Wear Resistance Of Alumina Research Articles

Wear behaviour of Al-MWCNT composites by varying MWCNTs concentration

The present study illustrates the mechanical and wear behaviour of Al-MWCNT composites by varying MWCNTs concentration (0 %,0.25 %, 0.50 % & 1 %) by weight in composites. These composites were synthesized through sintering in the muffle furnace after mechanical alloying which involved flattening and welding particles to form flake-shaped lamellar particles. The presence of MWCNT lamellas restricted grain growth, creating a 2D aluminium layer between the MWCNTs during sintering. Increasing the MWCNT content in aluminum refined the interlayer thickness of the composites. The compressive strength of Al is increased exponentially with the addition of CNTs. By adding CNTs to aluminium, the maximum strength was reached at 460 MPa in 1% samples, and the compression strength of the aluminium increased by 84 % as well. The sintered composites exhibited higher hardness and its value increased significantly when CNTs were added to the Al composite. The wear resistance of aluminium is substantially increased when CNTs are added, and the maximum wear resistance is achieved when CNTs are added at 0.5 wt%. The addition of CNTs reduced wear resistance, which could be attributed to the decrease in interface adhesion and agglomeration effects of CNTs.

Development of Wear Resistant Aluminum Based Nano-Composite Reinforced With Nano-AlN

Abstract The present study aims at development of nano-AlN reinforced aluminum metal matrix composite through stir casting method. For this commercially pure aluminum (CP-Al) and CP-Al + 2 wt% AlN nano-composite were casted at 760 °C by stir casting method. Both the alloy and the composite were subsequently characterized using optical microscopy and scanning electron microscopy. They were further tested for mechanical properties and dry sliding pin-on-disk wear studies were carried out at three different loads at room temperature at 200 rpm up to a sliding distance of 2 Km. The results indicate good particle dispersion into the matrix and massive grain refinement in the nano-composite. Accordingly, there is an improvement in UTS and 0.2% YS values by more than 100% by keeping ductility unaffected in the composite compared to the base alloy. Grain refinement and strengthening effect of nano-particles are the reasons for this improvement. Moreover, the wear study reflects considerable improvement in wear resistance in the composite at all loads. Suppression of adhesion (at all loads) and plowing abrasion (at 60 N load) are attributed to this improvement in wear resistance in the composite.

Hardness and Wear Properties of Al-TiN Coatings Produced by DC Sputtering

Aluminum is a lightweight material that is commonly used in engine components. However, aluminum's low hardness and wear resistance, requires special treatment before being used as a component. Increasing the hardness and wear resistance of aluminum can be done by coating Titanium Nitride (TiN) with the sputtering method. In this study, the effect of sputtering time on Al-TiN coating on hardness and wear resistance was obtained. The deposition of titanium nitride thin films on aluminum using a gas ratio of Ar: N ((70:30%) with varied treatment times of 30, 60, 90, and 120 minutes. Hardness and wear resistance were observed using Vickers hardness tester and Ogoshi High-Speed Universal. Whereas the morphology of the wear surface was observed by SEM. The result shows that the treatment time of 60 minutes obtained the highest hardness and minimum specific wear rate.

Tribological performance and wear mechanisms of a high-temperature wear-resistant Al-Si/SiAlON composite

High-temperature wear-resistant aluminum alloy matrix composites are of prime importance for the advancement of industries such as aerospace and automobile. For this objective, the SiAlON particle reinforced Al-20Si-5Fe-2Ni alloy matrix composite with outstanding wear resistance and withstanding temperature was developed. The phase, microstructure, and mechanical properties of the composite were investigated. And effects of test temperature on the hardness and tribological behavior at RT–600 °C were examined. The results indicate that the wear resistance of the composite is significantly improved as compared with the matrix. This is primarily attributed to the improved high-temperature hardness, which results from the load-bearing effect and dispersion-strengthening effect with the addition of SiAlON ceramic, and the formation of tribolayer on the worn surface.

The influence of carbon on the microstructure and wear resistance of alumina

AbstractThe influence of carbon as a dopant on grain growth and wear resistance of polycrystalline alumina was evaluated. Carbon was introduced into alumina by sintering in a carbon‐rich environment (graphite furnace under flowing He), and/or by residual carbon from organic binders used during the green body consolidation process. Samples were sintered at 1600°C for 2 h. Doping alumina with carbon resulted in a reduced grain size after sintering, correlated to solute‐drag, and graphite particle‐drag for high concentrations of carbon (~3 wt.%). The material response to abrasive wear was quantified by measuring the sample area cut for a defined time using a diamond wafering saw, as a function of grain size and carbon content. Sintering alumina with carbon resulted in a significant increase in wear resistance, as a result of the reduced grain size.

Microstructural and mechanical characterizations of stir cast aluminum 356–Nb2O5 composite

Stir casting and heat treatment was applied to manufacture wear-resistant aluminum 356 matrix composites with niobium pentoxide particle reinforcement. Regular scattering of matrix phase and uniform distribution of particles were achieved through stirring fully liquid aluminum melt and Nb2O5 mixture. A normal solidification rate and T6 heat treatment guarantied the fine microstructure, low porosity content, minimum particle-free zones, very small primary/secondary dendritic arm spacings, and needle-like Si2Fe2Al9 phase. Composite formation increased the macro/microhardness from 27 to 66.5 and 33 to 88.7 kgf/mm2 for macro- and microhardness, respectively. It also decreased the wear mass loss considerably and improved the fatigue limit and the forming capabilities due to the moderate tensile/bending strength and ductility.

Wear resistant aluminum alloy - B4C composites fabricated by rheo-casting and rolling process

To reveal the formation and wear mechanisms of rheo-formed aluminum alloy - B4C composites, A356 alloy − 10 mass% B4C composite material was fabricated by semi-solid stirring rheo-casting and rolling process. The presence of Al3BC was confirmed by XRD analysis and hinted that chemical bonding formed at interfaces between aluminum matrix and B4C particles. Tensile test results demonstrated that addition of B4C facilitated improving the tensile strength by refining matrix and providing particle strengthening. Failure tests revealed that the failure type of the composite transferred from interfacial debonding to particle cracking with increasing wear load. The wear rate of the composite was approximately 48% lower than that of aluminum alloy under 60 N load. The friction coefficient of the composite under 60 N load also significantly decreased due to formation of B2O3 and H3BO3 as solid lubricants.

Semi-Solid Precision Forming Process of High-Strength and Wear-Resistant Aluminum Matrix Composites

A layered composite structural model with an outer wear-resistant layer of high-silicon aluminum alloy and an inner layer of ultra-high strength aluminum alloy is designed. A scaling brake drum part with layered composite was prepared by semi-solid precision forming process. The effects of process parameters such as casting temperature, specific pressure, solid layer temperature and heattreatment system on the composite interface were investigated. The results show that the casting temperature and solid layer temperature had a great influence on the interface recombination. The high forming specific pressure could effectively restrain the growth of secondary dendritesof the composite, and the proper heat treatment process could improve the morphology of the composite interface. A scaling brake drum component with A390/7050 layered composite structure was well prepared under optimal conditions.

The Influence of Technological Parameters of Cold Gas Dynamic Spraying on Wear Resistance of Aluminum–Carbon Nanofibers Coatings

The Influence of Technological Parameters of Cold Gas Dynamic Spraying on Wear Resistance of Aluminum–Carbon Nanofibers Coatings

Effect of Nb2O5 and MgO/Nb2O5 doping on densification, microstructure and wear resistance of alumina

Abstract In this paper, the influence of Nb2O5 single-doping and MgO/Nb2O5 co-doping on the densification, microstructure and wear resistance of Al2O3 has been investigated. The results show that Nb2O5 single-doping can increase the density of alumina effectively, but excessive Nb2O5 will lead to abnormal grain growth. Comparing with Nb2O5 single-doping, MgO/Nb2O5 co-doping can further increase the density and suppress the abnormal grain growth of the alumina. Meanwhile, the co-doped samples also show much lower wear rates. Typically, when 500 ppm MgO/1000 ppm Nb2O5 co-doped, the alumina ceramics has a minimum wear rate of 0.01‰, which is about 1/5 of the alumina ceramics with 1000 ppm Nb2O5 single-doped. The inhibiting effect of co-doping on abnormal grain growth and the reasons for the decrease of wear rate are also discussed.

High Wear-Resistant Aluminum Matrix Composite Layer Fabricated by MIG Welding with Lateral B4C Powder Injection

In this work, a low-cost technique combining MIG welding and lateral powder injection was developed to fabricate B4C particles-reinforced aluminum matrix composite (AMC) layer on a T6 heat-treated 7075 aluminum alloy (AA7075-T6) substrate. The AMC layer was 6-7 mm thick and well bonded to the substrate. The B4C particles were dispersed throughout the AMC layer with an average content of approximately 7 vol.%. No significant reaction products existed either at the particle–matrix interface or in the Al-matrix. In pin-on-disk dry sliding wear tests against Al2O3 grinding wheels, the AMC layer exhibited excellent wear resistance with volume wear rate approximately 1/10-3/10 that of the quenched AISI 1045 steel and only approximately 2-7% that of the AA7075-T6 alloy under the same wear conditions. A small addition of ceramic particles can greatly improve wear resistance, suggesting that this technique has good prospects for a wide variety of applications.

Tribological Behavior of Al–20Si–5Fe–2Ni Alloy at Elevated Temperatures Under Dry Sliding

Wear-resistant aluminum alloys have enormous potential applications. In this paper, the Al–20Si–5Fe–2Ni alloy was fabricated by hot-pressed sintering, and its dry sliding wear behavior was investigated from 25 °C to 500 °C sliding against Al2O3 ceramic and AISI 52100 steel. The microstructure, phase, high temperature hardness, and worn surface of the sintered alloy were examined. The results indicate that the uniform distribution of Si particles and Al5FeSi intermetallic in the Al matrix contribute to its superior tribological properties. Additionally, the correlation of the tribological behavior of the alloy with the sliding testing conditions was studied, and its wear mechanism was discussed.

Performance of ANFIS Coupled with PSO in Manufacturing Superior Wear Resistant Aluminum Matrix Nano Composites

In this study, ANFIS was combined with PSO in order to optimize the parameters in pressure assisted semi solid processing of A360 aluminum matrix nano composites. ANFIS was utilized to calculate the objective function, which was later minimized using PSO. Combination of EMS semi solid processing and pressure assistance during solidification resulted in improvement of microstructural features and tribological properties. Globular grain structure was formed in the pressure assisted EMS parts. Tribological properties were investigated using pin on disk. It was noted that wear properties of EMS parts were benefited from the refinement of the primary α-Al phase and uniform distribution of the particles. EMS composites showed higher hardness than conventional cast parts, consequently there was a lower real area of contact and therefore lower wear rate. Moreover, hard dispersoid made the virgin alloy plastically constrained and improved their wear resistance.

Effect of Zr addition on the mechanical characteristics and wear resistance of Al grain refined by Ti after extrusion

Aluminum and its alloys are normally grain refined by Ti or Ti+B to transfer their columnar structure during solidification into equiaxed one which improves their mechanical behavior and surface quality. In this paper, the effect of addition of Zr on the metallurgical, and mechanical aspects, hardness, ductility and wear resistance of commercially pure aluminum grain refined by Ti after extrusion is investigated. Zr was added at a level of 0.1% which corresponds to the peretectic limit at the Al-Zr phase diagram. The experimental work was carried out on the specimens after direct extrusion. It was found that addition of Ti resulted in decrease of Al grain size, whereas addition of Zr alone or in the presence of Ti, resulted in reduction of Al grain size. This led to increase of Al hardness. The effect of the addition of Ti or Zr alone resulted almost in the same enhancement of Al mechanical characteristics. As for the strain hardening index,n, increase was obtained when Zr was added alone or in the presence of Ti. Hence pronounced improvement of its formability. Regarding the effect of Zr addition on the wear resistance of aluminum; it was found that at small loads and speeds addition of Ti or Zr or both together resulted in deterioration of its wear resistance whereas at higher loads and speeds resulted in pronounced improvement of its wear resistance. Finally, the available Archard model and the other available models which consider only the mass loss failed to describe the wear mechanism of Al and its micro-alloys because they do not consider the mushrooming effect at the worn end.

Wear-resistant aluminum and chromonickel coatings at the narrow mold walls in continuous-casting machines

To extend the working life of molds in continuous-casting machines, a heat- and wear-resistant layer is formed on the narrow M1 copper walls prior to final repair, by spraying on aluminum and chromonickel coatings. The first step is to determine the coating structure, phase composition, and the hardness and microhardness of the surface layers. A chromonickel coating (thickness 0.5–0.6 mm) is sprayed on the surface of the pair of narrow walls of the thick-walled mold. To obtain the required surface purity, the walls must be ground. Efforts are required to increase the thickness of the chromonickel coating. With a coating thickness greater than 0.8 mm, peeling is possible. Therefore, to increase the strength with which the chromonickel coating is bound to the copper base, we consider the possibility of using an aluminum substrate. Thus, to extend the life of the narrow mold walls in a continuous-casting machine, a chromonickel coating with an aluminum substrate may be applied if bonding of the porous layer with the α phase is ensured or the porosity of the layer is reduced.

Micro/Nanostructure and Tribological Characteristics of Pressureless Sintered Carbon Nanotubes Reinforced Aluminium Matrix Composites

This study reports the manufacture, microstructure, and tribological behaviour of carbon nanotube reinforced aluminium composites against pure aluminium. The specimens were fabricated using powder metallurgy method. The nanotubes in weight percentages of 0.5, 1.0, 1.5, and 2.0 were homogeneously dispersed and mechanically alloyed using a high energy ball milling. The milled powders were cold compacted and then isothermally sintered in air. The density of all samples was measured using Archimedes method and all had a relative density between 92.22% and 97.74%. Vickers hardness increased with increasing CNT fraction up to 1.5 wt% and then reduced. The microstructures and surfaces were investigated using high resolution scanning electron microscope (SEM). The tribological tests showed that the CNT reinforced composites displayed lower wear rate and friction coefficient compared to the pure aluminium under mild wear conditions. However, for severe wear conditions, the CNT reinforced composites exhibited higher friction coefficient and wear rate compared to the pure aluminium. It was also found that the friction and wear behaviour of CNT reinforced composites is significantly dependent on the applied load and there is a critical load beyond which CNTs could have adverse impact on the wear resistance of aluminium.

P005 耐摩耗性特殊Al合金製コンロッドへのかち割り工法の適用条件の検討(メカボケーション学生研究発表セッション)

P005 耐摩耗性特殊Al合金製コンロッドへのかち割り工法の適用条件の検討(メカボケーション学生研究発表セッション)

Influence of Interfacial Reaction on Wear Resistance of Aluminum Alloy/SiC Composites Fabricated by Low Pressure Infiltration Process

Influence of Interfacial Reaction on Wear Resistance of Aluminum Alloy/SiC Composites Fabricated by Low Pressure Infiltration Process

Effect of Heat Treatments on Dry Sliding Wear Resistance of Aluminum –Cupper Alloys.

Effect of Heat Treatments on Dry Sliding Wear Resistance of Aluminum –Cupper Alloys.

Metal nitride coatings by physical vapor deposition (PVD) for a wear resistant aluminum extrusion die.

The purpose of this study is to investigate the friction and wear behaviors of CrN, TiN, CrAlN, and TiAIN coated onto SKD61 for application to Al 7000 series extrusion dies. On the wear test, the experimental parameters are the load and the counter material's temperature. The results showed that the friction coefficient increased with load but decreased with the counter material's temperature, and the friction coefficients of CrN and CrAIN were lower than the friction coefficients of TiAIN and TIN, especially at a higher temperature. The wear track with different coatings identified different wear behaviors; the wear behavior of CrAIN was found to be abrasive, but the wear behavior of TiN, CrN, and TiAIN was adhesive. Therefore, CrAIN showed the least wear loss with a lower friction coefficient and less adhesion with counter materials at the highest range of wear load and temperature. This resulted in the easy formation of aluminum oxide in the wear track and less Al adhesion; moreover during the hard second phase, AIN dispersed in the film during deposition.