Effect of Different Titanium Surface Treatments on the Adhesion Test Result:Dental Application

The aim of the study was to investigate the effect of different surface treatment of titanium(Ti)on the adhesion test results for dental application.Ti substrates roughened by 400 to 1500-grit SiC polish papers and alumina blasting,alkali treated by 5 molar(M)NaOH and KOH solutions and heat treated at the temperature range of 400-800℃were used in this study.The treated samples were subjected to the adhesion test.According to the results of the adhesion test,the adhesive strength showed the highest value for the blasted titanium among all polished and blasted samples.The Ti samples heated at 650℃showed the highest adhesive strength among all heat-treated samples.Further,the adhesion test results indicated the higher adhesive strength of chemically treated samples treated by NaOH rather than that by KOH.The polished and heated Ti samples showed the highest adhesive strength among all samples.

Surface treatment effect on the photocatalytic hydrogen generation of CdS/ZnS core-shell microstructures

CdS/ZnS core-shell microparticles were prepared by a simple two-step method combining ultrasonic spray pyrolysis and chemical bath deposition.The core-shell structures showed enhanced photocatalytic properties compared with those of CdS or ZnS spherical particles.CdS/ZnS photocatalysts with different amount of ZnS loaded as shells were prepared by adjusting the concentrations of Zn and S precursors during synthesis.The optical properties and photocatalytic activity for hydrogen production were investigated and the amount of ZnS loaded as shell was optimized.Thermal annealing and hydrothermal sulfurization treatments were applied to the core-shell structure and both treatments enhanced the material＇s photocatalytic activity and stability by eliminating crystalline defects and surface states.The result showed that thermal annealing treatment improved the bulk crystallinity and hydrothermal sulfurization improved the surface properties.The sample subjected to both treatments showed the highest photocatalytic activity.These results indicate that CdS/ZnS core-shell microspheres are a simple structure that can be used as efficient photocatalysts.The hydrothermal sulfurization treatment may also be a useful surface treatment for metal sulfide photocatalysts.The simple two-step method provides a promising approach to the large-scale synthesis of core-shell microsphere catalysts.

Corrosion behavior and surface treatment of superlight Mg-Li alloys

Mg-Li alloy,as a superlight metallic engineering material,shows great potential in the fields of aerospace and militarydue to its high specific strength,better formability,and excellent electromagnetic shielding performance.The research process ofMg-Li alloys is reviewed and three main problems are pointed out.Aimed at the poor corrosion resistance of Mg-Li alloys,thecorrosion behavior is mainly summarized.The surface treatment technologies,including electroplating,electroless plating,plasmaspraying,molten salt replacement,conversion coating,anodizing,micro-arc oxidation,organic coating,and organic-inorganic hybridcoating,are introduced in detail.Finally,the future development of corrosion and protection of Mg?Li alloys is discussed.

Effect of rare earths surface treatment on tribological properties of carbon fibers reinforced PTFE composite under oil-lubricated condition

The effect of rare earths （RE） surface treatment of carbon fibers （CF） on tribological properties of CF reinforced polytetrafluoroethylene （PTFE） composites under oil-lubricated condition was investigated. Experimental results revealed that RE treated CF reinforced PTFE （CF/PTFE） composite had the lowest friction coefficient and wear under various applied loads and sliding speeds compared with untreated and air-oxidated composites. X-ray photoelectron spectroscopy （XPS） study of carbon fiber surface showed that, after RE treatment, oxygen concentration increased obviously, and the amount of oxygen-containing groups on CF surfaces were largely increased. The increase in the amount of oxygen-containing groups enhanced interfacial adhesion between CF and PTFE matrix. With strong interfacial adhesion of the composite, stress could be effectively transmitted to carbon fibers; carbon fibers were strongly bonded with VITE matrix, and large scale rubbing-off of PTFE be prevented, therefore, tribological properties of the composite was improved.

Effect of surface treatment for aluminum foils on discharge properties of lithium-ion battery

Aluminum foils having thicknesses of 10-20 μm are commonly employed as current collectors for cathode electrodes in Li-ion batteries. The effects of the surface morphology of the foil on battery performance were investigated by using a foil with roughened surface by chemical etching and a plain foil with smooth surface on both sides. For high-conductivity LiCoO2 active materials with large particle size, there are no significant differences in battery performance between the two types of foils. But for low-conductivity LiFePO4 active materials with small particle size, high-rate discharge properties are significantly different. The possibility shows that optimizing both the surface morphology of the aluminum foil and particle size of active material leads to improvement of the battery performance.

Surface Treatment of Polyethylene Terephthalate Film Using Atmospheric Pressure Glow Discharge in Air

Non-thermal plasmas under atmospheric pressure are of great interest in polymer surface processing because of their convenience, effectiveness and low cost. In this paper, the treatment of Polyethylene terephthalate (PET) film surface for improving hydrophilicity using the non-thermal plasma generated by atmospheric pressure glow discharge (APGD) in air is conducted. The discharge characteristics of APGD are shown by measurement of their electrical discharge parameters and observation of light-emission phenomena, and the surface properties of PET before and after the APGD treatment are studied using contact angle measurement, x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It is found that the APGD is homogeneous and stable in the whole gas gap, which differs from the commonly filamentary dielectric barrier discharge (DBD). A short time (several seconds) APGD treatment can modify the surface characteristics of PET film markedly and uniformly. After 10 s APGD treatment, the

Effect of surface treatment on the structure and high-rate dischargeability properties of AB_5-type hydrogen storage alloy

Surface-treated MmNi3.55Co0.75Mn0.4Al0.3 alloy as negative electrode material of nickel-metal hydride battery was employed to improve the high-rate dischargeability. Surface treatment was realized by dipping and stirring the alloy into a HCl aqueous solution with various concentrations at room temperature. The microstructure of the alloy before and after surface treatment was analyzed by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The electrochemical properties before and after surface treatment were compared, and the alloy treated in 0.025 mol/L HCl solution showed the optimal high-rate dischargeability.

Plasma surface treatment of Cu by nanosecond-pulse diffuse discharges in atmospheric air

Nanosecond-pulse diffuse discharges could provide high-density plasma and high-energy electrons at atmospheric pressure. In this paper, the surface treatment of Cu by nanosecond-pulse diffuse discharges is conducted in atmospheric air. Factors influencing the water contact angle （WCA）, chemical composition and microhardness, such as the gap spacing and treatment time, are investigated. The results show that after the plasma surface treatment, the WCA considerably decreases from 87~ to 42.3~, and the surface energy increases from 20.46 mJ m-2 to 66.28 mJ m-2. Results of energy dispersive x-ray analysis show that the concentration of carbon decreases, but the concentrations of oxygen and nitrogen increase significantly. Moreover, the microhardness increases by approximately 30% after the plasma treatment. The aforementioned changes on the Cu surface indicate the plasma surface treatment enhances the hydrophilicity and microhardness, and it cleans the carbon and achieves oxidization on the Cu surface. Furthermore, by increasing the gap spacing and treatment time, better treatment effects can be obtained. The micmhardness in the case of a 2.5 cm gap is higher than that in the case of a 3 cm gap. More oxygen and nitrogen species appear on the Cu surface for the 2.5 cm gap treatment than for the 3 cm gap treatment. The WCA significantly decreases with the treatment thne when it is no longer than 90 s, and then it reaches saturation. In addition, more oxygen-containing and nitrogen-containing groups appear after extended plasma treatment time. They contribute to the improvement of the hydrophilicity and oxidation on the Cu surface.

Effect of surface treatment to inserted ring on Al–Fe bonding layer of aluminium piston with reinforced cast iron ring

In order to improve the bonding strength between piston alloys and cast iron ring of aluminum piston with reinforced cast iron ring,the different methods of the surface treatments(shot blasting and sand blasting) to the cast iron ring are experimented.The optical micrograph shows that an intermetallic layer and a ligulate shaped structure are formed between piston alloys and cast iron base ring.After sand blasting treatment,the ring surface is non-metal shiny,matte-like and has no obvious pits.The intermetallic layer thickness formed between piston alloys and cast iron is thinner and more equally distributed after sand blasting to the ring.The content of the graphite distributed the interfacial zone after the shot blasting treatment is little.With the increase of time by sand blasting,the hardness starts to slightly descend.The bonding strength of the sample by sand blasting is obviously higher than that by shot blasting and increases from 9.32 MPa to 19.53 MPa.

Influence of Different Surface Treatments of H13 Hot Work Die Steel on Its Thermal Fatigue Behaviors

Thermal fatigue checking is the general failure of hot work die steels, which is relative with the structures and properties of the steels and the stress alternated during the employment. The Uddeholm test method on thermal fatigue is used to compare the behaviors of different samples, which are treated with plasma nitriding、plasma sulfur carbon nitriding、boronizing or not treated. The results show that the nitriding improves the thermal fatigue property of the tool steel, while the plasma sulfur carbon nitriding and the boronizing impair the property. The mechanisms are induced as follows. By increasing the hardness and changing the stress distribution in the surface layer, surface treatment can decrease the plastic deformation and the tensile stress during the cycling. Therefore, the generation and growth of the cracks are restrained. On the other hand, as results of surface treating, in the surface layer the toughness declines and the expanding coefficient ascendes; the latter change caused the strengthening of the tensile and compressive stress during the cycling. Thus the resistance to thermal fatigue is weakened. Whether or not the surface treatment is favor to thermal fatigue of tool steels relies on which factor is dominant.

Microstructural characterization of Inconel 718 alloy after pulsed laser surface treatment at different powers

An annealed Inconel 718 alloy was surface-treated by pulsed laser at three different powers（100, 50 and 25 W）. Microstructural changes induced by the laser treatments were characterized by use of electron backscatter diffraction and electron channeling contrast imaging techniques. Results show that both annealing twins and strengthening precipitates profusely existing in the as-received specimen are dissolved at elevated temperatures during the laser irradiation. Meanwhile, in the melting zone（MZ）, densities of low angle boundaries（LABs） are greatly increased with a large number of Laves phases preferentially distributed along such LABs. For different specimens, widths and depths of their MZs are found to be gradually reduced with decreasing the laser powers. Orientation analyses reveal that the columnar grains in the MZ of the 100 W specimen could inherit orientations existing in the matrix while lower laser powers promote the formation of more nuclei with scattered orientations to grow to be granular grains in the MZ. Hardness tests reveal that the MZs of all laser-treated specimens are softer than the matrix probably due to both precipitate dissolution and grain coarsening.

Surface Nanocrystallization of C45E4 Steel by Ultrafast Electropulsing-ultrasonic Surface Treatment

The effect of high-energy electropulsing-ultrasonic surface treatment（EUST） on the surface properties and the microstructure evolution of C45 E4 steel was investigated. Refined microstructure and reduced surface roughness were obtained owing to the surface nanocrystallization process. Compared with the ultrasonic surface treatment（UST）, the impact depth of the surface strengthened layer was increased by 40% to 700 μm after EUST. The average grain size of the surface nanocrystallization layer was reduced to 30-50 nm. The surface roughness of the C45 E4 steel was reduced to 0.25 μm, and the surface microhardness was dramatically enhanced to 460 HV. The improvement of microstructure and micro-hardness at ambient temperature was likely attributed to the acceleration of atomic diffusion and the enhancement of plastic deformation ability in the surface strengthened layer under the influence of electropulsing. Due to the electropulsing-assisted ultrasonic strengthening effect, the surface nanocrystallization in this ultrafast procedure was noticeably enhanced.

Study on Surface Treatments on CdSe Wafers

The surface treatments on CdSe wafers were studied by means of SEM,XPS and micro-current test instrument.The relations between electrical properties of CdSe wafers and surface topography,composition and structure were analyzed.The results show that the change of surface composition by etching is beneficial to decrease leakage current.Meanwhile,the increase of oxygen on surface caused by passivation can largely decrease leakage current.When passivating time is 40 min,the wafers surface appears smooth and compact,which will decrease the density of surface state,the optimal electrical property of the wafer is therefore obtained.

Surface treatment of titanium dioxide nanopowder using rotary electrode dielectric barrier discharge reactor

Titanium dioxide(Ti O_(2))nanopowder(P-25;Degussa AG)was treated using dielectric barrier discharge(DBD)in a rotary electrode DBD(RE-DBD)reactor.Its electrical and optical characteristics were investigated during RE-DBD generation.The treated TiO_(2)nanopowder properties and structures were analyzed using x-ray diffraction(XRD)and Fourier-transform infrared spectroscopy(FTIR).After RE-DBD treatment,XRD measurements indicated that the anatase peak theta positions shifted from 25.3°to 25.1°,which can be attributed to the substitution of new functional groups in the TiO_(2)lattice.The FTIR results show that hydroxyl groups(OH)at 3400 cm-1 increased considerably.The mechanism used to modify the TiO_(2)nanopowder surface by air DBD treatment was confirmed from optical emission spectrum measurements.Reactive species,such as OH radical,ozone and atomic oxygen can play key roles in hydroxyl formation on the TiO_(2)nanopowder surface.

Influence of Surface Treatment on the Corrosion Resistance of Stainless Steel in Simulated Human Body Environment

In the present research, the influence of chromium enrichment by surface treatment on corrosion resistance of type 316L stainless steel in body environment was investigated. For this study, weight loss test during 18 months, cyclic and liner polarization tests before and after surface treatment and metallography by electron and light microscopy were used to evaluate the effectiveness of the proposed method. In addition, X-ray photoelectron spectroscopy （XPS） method was used to determine the chromium concentration in the surface layer after surface treatment. Results show that the surface treatment has improved corrosion resistance of the type 316L stainless steel in body environment.

Effect of Mechanical Surface Treatment on the Bonding Mechanism and Properties of Cold‑Rolled Cu/Al Clad Plate

In the case of valuable cold-rolled Cu/Al clad plates,billet surface treatment before rolling is a significant process that can affect the bonding efficiency and quality.While the current studies primarily focus on the influence of rolling parameters,insufficient attention has been paid to surface treatment.In this study,the effects of mechanical surface treatment on the bonding mechanism and bonding properties of cold-rolled Cu/Al clad plates were investigated.The results showed that different mechanical surface treatments have significant effects on the surface morphology,roughness,and residual stress.In addition,the effect of surface mechanical treatment on bonding quality was also observed to be critical.When the grinding direction was consistent with the rolling direction(RD),the bonding quality of the Cu/Al clad plates was significantly improved.After surface treatment along the RD for 20 s,the Cu/Al clad plates showed the highest shear strength(78 MPa),approximately four times as high as that of the unpolished samples.Simultaneously,the peel strength of this process was also significantly higher than that achieved via the other processes.Finally,on the basis of the surface morphology,roughness,and residual stress,the effect of surface treatment on the bonding mechanism and bonding properties of Cu/Al clad plates was analyzed.This study proposes a deeper understanding of the bonding behavior and bonding mechanism for cold rolled clad plates processed via mechanical surface treatment.

Surface Treatment of Polypropylene Films Using Dielectric Barrier Discharge with Magnetic Field

Atmospheric pressure non-thermal plasma is of interest for industrial applications. In this study, polypropylene （PP） films are modified by a dielectric barrier discharge （DBD） with a non-uniform magnetic field in air at atmospheric pressure. The surface properties of the PP films before and after a DBD treatment are studied by using contact angle measurement, atomic force microscopy （AFM） and X-ray photoelectron spectroscopy （XPS）. The effect of treatment time on the surface modification with and without a magnetic field is investigated. It is found that the hydrophilic improvement depends on the treatment time and magnetic field. It is also found that surface roughness and oxygen-containing groups are introduced onto the PP film surface after the DBD treatment. Surface roughness and oxygen-containing polar functional groups of the PP films increase with the magnetic induction density. The functional groups are identified as C-O, C=O and O-C=O by using XPS analysis. It is concluded that the hydrophilic improvement of PP films treated with a magnetic field is due to a greater surface roughness and more oxygen-containing groups.

The Effect of Plasma Surface Treatment on a Porous Green Ceramic Film with Polymeric Binder Materials

To reduce time and energy during thermal binder removal in the ceramic process, plasma surface treatment was applied before the lamination process.The adhesion strength in the lamination films was enhanced by oxidative plasma treatment of the porous green ceramic film with polymeric binding materials.The oxygen plasma characteristics were investigated through experimental parameters and weight loss analysis.The experimental results revealed the need for parameter analysis,including gas material,process time,flow rate,and discharge power,and supported a mechanism consisting of competing ablation and deposition processes.The weight loss analysis was conducted for cyclic plasma treatment rather than continuous plasma treatment for the purpose of improving the film’s permeability by suppressing deposition of the ablated species.The cyclic plasma treatment improved the permeability compared to the continuous plasma treatment.

Surface Treatment of Polypropylene Powders Using a Plasma Reactor with a Stirrer

A radio frequency argon plasma reactor with a stirrer was employed for the surface treatment of polypropylene （PP） powders. The changes in the superficial contact angle and the superficial composition of the un-treated and treated PP powders were analyzed by means of water contact angle （WCA） measurement, X-ray photoelectron spectroscopy （XPS） and attenuated total reflection Fourier transform infrared spectroscopy （ATR-FTIR）. The water contact angle changed from the original value of 130.2° before plasma treatment to the value of 73.6° after treatment for 5 minutes. With the increase in plasma treating time, there were a decrease in the water contact angle and an increase in the content of oxygen containing polar functional groups （i.e., C-O, C=O and O-C=O）. Both XPS and ATR-FTIR results indicated that the plasma treatment led to the formation of oxygen containing polar functional groups due to oxidation on the surface of the PP powders, and the trend of variation of the water contact angle with plasma treating time was related to the concentration of oxygen atom on the treated PP powders surface. Furthermore, the aging of the plasma-treated PP powders was investigated.

Influence of surface treatment of carbon fiberson electrochemical crystallization of calcium phosphate

Electrodeposition technique was used to coat calcium phosphate on carbon fiber which can be used to reinforce hydroxyapatite. The differences between fibers treated with and without nitric acid in electrodeposition were evaluated. The X-ray diffractometry results show that CaHPO4·2H2O is obtained as the kind of calcium phosphate coating on carbon fiber. The scanning electron microscopy photographs and deposit kinetic curve indicate that the influences of the functional group attained by nitric acid treatment, the crystal morphology and crystallization of the coating layers on the fiber with and without treatment rate are obviously different. The functional group, especially the acidic group, can act as nucleation centers of electrochemical crystallization.