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1.
In the present study, the abrasive wear characteristics of Al 2O 3/PA1010 composite coatings were tested on the turnplate abrasive wear testing machine. Steel 45 (quenched and low-temperature tempered) was used as a reference material. The experimental results showed that when the Al 2O 3 particles have been treated with a silane coupling agent (γ-aminopropyl-triethoxysilane), the abrasive wear resistance of Al 2O 3/PA1010 composite coatings has a good linear relationship with the volume fraction of Al 2O 3 particles in Al 2O 3/PA1010 composite coatings and the linear correlation coefficient is 0.979. Under the experimental conditions, the size of Al 2O 3 particles (40.5-161.0 μm) has little influence on the abrasive wear resistance of Al 2O 3/PA1010 composite coatings. By treating the surface of Al 2O 3 particles with the silane coupling agent, the distribution of Al 2O 3 particles in PA1010 matrix is more homogeneous and the bonding state between Al 2O 3 particles and PA1010 matrix is better. Therefore, the Al 2O 3 particles make the Al 2O 3/PA1010 composite coatings have better abrasive wear resistance than PA1010 coating. The wear resistance of Al 2O 3/PA1010 composite coatings is about 45% compared with that of steel 45. 相似文献
2.
Abrasion wear resistance is very important in many applications and it is not a surprise that there are many laboratory test methods for its determination. In this article, a possibility of the abrasive wear resistance determination with scratch tester, as a relatively easy and quick test method, was analysed and compared with the standard test method for pin abrasion testing (ASTM G 132). Materials used in the tests were: two ferrous-based coatings (deposited on an Al–Si alloy substrate with atmospheric plasma spraying), two aluminium-based composite materials with 10 wt% of Al 2O 3 reinforcements (produced with compocasting technique) and grey cast iron, known as a material with good abrasive wear resistance. Coefficient of friction and wear of the samples were investigated with both abrasion wear test methods and analysed in correlation with their mechanical properties. 相似文献
3.
Nanocomposite coatings can endow a plated surface with various properties such as wear resistance, high-temperature corrosion protection, oxidation resistance, and self-lubrication. This work studies the corrosion and corrosive wear resistance of electroplated nickel nanocomposite coatings on Ti-6Al-4V alloy in a Hank's solution, adding various concentrations of an Al 2O 3 powder in plating solution, with particle diameters of 20–30 nm and 1 μm for comparisons. The experimental results showed that the content of Al 2O 3 incorporated into the electroplated nickel composite coating increased with the concentration of Al 2O 3 powder in the electroplating solution, and increasing the surface hardness, corrosion, and corrosive wear resistance of electroplated nickel micro- and nanocomposite coatings caused smearing of the nodule boundary and elimination of voids in the deposits. The Al 2O 3 nanoparticulates were embedded and distributed more uniformly than the Al 2O 3 microparticulates in the nickel matrix after a heat treatment of 400°C, producing a more continuous and dense coated composite layer on the Ti-6Al-4V substrate. This phenomenon is responsible for the Ni/Al 2O 3 composite coating with superior surface hardness, providing high corrosion resistance and corrosive wear protection to the Ti-6Al-4V alloy substrate in Hank's solution. 相似文献
4.
The methods of atom-force microscopy and measurement of the nanohardness, elasticity modulus, cohesion forces, and friction coefficient with scratch testing (the scratching method) are applied to study the Al 2O 3 oxide coatings produced by magnetron deposition on Al targets. The morphologies of the coatings are compared when they are produced by the reactive synthesis and magnetron target sputtering and application of oxygen ions in high-frequency plasma. The accomplished study of the tribological and mechanical characteristics demonstrates that the resulting coatings possess stronger hardness and elasticity modulus. Application of the oxide coatings reduces the friction coefficient considerably compared with the substrate; the scratch test reveals higher strength and better adhesion to the substrate. Comparative analysis shows that the Al 2O 3 coatings applied to the nanostructural TiN film are 1.5 times harder than the coatings deposited on steel. 相似文献
5.
Materials working in slurries containing seawater and abrasive particles degrade gradually because of the synergic effects of mechanical wear and electrochemical corrosion. In this study, the abrasion–corrosion behaviors of a steel–steel tribopair in an environment with artificial seawater and SiO 2/Al 2O 3 particles were investigated. Corrosion is responsible for surface degradation at low concentrations of SiO 2 particles, whereas abrasion is the primary cause for steel damage at high SiO 2 concentrations. When Al 2O 3 particles were used, abrasion was found to be the dominant factor for material loss at all concentrations. Results from this study indicate that at low concentrations of hard particles, abrasion–corrosion behavior is determined by the properties of particles. 相似文献
6.
Slurry erosion performance of detonation gun (D-gun) spray ceramic coatings (Al 2O 3 and Al 2O 3–13TiO 2) on CF8M steel has been investigated. Slurry collected from an actual hydro power plant was used as the abrasive media in
a high speed erosion test rig. Attempt has been made to study the effect of concentration (ppm), average particle size and
rotational speed on the slurry erosion behaviour of these ceramic-coated steels under different experimental conditions. The
analysis of eroded samples was done using SEM, XRD and stylus profilometry. The slurry erosion performance of the D-gun spray
Al 2O 3–13TiO 2-coated steel has been found to be superior to that of Al 2O 3-coated steel. Both the coatings showed brittle fracture mechanism of material removal during the slurry erosion exposure. 相似文献
7.
A ball cratering test has been used to investigate the abrasive wear of high speed steels with different volume fraction and size of primary carbides. Three different abrasives, SiC, Al 2O 3 and ZrO 2 were used. Wear mechanisms were investigated by scanning electron microscopy (SEM). A good correlation between the hardness of the abrasives and the abrasive wear coefficient was found. Higher abrasive wear resistance was determined for steels containing coarser primary carbides compared to those without or with smaller carbides. The most pronounced difference in abrasive wear resistance was found for Al 2O 3 abrasives. This indicates that in ball cratering the abrasive medium has to be chosen properly, i.e. with a hardness adjusted to those of both primary carbides and martensitic matrix, to obtain results suitable to rank high speed steels with respect to abrasion resistance. 相似文献
8.
During the last decade, the usage of difficult-to-machine materials such as austenitic stainless steels has increased continuously
in various industrial applications. Tools such as blind hole taps, punches, or deep drawing molds are often exposed to severe
wear while machining/forming these materials, mainly due to excessive adhesion and material transfer. On combination with
abrasive wear due to work-hardened wear debris, tool lifetime in these applications is often limited. In this study, ball-on-disc
experiments were carried out with arc-evaporated AlCrN coatings with different Al/(Al + Cr) ratios against Al 2O 3 and austenitic stainless steel balls in ambient atmosphere. Test temperatures of 25, 500, and 700°C were chosen for the hard
Al 2O 3 balls simulating severe abrasive loads, whereas 25, 150, and 250°C were used for the softer stainless steel material to evaluate
the adhesive wear behavior. Characterization of the wear tracks was done by scanning electron microscopy in combination with
energy-dispersive X-ray analysis and optical profilometry. The best abrasive wear resistance during testing against Al 2O 3 was observed for the coating with the highest Al content. In the case of the austenitic stainless steel balls, sticking of
the ball material to the coating surface was the dominating wear mechanism. The influence of test temperature, chemical composition,
and surface roughness was studied in detail. 相似文献
9.
The tribological performance of Al 2O 3/NiCr coating deposited on steel (SM45C) was investigated under lubrication. The parameters of sliding wear consist of normal
load and coating thickness. Test result showed that there was no evidence of an improved bonding strength in the coating.
However, the wear resistance of the Al 2O 3/NiCr coating was significantly greater than that of the Al 2O 3 coating. It was evident that the residual stress for the AI2O3 coating was higher than that of the Al 2O 3/NiCr coating from the scratch test failure of coating. The bond coating played an important role in decreasing the residual
stress. Also, it was found that the residual stress had a notable influence on the wear mechanism. 相似文献
10.
The scratch-adhesion test has been used to monitor the coating-to-substrate adhesion of hard coatings deposited onto steels by two different techniques. In the first instance TiN, TiC and Al 2O 3 coatings were deposited by chemical vapour deposition (CVD). With the CVD TiC and Al 2O 3 coatings, pre-critical stylus load flaking could be observed at the edges of the scratch channel. In contrast, TiN did not display such flaking. Energy dispersive X-ray analysis (EDXA) and Auger electron spectroscopy (AES) were used to investigate this behaviour. In the second example, the initial stage of a continuous plasma nitride-TiN magnetron deposition process was varied to optimize the adhesion of the subsequently deposited TiN topcoat. A suite of characterization techniques including hardness determination, AES, profilometry, and optical cross-sectioning was used to help explain the scratch-adhesion test results. 相似文献
11.
Si-based nano/micro-electromechanical system (NEMS/MEMS) devices with contacting and rubbing structures cannot run reliably due to their poor tribological performance. A thin alumina (Al 2O 3) film is a promising candidate for the protective coating in the applications of NEMS/MEMS devices. In this study, nanotribological behavior of ultra-thin Al 2O 3 films prepared by atomic layer deposition on a Si (100) substrate was investigated in comparison with that of Si (100). X-ray photoelectron spectroscopy was used to determine the composition of Al 2O 3 films. Atomic force microscopy with different tips was employed to measure the scratch resistance, adhesion and friction forces of various samples. The results show that Al 2O 3 films have larger scratch resistance than that of Si (100). In addition, the adhesion and friction forces of Al 2O 3 films are smaller than that of Si (100). Thus, the Al 2O 3 films are capable of a wide application in Si-based NEMS/MEMS devices. The improved tribological performance of Al 2O 3 films is attributed to their hydrophobic properties. 相似文献
12.
We consider the influence of alumina (Al 2O 3) particles on mechanical and tribological properties of aluminum hybrid metal matrix composites (MMC). Various weight fraction of Al 2O 3 (5, 10 and 15%) and constant weight fraction of graphite (5%) were used to fabricate composites by stir casting method. The effect of Al 2O 3 content on hardness, density and specific wear rate is evaluated. A wear test was performed using central composite design matrix on a pin-on disc apparatus at room temperature for constant sliding distance of 1000 m. The sliding speed, load and weight fraction of Al 2O 3 were the process variables. The results show that the hardness and density increase with increase in Al 2O 3 content. From the analysis of variance (ANOVA), load is the dominant factor that affects the specific wear rate of hybrid composites followed by speed and weight fraction of Al 2O 3. Based on desirability approach, the improvement in the wear resistance of the composites became more prominent at high speed, high load and high weight fraction of Al 2O 3. The worn surface of the pin was examined using scanning electron microscope (SEM) which indicates that the wear mechanism of composites is mostly abrasive wear followed by oxide wear. 相似文献
13.
The effect of the sliding speed on friction and wear characteristics of plasma-sprayed ceramic coatings (Al 2O 3-13% TiO 2, ZrO 2-8% Y 2O 3, Al 2O 3-modified) was studied. Plasma-sprayed coatings are not hard and have high layered structure. Abrasion of coatings in the friction pair with steel and bronze counter-bodies occurs through brittle detachment conglomerated regions with low cohesive resistance. The modified coating (Al 2O 3) has the highest wear resistance and the lower coefficient of friction compared to the coatings (Al 2O 3-13% TiO 2, ZrO 2-8% Y 2O 3) in the studied velocity range (0.1–10 mm/s). Laser melting can be used as an efficient way of increasing the tribotechnical properties of plasma-sprayed oxide coatings. 相似文献
14.
In this paper, we describe experimental torch welding 1061 aluminum alloy to T2 copper. The corrosion behavior and performance of Cu/Al brazed joints were systematically investigated. This investigation was conducted using an optical microscope (OM), scanning electron microscope (SEM), energy disperse spectroscopy (EDS) and other methodologies. The results showed that the corrosion resistance of brazed joints was closely associated with Al content in filler metal. The corrosion behavior in 3.5 % NaCI solution belonged to micro-electrochemical corrosion and depended mainly on electrochemical imbalance between different phases. The excessive dissolution of Al atoms led to the occurrence of the corrosion of brazed joints and the corrosion product may be Al(OH)3, Zn(OH)2 and ZnO. It can be also found that an increase of aluminum content controlled largely formation and distribution of α-Al phase and Al2O3 protective film in brazing alloys, resulting in reducing the electrochemical corrosion current density and improving the corrosion resistance and shear strength of the joint. 相似文献
15.
The influence of diameter and content of Al 2O 3 particles on the tribological behaviors under fretting wear mode was investigated. The surface of PEEK composite and steel ball were examined by SEM and EDS, to identify the topography of wear scar and analyze the distribution of chemical elements in the friction counterparts, respectively. It can be found that the filling of Al 2O 3 powder improves the fretting wear resistance of PEEK composite. With the increase of Al 2O 3 diameter, the area of wear scar on specimen increases first and decreases afterward. However, the wear of composites increases monotonically with increasing Al 2O 3 content. Although the filling of 10 wt.% and 200 nm PTFE powder in PEEK makes the lowest wear of all specimens, no synergistic effect was found when Al 2O 3 and PTFE were filled into PEEK composite together. For the friction pair of PEEK composite and steel ball, abrasive wear and adhesive wear dominate the fretting wear mechanism during fretting. Thermal effect plays a very important role during fretting; thus the property of temperature resistance for polymer material would affect the wear degree on the surface of wear scar. 相似文献
16.
In this research, silver and alumina particles were co-deposited within Ni–P matrix to obtain Ni–P–Ag–Al 2O 3 hybrid coating. The structure of coatings was analyzed by X-ray diffraction and the tribological properties of deposits were evaluated by pin on disc tribometer. 3D optical profiler and scanning electron microscopy were used to study wear rate and worn surfaces. The results showed that Ni–P–Ag and Ni–P–Ag–Al 2O 3 coatings have the self-lubrication property and maximum hardness (∼1310 HV) and wear resistance were obtained for Ni–P–Al 2O 3 coating. Also, Ni–P–Ag–Al 2O 3 hybrid nanocomposite coating had higher wear resistance than Ni–P and Ni–P–Ag coatings. Moreover, the best conditions was achieved for heat treated hybrid coating in the concentration of 30 mg/L silver and 150 mg/L alumina in the plating solution. 相似文献
17.
Reinforcing silica particles in the overlay of decorative laminates were found to cause microcracking of Al 2O 3 abrasive grains during the standard test of the National Electrical Manufacturers Association, U.S.A. (NEMA). This lowered the cutting ability of the abrasive paper.When the Al 2O 3 abrasive paper slid on silica-free overlays, the major change to the surface of the abrasive paper was dislodgment of abrasive grains. However, the cutting power of the abrasive paper remained reasonably constant in spite of dislodgment, which was attributed to repeated participation of those grains in the cutting action and subsequent weakening of the strength of the backing resin. 相似文献
18.
The use of metal matrix composite structures in biomedical implants can be a solution for decreasing the amount of degradation products. Thus, the present work aims to investigate the synergism between corrosion and wear on CoCrMo matrix 10% (vol) Al 2O 3 particle reinforced composites in phosphate buffer solution (PBS) at body temperature. Corrosion behavior was investigated by electrochemical impedance spectroscopy and potentiodynamic polarization. Tribocorrosion tests were performed under open circuit potential, as well as under cathodic and anodic potentiostatic conditions using a reciprocating ball-on-plate tribometer. Results suggest that the addition of Al 2O 3 particles did not create a significant effect on corrosion behavior of CoCrMo alloy, however, it increased the wear resistance and decreased the corrosion kinetics when sliding in PBS solution. 相似文献
19.
The paper describes a method of coating combining two different layer types. The first layer is Al 2O 3 produced by plasma spraying with a thickness of around 200 μm which was deposited on a stainless steel substrate. Subsequently, ZrO 2 layers were deposited on to the Al 2O 3 coating by a sol–gel process using a dip coating technique. The dip coating process was repeated in order to see the influence of the number of ZrO 2 layers. Moreover, the effect of annealing temperature was investigated. In order to study their tribological behaviour, the coatings were subjected to micro-scale abrasion, scratch testing and ball-on-disc tests. The result shows that sol–gel ZrO 2 top layers reduce friction and enhance the wear resistance of the coating system. 相似文献
20.
Monolithic B 4C, Al 2O 3/(W,Ti)C and Al 2O 3/TiC/Mo/Ni ceramic composites, which provided a reasonably wide range of mechanical properties and microstructure, were produced to be used as nozzles materials. The erosion wear of the nozzle caused by abrasive particle impact was compared with dry sand blasting by determining the cumulative mass loss of the nozzles made from these materials. Results showed that the hardness of the nozzle material plays an important role with respect to its erosion wear. On the nozzle entry bore section, the B 4C nozzle appears to be entirely brittle in nature with the evidence of large scale-chipping, and exhibited a brittle fracture induced removal process. While the erosion mechanism of Al 2O 3/TiC/Mo/Ni nozzle appeared to be a preferential removal of the metal binder followed by pluck out of the undermined Al 2O 3 and TiC grains under the same test conditions. On the nozzle center bore zone, the B 4C nozzle fails in a highly brittle manner, and there are lots of obvious micro-cracks and small pits located on this area. While the primary wear mechanisms of Al 2O 3/TiC/Mo/Ni nozzle is plowing and micro-cutting by the abrasive particles. Both types of material removal model seem to be occurred for the Al 2O 3/(W,Ti)C nozzle. 相似文献
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