Papers by Keyword: Slurry

Abstract: Single crystal diamond is widely used in high-tech fields for its remarkable performance on mechanics, calorifics, optics, acoustics, etc. High-quality diamond surface with small roughness and low scathe are required in these applications. However, the extreme hardness and high chemical inertness of diamond result in severe processing difficulties. Chemical mechanical polishing (CMP) is a promising processing method which can obtain super-smooth and low-damage diamond surface. Oxidant is a key issue for CMP of single crystal diamond. In this study, five different oxidants were used to polish diamond samples. The results indicated that Fenton reagent was an appropriate CMP oxidant and a super-smooth diamond surface of Ra 2.4 nm was achieved by using Fenton reagent in CMP.

Abstract: Hypereutectic Al-Si-Cu alloys which are typical light-weight wear-resistant materials, are required to improve the ductility as well as the strength and wear-resistance for the wider applications. Increase in amounts of primary silicon particles causes the modified wear-resistance of hypereutectic Al-Si-Cu alloys, however, it leads to the poor strength and ductility. It is known that dual phase steels composed of hetero-structure have succeeded to bring contradictory mechanical properties of high strength and ductility concurrently. In order to apply the idea of hetero-structure to hypereutectic Al-Si-Cu alloys for the achievement of high strength and ductility along with wear resistance, ultrasonic irradiation to molten metal during the solidification, which is named sono-solidification, was carried out from its molten state to just above the eutectic temperature. The sono-solidified Al-17Si-4Cu alloy is composed of hetero-structure, that is, hard primary silicon particles, soft non-equilibrium α-Al phase and eutectic region. Rheocasting was performed at just above the eutectic temperature with sono-solidified slurry to shape a disk specimen. After the rheocasting with modified sono-solidified slurry held for 45s at 570^oC, the quantitative optical microscope observation exhibits that the microstructure is composed of 18area% of hard primary silicon particles and 57area% of soft α-Al phase, in contrast there exist only 5area% of primary silicon particles and no α-Al phase rheocast with normally solidified slurry. Hence the tensile tests of T6 treated rheocast specimens with modified sono-solidified slurry exhibit the improved strength and 5% of elongation, regardless of more than 3 times higher amounts of primary silicon particles compared to that rheocast with normally solidified slurry.

Abstract: Nowadays, ceramic foam was widely used in bio-medical as well as engineering field such as thermal insulation and adsorption of environmental pollutants. Ceramic foam made of a porous structure that provides the physical and mechanical properties of both, low specific weight and high thermal fluidity. In this study, the selected starting ceramics powder are titanium dioxide (TiO₂), aluminum oxide (Al₂O₃) and Silver Nitrate (AgNO₃). In general, TiO₂ is very light weight compared to other substance. It is brightness and very high refractive index. On the other hand, Al₂O₃ is responsible for the resistance of metallic aluminum to weathering while AgNO₃ is plays important role as antiseptics. These unique properties of these ceramics has encouraged more study to be implemented on it. Preferred method for the ceramic foam fabrication is via slurry method. In which consists steps of mixing, dipping, pressing, drying and sintering. Three different temperatures of 1200°C, 1250°C and 1300°C, with compositions of 22.5wt% of TiO₂ + 7.5wt% Al₂O₃ + 1.25 wt% AgNO₃ with 2.5wt% of Carbolic methylcelulose (CMC) and 7.5wt% Polyethylene glycol (PEG) are apply in this study. Analysis of the phases, morphology, porosity, density and sringkage were carried out on all samples. From this study, foams of 47.8% to 62.6% porosity using TiO₂ + Al₂O₃ + AgNO₃ were successfully produced. The highest porosity value of 62.61% was fabricated at 1200°C and the highest density value of 2.06% at 1300°C. Thus, it is concluded that the optimal fabrication slurry method parameters of sintering temperature of 1300°C and the compositions of 22.5wt% of TiO₂ + 7.5wt% Al₂O₃ + 1.25wt% AgNO₃ with 2.5 wt% of CMC and 7.5wt% PEG has absorbability of heavy metal and bacteria in pre-treatment process can be develope.

Abstract: Wear by slurry abrasion is very expansive problem that must be taken into consideration while selecting the material for the transportation of slurry through pipeline. Abrasive wear generally occurs when abrasive slurries come in contact with the industrial engineering components or slurry transporting pipes. The abrasive particles carried by slurries eventually remove the material from the encountering surfaces which results in the early failure of the component in service. In present investigation an attempt is made to study the effect of load, slurry concentration, sliding distance on the abrasive wear behaviour of mild steel. The slurry abrasion experiments were carried out using slurry abrasion test apparatus with silica sand slurry. The findings of the present investigation indicate that slurry abrasion volume increased with slurry concentration, load and sliding distance, although the magnitude of increase was different in each case. The SEM observation of worn out surfaces revealed micro ploughing and micro cutting as wear mechanisms.

Abstract: With the developing of integrated circuit(IC) technique, improving of integration level, reducing of feature size and increasing the wafer size, the stringent requirements for global planarization during IC fabrication are raised. During chemical mechanical polishing(CMP) of multilevel interconnect for IC, there are obvious influence of the polishing quality on performances of the device．CMP slurry is one of the important factors of influencing the polishing quality. In this work, the stability of tungsten plug CMP slurry for IC multilevel interconnect was studied. Through experiment, interaction between the components in the CMP slurry was analyzed, and stable slurry with optimized polishing parameters to achieve higher removal rate were defined．

Abstract: In many areas, there are still a development road construction materials, traditionally, often use reinforced concrete, asphalt and other adhesive method to strengthen the low strength of rock and soil anti-freeze expansion coefficient; And now all countries in the world are studying how to use industrial production waste development of new composite materials. One of the most development potential, the production of industrial waste - slime. This paper USES the Russian kazan national construction university experimental methods, in the experiment to improve frost heaving soil physical and mechanical properties of the method for the synthesis of adhesive, based on the feasibility and applicability, environmental assessment of research and analysis, for the use of adhesive put forward a lot of reference value.

Abstract: As to the centrifugal pump for slurry, the effects of solids particles on the performance of the pump have been extensively researched. It is essential to understand the effects of solids on the pump performance well in order to obtain the performance of centrifugal pump for handling slurries. Some existing correlation equations to predict the performance are analyzed and summarized in this paper. A new simple correlation equation to predict the head ratio for pumps handling solids has been developed. The simple equation has been validated by the experiment data published in the related literature. The results by the simple equation are compared with ones available in the literature. The result shows that the simple equation is in good agreement with the experimental data, and it can be used to predict the performance of centrifugal pump for slurry.

Abstract: Reticulated silicon carbide porous ceramics was fabricated through organic foam infiltration process by using silicon carbide slurry prepared from silicon carbide, alumina and clay and other raw materials. The effect of solid content on the viscosity and Zeta potential of the slurry were investigated. The results showed that the viscosity of slurry increased with the increase of the solid content. The absolute value of Zeta potential increased with the increase of pH value of the slurry from acid to alkaline aptitudes, and it became smaller with the further increase of the pH value. The maximum was reached at the pH around 10. The viscosity of slurry in the range of 4000mPas ~ 5000mPas was appropriate to prepare reticulated silicon carbide porous ceramics. The sintered body collapsed or cracked apparently, when the viscosity was too low. On the other hand, the viscosity could not be too high because its hard for slurry to impregnate foam. The performance of the samples coated once and recoated was compared. The porosity of the sample with one layer was higher than that of the samples with two layers. However, the recoating process improved the compressive strength and flexural strength of the reticulated silicon carbide porous ceramic.

Abstract: In this paper, aiming at the Fuyu high angle holes cementing technical issues, in-depth study the quick-setting, high early strength and micro-expansion anti-channeling slurry system. Use this system in Fuyu region high angle holes cementing engineering, the completion of 10 high angle holes were all qualified, 8 of which were quality well, the pass rate of 100% and quality rate of 80%.Solve the difficult problem of the cementation quality and packer formation of the cement sheath, ensure the cementing Quality of Fuyu city high angle wells, which has an important guide and reference on Jilin Oilfield in the future development of the deep horizontal and cementing technology.

Abstract: In this study, we investigate the effect of four types of water reducing agen on fluidity, suspensibility, thixotropy and the particle size of ceramic slurry and analyze the corresponding mechanism. Those water reducing agen include Lignin sulfonate water reducing agent, Sodium metasilicate, naphthalene sulfonate formaldehyde condensate, and the inorganic compound reducing agent. Experiment results shows that the relative molecular mass, the structure of water reducer, the content, and the moisture content of ceramic blank particle can play an important role in the adaptability of both water reducing agen and ceramic slurry. We make a mixed water reducer with lignin sulfonate, sodium metasilicate, and naphthalene sulfonate formaldehyde condensate by the corresponding appropriate mass ratio: 3:2:1. Then we add the mixed water reducing agen by the total dosage of 0.6% into the designed ceramic castable. We find that the performance of the slurry is considerably better improved by the mixed water reducing agen than by either a single one or by the currently commercial inorganic compound reducing agent, such as better improvements in liquidity, the slurry particle size, the mechanical strength of dry body, and the damage strength of porcelain body.