Anti-abrasion Properties Research Articles

Controlled fabrication of NiO/ZnO superhydrophobic surface on zinc substrate with corrosion and abrasion resistance

The paper reports on the preparation of NiO/ZnO superhydrophobic surfaces (SHS) on zinc via chemical substitution/deposition and thermal annealing. The resulting surfaces display superhydrophobic behavior with a water contact angle (WCA) of 153° and a sliding angle (SA) of ∼5° without the use of any additional organic coating. Using the Cassie-Baxter equation, it is found that about 91.6% serves as the contact area of the water droplet and air, leading to the roll down property of the water droplet on the surface. The surface superhydrophobicity is controlled and influenced by various preparation conditions: the thermal treatment, which causes the generation of NiO and ZnO layers, and the formation of polygonal honeycomb structures and disappearance of silk flower-like clusters. The resulting NiO/ZnO SHS exhibit roll down, anti-corrosion and anti-abrasion properties. The corrosion current density of the NiO/ZnO SHS (5.7 × 10−4 A cm−2) is decreased by more than 1 order of magnitude when compared to the untreated Zn surface (1.4 × 10−3 A cm−2). EIS results also indicate that the SHS possesses higher anti-corrosion performance. The superhydrophobic sample, after annealing treatment, can sustain a collapsing force of about 7.8 N, which is better than the superhydrophilic sample without annealing treatment (∼5.2 N). This controlled fabrication process may offer new avenues for designing superhydrophobic surfaces with corrosion resistance for more practical applications.

An EIS analysis on corrosion resistance of anti-abrasion coating

A coating for anti-corrosion and anti-abrasion application was fabricated successfully. And the ratio among fillers, which would affect the function of coating, was studied in this paper by orthogonal experiments. Physical property, corrosion resistant performance and anti-abrasion property were comprehensively evaluated. Due to the alternating structure with soft and hard, the addition of antiseptic fillers has no effect on anti-abrasion property. However, the corrosion resistant performance revealed remarkable improvement in comprehensive salt fogging test. EIS was also conducted to analyze the corrosion process, the impedance values showed first decreasing then increasing on behalf of corrosion resistance. The results showed the coating revealed best performance when the ratio of hard fillers and antiseptic fillers is 1:1. What's more, the small particle showed better shielding action in the corrosion process.

Friction and morphology of pleural mesothelia

To verify the hypothesis that by enmeshing lubricants, microvilli reduce the coefficient of kinetic friction (μ) of pleural mesothelium, μ was measured during reciprocating sliding of rabbit’s visceral against parietal pleura before and after addition of hyaluronan, and related to the morphological features of the microvillar network. Because no relation was found between μ or μ changes after hyaluronan and microvillar characteristics, the latter are not determinants of the frictional forces which oppose sliding of normal mesothelial surfaces under physiological conditions, nor of the effects of hyaluronan. Addition of hyaluronan increased μ slightly but significantly in normal specimens, probably by altering the physiological mix of lubricants, but decreased μ of damaged mesothelia, suggesting protective, anti-abrasion properties. Indeed, while sliding of an injured against a normal pleura heavily damaged the latter and increased μ when Ringer was interposed between the surfaces, both effects were limited or prevented when hyaluronan was interposed between the injured and normal pleura before onset of sliding.

Liquid phase deposition of titanium oxide film on stainless steel substrate

In this study, liquid phase deposition (LPD) was used to prepare titanium oxide (TiO2) films on stainless steel substrates. The raw materials used were ammonium hexafluorotitanate and boric acid. Various concentrations of boric acid and annealing conditions were employed to examine the influences on hydrophilicity, anti-corrosion and anti-abrasion. The optimum conditions were a boric acid concentration of 0.7M and oxygen annealing at 800°C for 1h. The water contact angle was reduced from 82.62° to 2.51°, indicating that the hydrophilic properties of the stainless steel were enhanced after TiO2 film deposition. Regarding corrosion, the corrosive current reduced from −4.75A/cm2 to −6.52A/cm2 by 3.65wt.% of HCl. The Vickers hardness value (HV) of the stainless steel substrate increased from 254 to 820. Therefore, TiO2 thin films prepared using LPD can improve the hydrophilic, anti-corrosion, and anti-abrasion properties of stainless steel substrates.

Experimental Study on a New Combination Processing Technology of Polycrystalline Diamond

Polycrystalline diamond compacts (PCD) has high hardness, good anti abrasion property. The precision processing technology of PCD is key technology in applications. This article introduces a new combination machining method of polycrystalline diamond (PCD). This machining method combines diffusion machining with free abrasive milling. In the processing polycrystalline diamonds in PCD were removed by the diffusing; binders in PCD were removed by grinding. The two main factors in the processing were described. The results of the experiment indicate that grinding speed, abrasives particle - size are factors of the significant impact.

Experimental and Application Study of a New Type High Strength Repairing Mortar for Hydraulic Concrete

Be aimed at concrete surface damages of hydraulic concrete structures, a high strength repairing mortar was made in this paper. The mechanical properties and durability of repairing mortar were studied. Samples of repairing mortar preparation in laboratory and in field were tested respectively and its repair process and quality control was discussed. The results show that the repairing mortar has good mechanical property, obviously anti-abrasion property and excellent bonding performance. It can play an important role in concrete repairing in the field of hydraulic engineering. The sample property from field is a little lower than of laboratory made but still superior to design index. To achieve good repairing effect, construction technology and quality control is also the important factor.

Thermal stability and abrasion resistance of polyacrylate/nano-silica hybrid coatings

Polyacrylate (PAE)/nano-silica (SiO2) hybrids were prepared by an in situ sol–gel process of tetraethyl orthosilicate in the presence of PAE toluene solution. The hybrid coatings were fabricated using a PAE/SiO2 suspension by the traditional casting. Their intermolecular interaction and morphology, as well as thermal, mechanical, and optical properties, were investigated using Fourier transform infrared spectroscopy, field-emission scanning electron microscope, differential scanning calorimetry and TG/DTA thermogravimetric analysis, coating impact testing, and UV–Vis spectroscopy, respectively. At the same time, their abrasive properties were carried out by abrasion resistance and nanoindentation tests. The results indicate that silica nanoparticles, with diameter about 30 nm, can disperse homogeneously in the PAE matrix, where hydrogen bonds between the PAE and nano-silica are formed. Therefore, homogeneous dispersion of nano-silica particles provides high transparency for the PAE/SiO2 hybrid coating as the size of nano-silica phase is much smaller than the wavelength (390–770 nm) of visible light. PAE/nano-silica hybrid coatings have increased T g and thermal stability including the onset decomposition temperature, 10 % weight loss temperature, and char at 700 °C. Additionally, the incorporation of nano-silica particles improves the glossiness of the PAE/nano-silica hybrid coatings and enhances their abrasion resistance and surface hardness. The nano-silica content has obvious effect on the thermal, mechanical, optical, and anti-abrasion properties of PAE/SiO2 hybrid coatings. With the consideration of all the properties of hybrid coatings, the PAE/SiO2 hybrid containing 10 phr of nano-silica has the optimal composition. These PAE/nano-silica hybrid coatings have potential applications in high-performance hologram image recording.

In-mold Decoration(IMD) 포일용 경질 코팅 수지 설계 및 전자빔 조사가 IMD 포일 구성층에 미치는 영향

실란 커플링제를 사용하여 알루미나 나노 입자의 표면을 처리하였다. 표면을 개질한 나노 입자를 in-mold decoration(IMD) 포일의 경질 코팅 층에 도입하여 표면 경도 및 내마모성을 중심으로 도막의 물성 변화를 평가하였다. 전자빔(electron beam, EB) 조사가 IMD 포일을 구성하는 color layer 및 anchor layer에 미치는 영향을 색도변화와 cross-cut tape 시험을 통하여 평가하였다. 또한 EB 조사 온도에 따른 경화 거동을 표면 물성 변화 평가 및 Fourier transform infrared(FTIR) spectroscopy 관찰을 통해 정량적으로 분석함으로써 EB 경화 공정의 실용화에 필요한 데이터베이스를 구축하였다. The silane coupling agent, 3-(trimethoxysilyl)propyl methacrylate (<TEX>${\gamma}$</TEX>-MPTS), was grafted on the surface of alumina nanoparticles. We used the surface modified nanoparticles in the hard coating layer for in-mold decoration (IMD) foils and evaluated the coating properties such as hardness and anti-abrasion property. The effects of electron beam (EB) irradiation on color layer and anchor layer of IMD foils were observed through the difference in color and the cross-cut tape test, respectively. Also, cure kinetics as studied quantitatively under various reaction temperatures by analysis of surface properties and Fourier transform infrared (FTIR) spectroscopy. From these results, we constructed database for the commercial exploitation of EB curing system.

Carbon Black Filled Powdered Natural Rubber

Carbon black (CB) filled powdered natural rubber [P(NR/N234)] was prepared using a patented method of latex/CB coagulation technology. The influence of curing recipes and CB contents on the curing, mechanical, and dynamic properties were studied in depth, and the results were compared with that of NR/N234 compounds based on traditional dry mixing of bale NR and CB. The results showed that, compared with NR/N234, P(NR/N234) showed higher tensile strength, tear strength, rebound elasticity and flexibilities, and the antiabrasion properties were similar, while the dynamic temperature-build-up and dynamic compression permanent set were about 50% of that of NR/N234. The analysis based on scanning electron micrographs (SEM) and the Payne effect showed that the fine dispersion of CB in the rubber and the enhanced interaction between CB and rubber contributed to the excellent properties of P(NR/N234), sufficient that they make P(NR/N234) a potential material for the tread compounds of heavy-duty all-steel cord radial tires.

Pareto Optimization of Electro Discharge Machining of Titanium Nitride-Aluminium Oxide Composite Material Using Genetic Algorithm

Titanium nitride-aluminium oxide (TiN-Al2O3) is a new generation ceramic composite material having potential for many industrial applications as it possess high resistance to thermal degradation, anti-wear and anti-abrasion properties. In the present research the characteristic features of EDM process are explored through Taguchi methodology based experimental studies with various process parametric combinations. Finally the process has been optimized using Genetic algorithm based Pareto optimization search. From Pareto optimal search the technology guideline for optimal parameter settings have been selected. The present research approach is extremely useful for maximizing the productivity while maintaining the geometrical accuracy within desired limit.

In-mold Decoration 포일에 사용되는 경질 코팅 수지의 전자빔 경화

In-mold decoration 포일의 경질 코팅 층에 사용하는 수지를 대상으로 전자빔(electron beam, EB) 경화에 관한 연구를 수행하였다. 시료에 다른 양의 EB를 조사하고, 경화 반응 정도를 Fourier transform infrared(FTIR) spectroscopy를 사용하여 관찰하였다. EB 조사선량 증가에 따른 코팅 물성의 변화를 표면 경도와 내마모성을 중심으로 알아보았다. 또한 나노 입자 첨가가 코팅 물성에 미치는 영향을 조사하였다. 본 연구로부터 얻은 실험적 결과는 자외선 (ultraviolet, UV) 경화 시스템과 유사한 EB 경화 시스템의 상업적 개발에 이용될 수 있을 것으로 기대된다.

Improvement of surface hardness of duplex stainless steel by laser shock hardening for the application to seawater desalination pump

A high-capacity pump for seawater desalination plant is open to highly corrosive and abrasive environment. To improve anti-corrosion and anti-abrasion properties of pump material, laser modification technology can be applied to the surface of pump material. In this work, experimental results for the laser shock hardening of 2205 duplex stainless steel (22% chromium—5% nickel) for the application to rotating pump parts are reported. The changes in surface hardness and morphology before and after laser shock hardening are investigated for varying process conditions. It is demonstrated that the hardness of duplex stainless steel can be significantly enhanced, up to 30%, by properly controlling the process parameters. The applicability of laser shock hardening for surface treatment of mechanical parts of seawater desalination pumps is discussed.

Study on the Bond and Anti-Abrasion Performance of Repair Materials for Hydraulic Concrete

The bond and anti-abrasion performance of repair materials are the key factors for successful repair of hydraulic concrete. Acrylic acid emulsion (AAE) mortar, silica fume (SF) mortar, high strength (HS) mortar, polypropylene (PP) fiber mortar and basalt fiber (BF) mortar were prepared and their direct tensile bond strength, splitting tensile bond strength, abrasion resistance and SEM analysis of bond interface are studied in this paper. The results show that the highest direct tensile bond strength was recorded for fiber mortar. But compared to homogenous specimen’s tensile strength, AAE mortar showed the highest direct tensile bond strength. The anti-abrasion properties of repair mortars were tested with decreasing performance recorded in the following order: PP fiber mortar, SF mortar, BF mortar, HS mortar and AAE mortar. Compared with the HS mortar without fiber, the wear rate of PP fiber mortar was decreased by 29.2 % and the anti-abrasion strength was increased by 37.7%. This shows that adding fiber can greatly improve the anti-abrasion property. SEM analysis showed that addition of PP fiber and BF into repair mortar did not change the type of hydrates. The interface of AAE mortar was level and dense. The bond interface of SF mortar was uniform without big porosity. Addition of super plasticizer, the bond interface of HS mortar presented a large quantity of fibrous the CSH gel and less porosity which could improve the mortar bond effect effectively.

Electro Discharge Machining of Titanium Nitride-Aluminium Oxide Composite for Optimum Process Criterial Yield

Titanium nitride-aluminium oxide (TiN–Al2O3) is a new generation ceramic composite material having potential for many industrial applications as it possesses high resistance to thermal degradation, anti-wear and anti-abrasion properties. But conventional machining of such ceramic composite is difficult to perform for some of its peculiar properties like anisotropy, low thermal conductivity, and abrasive nature of the reinforcing phases. In the present investigation, non-conventional machining like electro discharge machining (EDM) has been carried out to machine the material. Energy dispersive X-ray spectroscopy and X-ray diffraction analysis have also been carried out on the composite matrix to verify the presence of two distinguishable phases of TiN and Al2O3. The present article reports the effects of EDM process parameters on material removal rate, electrode wear rate, radial overcut, and taper angle while machining TiN–Al2O3 composite. The characteristic features of the EDM process are explored through Taguchi L9 orthogonal array design–based experimental studies with various process parametric combinations. Finally, optimum parameter settings for each response factor are obtained and tested through verification experiments. The whole experimental study indicates that EDM has a very good potential in machining of TiN–Al2O3 ceramic composite in some particular ranges of process parameters.

Microstructure and tribological properties of TiN, TiC and Ti(C, N) thin films prepared by closed-field unbalanced magnetron sputtering ion plating

TiN, TiC and Ti(C, N) films have been respectively prepared using closed-field unbalanced magnetron sputtering ion plating technology, with graphite target serving as the C supplier in an Ar–N 2 mixture gas. Bonding states and microstructure of the films are characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) in combination with transmission electron microscopy (TEM). The friction coefficients are measured by pin-on-disc test and the wear traces of deposited films are observed by optical microscope. Results show that the TiN film and Ti(C, N) film exhibit dense columnar structure while the TiC film exhibits a mixed microstructure of main nanocrystallite and little amorphous phases. The Ti(C, N) film has the highest microhardness value and the TiC film has the lowest. Because of small amount of pure carbon with sp 2 bonds existing in the film, the friction coefficients of Ti(C, N) and TiC multilayer films are lower than that of TiN film. In addition, the multilayer structure of films also contributes visually to decrease of friction coefficients. The TiC film has extremely low friction coefficient while the wear ratio is the highest in all of the films. The results also show that the Ti(C, N) film has excellent anti-abrasion property.

Dry abrasion property of TiN-matrix coating deposited by reactive High Velocity Oxygen Fuel (HVOF) spraying

A TiN-matrix coating with a thickness of about 400 μm was prepared by reactive high velocity oxygen fuel (HVOF) spraying on carbon steel in air. The phase composition, microhardness, and antiabrasion properties of the coating were investigated using x-ray diffraction (XRD), an energy dispersive spectrometer (EDS), a scanning electron microscope (SEM), a Vickers microhardness tester, and block-on-ring abrasive equipment. The abrasion mechanism of TiN-matrix coating under dry abrasion conditions was also discussed. The results indicate that the composition of the coating is main phases of TiN and TiN0.3, minor phases of Ti2O3, and TiO2. The TiN-matrix coating possesses high microhardness and relatively good toughness. Furthermore, the friction coefficient of the coating decreases with the increment of applied load. The interstratified distribution of titanium oxides can act as a solid lubricant during the wear test. The main abrasion mechanism of the TiN-matrix coating is adhesion wear. In addition, the coating with self-lubricating property can improve the antiwear property of the substrate significantly.

Sliding tribological behavior of AlCrN coating

The sliding tribological behavior of the PVD AlCrN coating against Si 3N 4 ball have been investigated by using the CETR multi-functional UMT-2 test system under two sliding conditions (bidirectional and unidirectional). Reciprocating sliding tests (bidirectional) were performed under varied normal loads (5, 10 and 20 N) at sliding velocity of 0.48 m/min. Ball-on-disc tests (unidirectional) were performed at varied sliding velocities (0.48 and 5 m/min) under normal load of 5 N. The wear scars of the coating were evaluated by surface profilometer, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the sliding wear mechanism of the coating was consequently discussed. The results showed that AlCrN coating had excellent anti-abrasion properties. Both the normal load in reciprocating sliding test and the sliding velocity in ball-on-disc test had significant influence on the sliding tribological behavior of the AlCrN coating. The combination of abrasion and oxidation was the main sliding wear mechanism for the AlCrN coating. The wear resistant and thermally stable oxides formed by the tribo-chemical reactions of chromium and aluminum protected the AlCrN coating against wear admirably.

Handling hostile environments at a stroke

Premature seal failure in reciprocating pumps present users with both operational and maintenance problems. In general, standard elastomers in the plunger packing fail due to frictional heat and abrasion generated by the mechanical movement of the plunger. In this article Fred Pipper of Utex Industries, describes the development and testing of a new nitrile-based elastomer system for sealing reciprocating pumps, which possesses high wear and anti-abrasion properties.

Ultrasonic velocities in cast aluminium alloy-shell char particle composites

Aluminium-ceramic particle composites are technologically important because of their good antiabrasion and anti-friction properties. These composites have hitherto been produced by relatively expensive powder-metallurgy techniques and their uses have consequently been restricted to specialist applications covering a few manufacturing industries. In recent years, considerable attention has been paid to evolving methodologies within the framework of conventional casting procedures for the processing of these composites on a cost-effective basis so that their appeal extends to wider sections of industries. Some of the aluminium-ceramic particle composites successfully prepared by liquid metallurgy techniques include those containing dispersions of alumina [1] and zircon [2] for anti-abrasion applications and mica [3] and graphite [4] for anti-friction applications. Another recent development concerns the successful dispersion of porous carbon in the form of coconut-shell char particles in aluminium alloy matrix and the cast composites have shown good anti-friction properties under dry conditions of sliding [5]. An attractive feature to be noted in this development, is that shell char is a renewable resource available in large quantities at costs much lower than graphite. In this letter we report the ultrasonic velocity measurements made on cast aluminium alloy-shell char particle composites containing up to 30vol % shell char. These measurements have been examined in the light of recent theoretical formulations on wave propagation in random particle composites. The usefulness of the ultrasonic measurements for nondestructive testing and evaluation of the composites has also been examined. Composites containing up to 30 vol % coconut shell char particles were prepared by conventional casting techniques. The processing, in principle, consists of the melts containing the suspended shell char particles either under gravity or under pressure in suitable permanent cylindrical moulds. Fuller accounts of composite preparation, including particle pre-treatment procedures for promoting wetting between the particles and the matrix, are given elsewhere [5]. For ultrasonic measurements, specimens of 50 mm diameter by 25ram length with plane parallel end faces were machined out of the cylindrical castings. A commercial pulse-echo type of apparatus [6] was used with PZT transducers. Longitudinal velocity measurenents were performed at 2 MHz.

Magnetic layer design considerations for highly durable recording tape

AbstractAmong magnetic recording tapes for such applications as mass storage systems, the antiabrasion properties of the magnetic layer along with storage life are major factors determining magnetic tape life. This paper examines the effect of magnetic layer structural parameters which affect durability and the signal‐to‐noise ratio. Several magnetic tape layer design conditions aimed at improving magnetic tape reliability and recording density are then presented. That is, in order to effect a highly durable binder structure, it is necessary to achieve appropriate mechanical characteristics (tensile strength ≥1 kg/mm2 and elongation at break ≥40%) by crosslinking a large‐matrix, high‐molecular weight polyurethane as well as carefully adjusting the balance of each additive. On the one hand, lapping treatment is effective in improving the SN ratio, with a decrease of up to two‐thirds in surface roughness possible. At the same time, it is found that magnetic pigment content is an important factor limiting durability and that it is a sensitive structural parameter which must be determined based on its inverse relation to the SN ratio. Using a specially developed binder, we demonstrate that a highly durable magnetic tape capable of withstanding more than 108 head scan passes is possible, that the use of lapping treatment can improve the SN ratio by 4 dB, and that a suitable value for the magnetic pigment content is on the order of 68‐72%.