Percorrer por autor "Fathipour, Zahra"
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- Effect of binder on oxidation properties of tungsten carbides: A review by a Conceptual Classification ApproachPublication . Fathipour, Zahra; Hadi, Morteza; Maleki, Mohammad Reza; Fernandes, Filipe; Fernandes, FilipeThis study presents a conceptual classification scheme to review the literature on improving the oxidation resistance of tungsten carbide by modifying the binder. The first parts of the article are dedicated to the specification of the databases, the search method, and the description of the criteria chosen to classify the articles. Then, the data collected are presented in statistical graphs according to the proposed classification scheme. The data analyzed show that most of the significant improvements in oxidation resistance are achieved with advanced production processes, especially HIP and SPS, which eliminate porosity to a very high degree. In addition, statistical studies showed that the use of new replacement binders, Ni3Al, Fe–based alloys, FeAl, and Al2O3, improved the oxidation properties in 75–100% of cases. Meanwhile, the use of high–entropy alloys (HEAs) as cermet binders may be the subject of future research for oxidation, given the recently published results of good mechanical properties.
- Improvement of Surface Properties and Wear Resistance of Selective Laser Melting-Fabricated Inconel 625 Alloy by Ultrasonic Nanocrystal Surface Modification for Demanding ApplicationsPublication . Fernandes, Filipe; Fathipour, Zahra; Hadi, Morteza; Bayat, Omidnconel 625 alloy is widely utilized in the production of components for demanding industries. This study investigates the effect of ultrasonic nanocrystal surface modification (UNSM) on the surface properties and wear resistance of Inconel 625 alloy produced by selective laser melting (SLM). Specifically, it focused on analyzing the effect of UNSM on the microstructure, hardness, surface roughness, coefficient of friction and essentially wear resistance of the alloy. The results showed that the microstructure formed by SLM, characterized by relatively large melt pools, was modified by UNSM to a depth of approximately 10 to 15 microns, resulting in a new microstructure composed of deformed grains without changing the chemical composition. Surface hardness increased by over 63% after UNSM treatment. In addition, the surface roughness initially induced by the SLM process was reduced by more than 90%, resulting in a tenfold reduction in the coefficient of friction. Wear path analysis showed that while the abrasive wear mechanism of the alloy remained unchanged, the UNSM treated samples exhibited increased debris production and more frequent delamination due to reduced workability. The alterations in surface properties, including reduced crystallite size, increased lattice strain, grain refinement, and decreased surface area, have been identified as key contributors to the enhanced hardness and wear resistance of the alloy following UNSM treatment.
