DC reactive magnetron sputtering. The effects of sputtering power and growth temperature on the structure, surface morphology, optical and electrical properties of IWO thin films were investigated. The thickness and surface morphology of the films are both closely dependent on the sputtering power and the substrate temperature. The transparency of the films decreases with the increase of the sputtering power but is not seriously influenced by substrate temperature. All the IWO thin film samples have high transmittance in near-infrared spectral range. With either the sputtering power or the growth temperature increases, the resistivity of the film decreases at the beginning and increases after the optimum parameters. The as-deposited IWO films with minimum resistivity of 6.4 10 4 cm were obtained at a growth temperature of225 C and sputteringpower of 40 W, with carrier mobility of 33.0 cm 2 V 1 s 1 and carrier concentration of 2.8 10 20 cm 3 and the average transmittance of about 81% in near-infrared region and about 87% in visible region.

Hard X-ray focusing resolution and efficiency test with a thickness correction multilayer Laue lens

The multilayer Laue lens(MLL) is a diffractive focusing optical element which can focus hard X-rays down to the nanometer scale. In this study, a WSi_(2)/Si multilayer structure consisting of 1736 layers, with a 7.2-nm-thick outermost layer and a total thickness of 17 μm, is prepared by DC magnetron sputtering. Regarding the thin film growth rate calibration, we correct the long-term growth rate drift from 2 to 0.6%, as measured by the grazing incidence X-ray reflectivity(GIXRR). A one-dimensional line focusing resolution of 64 nm was achieved,while the diffraction efficiency was 38% of the-1 order of the MLL Shanghai Synchrotron Radiation Facility(SSRF) with the BL15U beamline.

Enhancing durability of 3D printed polymer structures by metallization

Additive manufacturing or three dimensional(3D)printing is a promising technique for producing complex geometries and high precision structures from various types of materials.The technique was particularly developed for polymer materials such as acrylonitrile–butadiene–styrene(ABS)and found its way to different industries such as aerospace,automotive,electronics,medicine and construction.However,during service in outdoor environments,3D printed polymer structures are exposed to different environmental conditions such as UV radiation and moisture,causing a significant degradation in the microstructure and mechanical properties of the structures.This study offers a novel method to improve durability of 3D printed polymer structures against accelerated environmental conditions by deposition of a metallic thin film(i.e.copper)on the structural surface.ABS specimens are 3D printed using fused deposition modeling(FDM)technique and metalized via DC magnetron sputtering.The characterization of durability of 3D printed ABS specimens in outdoor environments is carried out by monitoring flexural properties and microstructure of samples over the course of exposure in a controlled environmental chamber.

Deposition and characterization for high-quality Ti-Ni-Cu thin films with higher Cu content

In order to attain high-quality Ti-Ni-Cu film,the surface morphologies,chemical compositions and mechanical properties of Ti-Ni-Cu thin films prepared by direct current(DC)magnetron sputtering at various processes were characterized by scanning electron microscopy(SEM),X-ray diffractometer(XRD)and tensile tests.The type of substrates,Ar pressure and sputtering power had significant effects on the quality and chemical composition of Ti-Ni-Cu thin film.Compared with Si and SiO_(2) slides,it was easier to obtain freestanding films by adopting glass or piezoid slide as substrates.The Ti-Ni-Cu thin film deposited at lower pressure(0.10 Pa)had a better density.The surface was featured with porous structure in the Ti-Ni-Cu thin film prepared by higher Ar pressure of 0.36 Pa.In addition,both the tensile strength and strain of annealed Ti-Ni-Cu thin film continuously increased with Ar pressure decreasing.Higher density contributed to the superior mechanical properties.The deposition rate firstly increased and then decreased with Ar pressure and sputtering power increasing.The composition of deposited Ti-Ni-Cu film can be tailored by changing sputter power.The deposited Ti-Ni-Cu thin films at different processing parameters were in amorphous state.In short,the present study offered the important theoretical basis for the preparation of Ti-Ni-Cu thin film with higher quality and performance.

Tribological properties of platinum/ruthenium/nitrogen doped diamond-like carbon thin films deposited with different negative substrate biases

The platinum/ruthenium/nitrogen doped diamond‐like carbon(PtRuN‐DLC)thin films were deposited on Si substrates via DC magnetron sputtering by varying negative substrate bias.The tribological performance of the PtRuN‐DLC films was systematically investigated using ball‐on‐disc microtribological test.The Raman results showed that the increased negative substrate bias significantly increased the number of sp3 bonds in the PtRuN‐DLC films as a result of the increased kinetic energies of impinging ions.The adhesion strength of the PtRuN‐DLC films apparently decreased with increased negative substrate bias due to the promoted residual stress in the films.The tribological results clearly revealed that the increased negative substrate bias decreased the friction and wear of the PtRuN‐DLC films by improving the sp3 bonded cross‐linking structures of the films.It can be concluded that the PtRuN‐DLC films could effectively prevent their underlying Si substrates from wear as the negative substrate bias had a significant influence on the tribological properties of the PtRuN‐DLC films.