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Fundamental Investigation on the Polishing Aspheric Elements with Doughnut-Shaped MCF Slurry
摘要： Previous researches have confirmed that MCF (magnetic compound fluid) slurry shows outstanding performance in the Nano-precision polishing of flat surfaces and V-grooves. However, no investigations have been conducted on the polishing of aspheric surfaces using MCF slurry. In this work, a novel method employing a doughnut-shaped MCF polishing tool and a 6-DOF manipulator has been proposed for the aspheric surface polishing. The time consumption for forming stable polishing tool and its final appearance are investigated. Flat aluminum alloy workpieces that can be considered as a kind of aspheric elements with infinite curve radius were adopted in the investigation of the polished forces under variable parameters. As a typical experimental result, with MCF3 slurry, 2.5ml volume of supplied slurry and work gap 3.5 mm, the surface roughness Ra decreases from 125nm to almost 10nm after 90 min polishing, confirming that the proposed method has the potential to polish aspheric surfaces.
关键词： Aspheric surface,Manipulator,Polishing,MCF slurry
更新于2025-09-23 15:23:52
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Effect of multi stage abrasive slurry jet polishing on surface generation in glass
摘要： The polishing process is used to produce a smooth surface with a required geometrical figure for the optical component. The abrasive slurry jet polishing process is one of the non-traditional polishing process, which is used to polish freeform optics with the nano-level surface finish. In the abrasive slurry jet polishing process, the saturation in surface roughness is observed with a jet exposure time or polishing time. Once the saturation limit is reached a further reduction in surface roughness without the modification of processing conditions and the size of the abrasive particles is not possible. Hence to achieve the required surface roughness a different polishing strategy has to be adapted. In this work, an attempt was carried out to yield a considerable reduction in surface roughness using a multistage polishing concept. In this concept, the impact angle, the traverse speed of the nozzle, the type and size of the abrasive particle were changed after the first stage of polishing. The surface generation has been studied by measuring the surface roughness at each stage of polishing, and the Scanning Electron Microscope (SEM) analyses have been done to understand the changes in surface texture, after polishing. From the experiments, the large size Al2O3 particle in the first stage of polishing and then small size Al2O3 particle in the remaining stages of polishing yields a considerable reduction in surface roughness. The combination of parameters with the type and size of the abrasive particles to be used to achieve the required surface characteristics were demonstrated. Thus, the multistage polishing concept can be floated as a viable strategy to achieve a high reduction in surface roughness on the optical component.
关键词： Abrasive,Particle size,Traverse speed,Slurry,Multistage Polishing,Glass
更新于2025-09-23 15:23:52
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Characterization of CMP Slurries Using Densitometry and Refractive Index Measurements
摘要： We investigated the possibility of employing refractive index (RI) measurements for inline incoming slurry control at the point of use (POU), as an alternative to the widespread densitometry method. As such, it became necessary to determine if RI could detect smaller changes in slurry composition and, therefore, provide a tighter control. Three industrially-relevant silica-based slurries, namely, Fujimi PL-7106, Klebosol 1501-50, and CMC W7801, were characterized using both densitometry and RI measurements. Initial solutions of the three slurries were prepared and increasingly small amounts of ultrapurified water (UPW) were added to study the change in slurry properties. Results showed that both density and RI decreased linearly with the addition of water for all three slurries, with the 1501-50 being the most sensitive to water addition. A linear correlation between the two properties was found, with R2 values that exceeded 0.95 in all cases. Furthermore, the approximate limit of detection of both metrology tools was estimated based on the slope of the fitting line and resolution. When compared to densitometry, RI was found to be the far superior method for detecting smaller changes in water concentration.
关键词： semiconductor technology,slurry characterization,in-line monitoring and control,chemical mechanical planarization
更新于2025-09-23 15:22:29
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Exergy and energy analysis of wavy tubes photovoltaic-thermal systems using microencapsulated PCM nano-slurry coolant fluid
摘要： To develop a more efficient water-cooled photovoltaic-thermal system, energy and exergy analysis of a photovoltaic-thermal system with wavy tubes are investigated numerically using different coolant fluids. A comparison between the straight tube and wavy tubes is conducted for various wavelengths and wave amplitudes. The geometrical parameters of the wavy tubes as well as the velocity of the coolant fluid are examined. Besides, the consequences of coolant fluid including water, Ag/water nanofluid, microencapsulated phase change material slurry, and also a new type of cooling fluid called microencapsulated phase change material nano-slurry are studied. The results show that the electrical, thermal, and exergy efficiencies of the photovoltaic-thermal module enhance by using the wavy tubes compared with the corresponding straight tubes. By declining wavelength in a constant wavelength/amplitude, the heat absorbed by the heat transfer fluid raises. For the best configuration, the primary and exergy efficiencies of the module increase by 6.06% and 4.25%, respectively, for the wavy tubes system compared with those for the straight unit. Furthermore, in both configurations, by increasing the inlet velocity, the overall performance of the photovoltaic-thermal module increases due to a higher heat transfer rate. The results also reveal that among different types of cooling fluids, the microencapsulated phase change material nano-slurry has higher performance in terms of both energy and exergy efficiencies due to having higher thermal conductivity and heat capacity. By employing the wavy tube and the novel proposed coolant fluid, the primary and exergy efficiencies increase in comparison with a typical photovoltaic-thermal module.
关键词： Energy,Microencapsulated phase change material slurry,Wavy tube,Nanofluid,Photovoltaic-thermal module,Exergy
更新于2025-09-23 15:21:01
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Separation of Si and SiC from Photovoltaic Industry Waste. Recycling of SiC in Production of Cu2O-SiC Powder
摘要： Silicon ingot cutting process generates slurry waste which mainly contains lubricant oil, silicon and silicon carbide particles. In this study, slurry waste was the subject of a primary decantation which served to obtain two different effluents namely dark sludge (DS) and dark liquid (DL). Deoiling treatment of DS and DL using acetone was carried out. The resulting powders were first leached by nitric acid to remove heavy metals and then washed by distilled water to separate Si and SiC. Scanning electron microscopy (SEM) coupled to energy dispersive x-ray spectrometry (EDXS) and x-ray diffraction (XRD) show a successful separation of Si and SiC particles. As reuse of SiC-rich powder, a Cu2O-SiC composite was synthesized by electroless plating process under experimental controlled parameters.
关键词： Composite,Silicon,Silicon carbide,Electroless plating,Slurry waste
更新于2025-09-23 15:19:57
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Dry Magnetic Separation on the Recovery of Metal Fragments from Kerf Slurry Waste Produced during the Manufacture of Photovoltaic Solar Cells
摘要： In the interest of reducing the cost of photovoltaic production while preserving the environment, a sawing rejection treatment was carried out by recovering the metals with an efficiency estimated to be 96%. To achieve this outcome, first, the sawing rejection was washed with acetone to dissolve the polyethylene glycol. It was then dried in an oven at 70 °C to obtain a slurry powder. This later, powder has undergone a dry magnetic separation under different electric current intensity to recover metals. The metal-containing phase has been characterized by the X-ray diffractometer and the scanning electron microscope. Finally, a simulation on the recovery of metal fragments in the slurry generated during the manufacture of photovoltaic briquettes.
关键词： Metals,Slurry,Dry magnetic separation,Photovoltaic cell,Polyethylene glycol (PEG),Scanning electron microscopy (SEM)
更新于2025-09-23 15:19:57
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[ASME ASME 2014 8th International Conference on Energy Sustainability collocated with the ASME 2014 12th International Conference on Fuel Cell Science, Engineering and Technology - Boston, Massachusetts, USA (Monday 30 June 2014)] Volume 1: Combined Energy Cycles, CHP, CCHP, and Smart Grids; Concentrating Solar Power, Solar Thermochemistry and Thermal Energy Storage; Geothermal, Ocean, and Emerging Energy Technologies; Hydrogen Energy Technologies; Low/Zero Emission Power Plants and Carbon Sequestration; Photovoltaics; Wind Energy Systems and Technologies - Magnesium Hydride Slurry — A Better Answer to Hydrogen Storage
摘要： Hydrogen has many properties that make it an attractive energy storage medium for a sustainable future. But hydrogen is also difficult to store safely and cheaply. By storing hydrogen in an oil-based slurry with powdered magnesium hydride, cheap and safe hydrogen storage can be realized. This paper describes the characteristics and benefits of cycling hydrogen in and out of magnesium hydride slurry. Based on our experience with magnesium hydride slurry, we have performed a study to evaluate the cost effectiveness of applying bulk hydrogen storage, using magnesium hydride slurry, in a baseload wind power system that we will also discuss. This study concludes that a 150 MW baseload wind power system would produce an Internal Rate of Return (IRR) of 10% with an electric price of $0.088/kWh. The costs and performance characteristics of this power plant are described.
关键词： electricity storage,energy storage,hydrogen storage,magnesium hydride slurry,baseload wind farm
更新于2025-09-19 17:15:36
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Performance optimization of a photovoltaic/thermal collector using microencapsulated phase change slurry
摘要： In a photovoltaic/thermal (PV/T) collector, a portion of absorbed solar energy is transformed into electrical energy, and the remaining part is transformed into thermal energy. Increasing waste heat collection and energy conversion rates are important to improve the performance of the PV/T collector. The utilization of microencapsulated phase change slurry (MPCS) in a PV/T collector to cool photovoltaic modules is an effective way, and electrical and thermal performances of the collector are improved. To investigate influences of operating parameters on performances of PV/T collector, numerical simulation is put into effect to analyze influences of the mass fraction of MPCS on the collector performance. The influences of MPCS mass flow rate and collector channel height on collector performances are also studied. When the flow rate is 0.005 kg/s and the channel height is 0.010 m, the PV/T collector obtains the best net efficiency with a MPCS mass concentration of 20 wt%. But electrical efficiency difference between 15 and 20 wt% is not obvious. With the growth in mass fraction, PV temperature drops more and more slowly because outlet fluid has not fully melt. Take PV/T collector performances into consideration, 15 wt% MPCS is a better choice to cool photovoltaic modules.
关键词： microencapsulated phase change slurry,photovoltaic/thermal collector,electrical and thermal performances,energy conversion efficiency
更新于2025-09-12 10:27:22
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Materials Science and Technology of Optical Fabrication || Surface Roughness
摘要： Because it influences optical-scatter losses and downstream laser modulation [1], the surface roughness of an optical-glass component is an important parameter for many optical systems (including lasers and telescopes). During optical polishing, a number of interactions between the workpiece, polishing slurry, and pad may influence the resulting workpiece roughness at different spatial scale lengths. The phenomena affecting large spatial scale length (>1 mm) on the workpiece (i.e. surface figure) are described in Chapter 2 (see Figure 2.1). By contrast, in this chapter, the phenomena and process parameters affecting short spatial scale lengths (<1 mm) (i.e., surface roughness from AFM2 scale roughness to μ-roughness) are described (see Figure 1.8). Fine-scale roughness, typically measured by atomic force microscopy (AFM), is referred to as AFM1 (≤5 μm) and AFM2 roughness (≤50 μm), as represented on the right of the plot. Roughness at this scale is influenced by parameters such as the single-particle removal function, Beilby layer properties, slurry particle size distribution (PSD), pad topography, pad mechanical properties, and slurry particle redeposition. The next higher spatial scale length (the micrometer to millimeter range, known as micro- or μ-roughness), is usually measured by white-light interferometry (Figure 1.8). μ-Roughness is affected not only by the smaller spatial-scale length phenomena given above, but also by factors governing slurry-interface interactions, such as the spatial distribution of slurry particles present at the interface. These parameters and phenomena are listed Figure 4.1, consisting of a schematic of the workpiece–lap interface at the spatial scale length of interest that influences the final polished surface roughness. Figure 4.1 provides a valuable outline for this chapter.
关键词： Optical Polishing,Slurry PSD,Pad Topography,AFM,μ-Roughness,Surface Roughness
更新于2025-09-04 15:30:14