Showing 4 results for Wear Resistance
Akhlaghi F., Zahedi H., Sharifi M.,
Volume 1, Issue 2 (6-2004)
Abstract
In this study different volume fractions of SiC particles of various sizes were introduced into the semisolid A356 aluminum alloy by a mechanical stirrer. Then the slurry was poured into a permanent die of certain dimensions either when the metal alloy was partially solid (semisolid-semisolid or SS route) or after reheating to above the liquidus temperature of the alloy (semisolid-liquid or SL route). Both the SS and SL composite samples were solution-treated at 520°C for 8 hours followed by quenching in water at room temperature. Microstructural characterization studies have been conducted on both the SL and SS samples to quantify the effects of the size andcontent of the SiC particles as well as the solutionizing treatment on the morphology and size ofthe eutectic silicon particles and the matrix grain (globule) size. The results were rationalized in terms of the different nucleation, fragmentation, spherodization and coarsening events, which had taken place during the processing of these composites. Finally the impact of these microstructural features in improving the wear properties of the composites has been discussed.
A. Poladi, M. Zandrahimi,
Volume 5, Issue 3 (9-2008)
Abstract
Abstract: Austenitic stainless steels exhibit a low hardness and weak tribological properties. The
wear behaviour of austenitic stainless steel AISI 316 was evaluated through the pin on disc
tribological method. For investigating the effect of wear on the changes in microstructure and
resistance to wear, optical microscopy and scanning electron microscope were used. The hardness
of the worn surfaces was measured with a micro-hardness tester. Worn surfaces were analyzed
through X-ray diffraction. Results showed that with increasing the sliding distance and applied
load, the austenite phase partially transformed to ά martensite, and there was no trace of ε phase
detected. Due to the formation of probably hard and strong martensite phase, as the sliding
distance and applied load increased, the hardness and the wear resistance of the material was
increased. Wear mechanism was on the base of delamination and abrasion.
M. Akbarzadeh, A. Shafyei, H. R. Salimijazi,
Volume 12, Issue 1 (3-2015)
Abstract
In the present study, CrN, TiN and (Ti, Cr)N coatings were deposited on D6 tool steel substrates. Physical and mechanical properties of coatings such as microstructure, thickness, phase composition, and hardness were evaluated. Phase compositions were studies by X-ray diffraction method. Mechanical properties were determined by nano-indentation technique. The friction and wear behaviour of the coatings were investigated using ball-on-disc tests under normal loads of 5, 7 and 9 N at sliding distance of 500 m, at room temperature. Scanning electron microscope equipped with energy dispersive spectroscopy, optical microscope, and 2D/3D profilometry were utilized to investigate the microstructures and wear mechanisms. Wear test results clarified that the wear resistance of (Ti, Cr)N and TiN coatings was better than that of CrN coating. The wear resistance of the (Ti, Cr)N coatings was related to the Ti content in the coatings and reduced by decreasing the Ti content. The dominant wear mechanisms were characterized to be abrasive and tribochemical wear
Mohadeseh Karimi, Mohammad Hossein Enayati, Fatemehsadat Sayyedan,
Volume 21, Issue 0 (3-2024)
Abstract
The aim of this study was to optimize the values of current density and carbide concentration in electrodeposition process of Ni-Fe(Si-Ti)C nanocomposite coating on the AISI 304 stainless steel. The optimal current density in each electrolyte was determined using scanning electron microscope (SEM) images and energy-dispersive spectroscopy (EDS) analysis. Corrosion behavior and wear resistance of the optimized coatings were examined by TOEFL polarization test in 3.5 wt.% NaCl solution and ball-on-disk apparatus, respectively. The values of 30 mA/cm2 and 10 mA/cm2 were obtained to be the optimal current densities for electrolytes containing 6 g/L and 12-18 g/L double carbide, respectively. Electrochemical measurements declared that the corrosion rate decreased from 0.0829×10-5 mA/cm2 to 0.0208×10-5 mA/cm2 with increasing the concentration of carbide in the electrolyte from 6 g/L to 18 g/L. Moreover, the friction coefficient of the substrate was found to be significantly greater than that of the coated samples.
