Papers by Keyword: Metal Particles

Abstract: Metallurgical Industry slowly moves towards wider utilization of complex ore minerals. Reduction behavior of complex crystalline structures can hardly be interpreted applying kinetic modeling adopted for pure oxides. The quantitative mathematical analysis of the metal particles forming during solid state reduction of a complex mineral has been suggested. The analysis with 95% reliability showed that during solid phase reduction of dunite at 1300 °C for 60 min about 360 particles with an average size about 0.62 mm formed from the total area S = 20880 mm. Such an approach could be useful for development of sophisticated kinetic models applied for reduction of a low-grade complex ore.

Abstract: This research paper presents the analysis of the superficial layer wear of the moving metallic components in a screw compressor, depending on the presence of metal particles in the oil resulted from friction, wear and fatigue processes. The data presented are useful for the analysis of the structural modifications that occur and develop during the operation of a screw compressor, with the possibility to predict a failure. The study of the structural changes can be made by various nondestructive testing methods, namely by analyzing the oil at certain time intervals/hours of operation of the compressor

Abstract: This study presents an analysis of various size metal particle waste (MP) influences on Portland cement (PC) paste hydration course, concrete sample structure densification during hardening and physical-mechanical properties. Investigations have shown that MP filler accelerates maximum heat release rate in PC pastes. MP intensifies structure development in the early phase, but slows it down in later PC hydration period. After 28-days of hardening the compressive strength of the concrete samples without MP filler is about 20% higher than of samples with MP. When in concrete composition microsilica and MP fillers are used together, compressive strength of concrete sample composition is up to 50% higher than of samples with MP filler only.

Abstract: This study presents an application of Hall Effect sensor to assess the viscosity of industrial lubricant by using reference metal particles with the dimension ranging from 1 µm to 100 µm and the mass ranging from 0.1 g to 1 g as the essential modules of the developed system. Hall Effect sensor is a small electronic component which is easy for installing, analyzing, and processing due to electrical output generated. Moreover, the cost of this developed method is lower than other means of viscosity tests. At present, there are several studies on viscosity and quality tests of industrial lubricants such as Ultrasonic measurement of viscosity of liquids [1], Photoacoustic measurement of liquid viscosity [2], Measurement of magnetic viscosity in NdFeB [3], A viscosity and density meter with a magnetically suspended rotor [4], Capacitive sensor [5], IR-Absorption [6], and Optical fiber sensing [7]. In this study, the measurement methodology was considered only the lubricant viscosity at the temperature of 26 °C and then compared the results to the viscosity classification which is the reference of lubricant characteristic. Moreover, the lubricant types namely SAE 15W-40, SAE 20W-50 and ISO VG 100 were selected as the case studies.

Abstract: An experimental facility is built up to investigate the abrasive wear behavior of EMC particles. The parameters explored include particle impacting velocity and impacting angle. The results show that the erosion rate depends on both the particle impacting velocity and impacting angle. A higher velocity will cause more erosion whereas a smaller impacting angle will cause more erosion, especially at higher impacting velocities. Furthermore, the morphology of the eroded particles is irregular in shape and a smaller impacting angle will result in a larger dimension of the eroded particles.

Abstract: Ag and Ni spherical fine powders were continuously produced by carrying out an aerosol process in a mass nanopowder production apparatus. The particles size, particle morphology, crystal phases and crystallinity of the as-prepared powders were characterized by a scanning electron microscope (SEM) and X-ray diffraction (XRD). The particles were nonaggregated and they exhibited a spherical morphology with a narrow size distribution. The average sizes of Ag and Ni particles were 500 nm and 700 nm, respectively. The crystallinity of the as-prepared powders was high. The XRD patterns showed that the crystal phases of the as-prepared powders were the same as those of their respective metals.