scholarly journals Influence of Nano-Silica in Al6061 Composites on Mechanical and Material Properties prepared through Powder Metallurgy

2021 ◽  
Author(s):  
Naveenkumar Votarikari ◽  
N. Kishore Nath ◽  
Poosa Ramesh Babu
Keyword(s):  
Powder Metallurgy ◽  
Material Characterization ◽  
Base Alloy ◽  
Mesoporous Structure ◽  
Strengthening Mechanism ◽  
Silica Content ◽  
Milling Process ◽  
Nano Silica ◽  
Preparation Methods ◽  
Compaction Processes

Abstract The influence of composites preparation methods in the aerospace industry has evolved quite new challenges achieving better and desired properties. In this context, this work deals with the preparation of nano silica-based composite through the powder metallurgy technique. The composites prepared were tested for material characterization with morphological, X-Ray diffraction, and mechanical characterization with hardness, tensile strength, density, and porosity tests. The results revealed that the nano-silica has interfacial interaction with aluminum alloy. The strength of Al6061 nano-silica composite has the effect of sintering and compaction processes. Crystallization of Al6061 composite has been influenced by sintering time for nano-silica reinforcement. A compound was formed during the ball milling process during the blending of Al6061 and nano-silica powders was examined and detailed through material characterization. It revealed the structure as a mesoporous structure which created a route for better-impregnated bearing material. Al6061 nano-silica impregnated bearing with porous structure holds the lubricating fluid which is serving the purpose of self-lubrication and self-cooling by dissipating the heat generated during the running conditions. The strengthening mechanism like the Orowan effect and dislocation density strengthening enhanced the process and revealed the effect on nano-silica content. The wettability of silica was improved through binder in PM and the preheating process of powders. Hardness incremented up to 21% of base alloy through the PM technique.

UV-Curable Organic-Inorganic Hybrid Films Based on Epoxynorbornene Linseed Oils

2011 ◽  
Vol 217-218 ◽  
pp. 294-299
Author(s):  
Jian Yun He ◽  
Jin Ping Xiong ◽  
Bing Qian Xia
Keyword(s):  
Linseed Oil ◽  
Silica Content ◽  
Coating Properties ◽  
Hybrid Films ◽  
Nano Silica ◽  
Pencil Hardness ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Silica Coatings ◽  
Wetting Properties

Epoxynorbornene linseed oil (ENLO) is a new kind of epoxide from renewable sources. An UV-curable organic/inorganic hybrid films using epoxynorbornene linseed oils (ENLO) and surface treated nano-silica were formulated. The mechanical properties，thermal properties and coating properties of the ENLO /silica coatings were evaluated as the function of nano-silica content. The results indicated that after incorporating the nano-silica, the strength, modulus and glass transition temperature of the hybrid films enhanced, while the elongation at break decreased. The nano-silica also improved the hybrid coating properties such as pencil hardness, solvent resistance and surface wetting properties. The morphology observation of the films by atomic force microscopy (AFM) showed that the average silica particle size was ~ 70 nm and the particles were well-dispersed in the organic phase.

scholarly journals Preparation of 5-Flurouracil Loaded Microspheres

2017 ◽  
Vol 6 (3) ◽  
pp. 185
Author(s):  
Chen Hong Dan ◽  
Yin Jing Bo ◽  
Chen Xue Si ◽  
Luo Kun ◽  
Cao Tian
Keyword(s):  
Spherical Surface ◽  
Silica Content ◽  
High Yield ◽  
Lower Amount ◽  
Water Evaporation ◽  
Nano Silica ◽  
Water Emulsion ◽  
Drug Content ◽  
Oil In Water ◽  
Oil In Water Emulsion

Polylactide (PLA) is a kind of biodegradable and biocompatible material. In recent years, polylactide (PLA) and its copolymers have received significant attention from researchers. 5-Fluorouracil (5-Fu) is an antimetabolite of the pyrimidine analog type and is widely used for cancer treatment. As many other kinds of hydrophilic medicines, 5-Fu is difficult to be encapsulated by a water-in-oil-in-water emulsion solvent evaporation technique and the drug content is affected by the volume of the internal phase the increase in which resultes in a decrease in the yield of microspheres. In this study, 5-Fu loaded PLA microspheres which has quite high yield were prepared by a particular oil-in-water evaporation method. During the process of microspheres preparation, nano-silica was used in order to achieve high drug content. The size and morphology of the microspheres were observed by the scanning electron microscope (SEM). According to the results, these microspheres have smooth, spherical surface structure, with no apparent evidence of collapsing which can ensure the even release of the drug. Their size depends on the concentration of dispersed phase and gelatin and the size of nano-silica particles. The nano-silica content was determined by thermogravimetry analyzer (TGA) and by a spectrophotometer, the 5-Fu content in the microspheres could be calculated. It was shown that the PLA microspheres containing lower amount of nano-silica have higher ability to incorporate 5-Fu.

Sliding wear behaviour of Al-Si alloy–fly ash composites produced by powder metallurgy technique

2017 ◽  
Vol 69 (2) ◽  
pp. 241-247 ◽  
Author(s):  
H. Siddhi Jailani ◽  
A. Rajadurai ◽  
B. Mohan ◽  
T. Sornakumar
Keyword(s):  
Cast Iron ◽  
Fly Ash ◽  
Powder Metallurgy ◽  
Alloy Powder ◽  
Base Alloy ◽  
Wear Behaviour ◽  
Damping Capacity ◽  
Powder Metallurgy Technique ◽  
Sliding Speed ◽  
Content Type

Purpose Metal matrix composites (MMCs) are commonly used in many aerospace and industrial applications. MMCs possess significantly improved properties including high specific strength, specific modulus, damping capacity and good wear resistance compared to unreinforced alloys. The purpose of this paper is to describe the tribological studies of Al-Si alloy–fly ash composites manufactured using powder metallurgy technique. Design/methodology/approach Al-Si (12 Wt.%) alloy–fly ash composites were developed using powder metallurgy technique. Al-Si alloy powder was used as matrix material, and the fly ash was used as reinforcement. The particle size of Al-Si alloy powder was in the range of 75-300 μm, and the fly ash was in the range of 1-15 μm. The friction and wear characteristics of the composites were studied using a pin-on-disc set up. The test specimen was mated against cast iron disc, and the tests were conducted with the loads of 10, 20 and 30 N, sliding speeds of 0.5, 1 and 1.5 m/s for a sliding distance of 2,000 m. Findings The effects of load and sliding speed on tribological properties of the base alloy and Al-Si alloy–fly ash composites pins on sliding with cast iron disc are evaluated. The wear rate of Al-Si alloy–fly ash composites is lower than that of base alloy, and it increases with increasing load and sliding speed. The coefficient of friction of Al-Si alloy–fly ash composites is increased as compared with base alloy. Practical implications The development of Al-Si alloy–fly ash composites produced by powder metallurgy technique will modernize the automobile and other industries because near net shape at low cost and good mechanical properties are obtained. Originality/value There are few papers available on the development and tribological studies of Al-Si alloy–fly ash composites produced by powder metallurgy technique.

scholarly journals Recent Progress in Biochar-Based Photocatalysts for Wastewater Treatment: Synthesis, Mechanisms, and Applications

2020 ◽  
Vol 10 (3) ◽  
pp. 1019 ◽  
Author(s):  
Jiali Cui ◽  
Feng Zhang ◽  
Hongyan Li ◽  
Jianguo Cui ◽  
Yatao Ren ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Low Cost ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
Preparation Methods ◽  
In Situ Methods ◽  
Low Toxicity ◽  
Rich Material ◽  
Underlying Mechanisms ◽  
Pyrolysis Of Biomass

Biochar (BC) is a carbon-rich material produced from pyrolysis of biomass. In addition to its low toxicity, environmental compatibility, and low cost, BC has the desired advantages of well-developed mesoporous structure and abundant surface functional groups. In recent years, BC-based photocatalysts (BCPs) have played a significant role in many environmental fields. In this paper, we highlight the current progress and several exciting results of BCPs by focusing on their synthesis, characterization, mechanisms, and applications in wastewater treatment. Details on various preparation methods include sol–gel, hydrothermal/solvothermal, ultrasound, calcination, and in situ methods are summarized and discussed. The underlying mechanisms and the applications of BCPs for different semiconductors are reviewed. Furthermore, some future trends and potentials are outlined.

Effects of SiO2 Particles in Mechanical Properties of Iron Composite

2013 ◽  
Vol 465-466 ◽  
pp. 886-890
Author(s):  
Adibah Amir ◽  
Othman Mamat
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Fine Particles ◽  
Sintering Temperature ◽  
Silica Particles ◽  
Milling Process ◽  
Powder Metallurgy Technique ◽  
Temperature Changes ◽  
Different Temperatures

Tronohs raw sand was converted into fine silica particles via a series of milling process. Addition of these fine particles into iron composite was found to modify its mechanical properties. The composite was prepared using powder metallurgy technique with varying percentage of silica particles; 5, 10, 15, 20 and 25wt%. The composites were sintered at three different temperatures; 1000° C, 1100° C and 1200° C to find the most suitable sintering temperature. Changes in density and hardness were observed. The results showed that composite consist of 20wt% silica particles and sintered at 1100° C exhibits best improvement.

scholarly journals Effect of Nano-Silica on Consolidation and Permeability Properties of Lateritic Soil

2020 ◽  
Vol 5 (1) ◽  
pp. 60-72
Author(s):  
J. Ochepo ◽  
I. M. Kanyi
Keyword(s):  
Silica Content ◽  
Lateritic Soil ◽  
Compression Index ◽  
Nano Silica ◽  
Coefficient Of Consolidation ◽  
Consolidation Pressure ◽  
Volume Compressibility ◽  
Curing Period ◽  
Definite Trend ◽  
Recompression Index

A reddish-brown lateritic soil obtained from Zaria; Nigeria was treated with up to 2.5% nano-silica. Consolidation properties (i.e. Pre-consolidation pressure, compression index, coefficient of volume compressibility and coefficient of consolidation) of treated specimens were assessed using one dimensional consolidation test. The permeability property of treated soil was also evaluated. The results obtained showed that the pre-consolidation pressure generally increased with increasing percentage of nano-silica content and curing time. The compression index (Cc) increased steadily with higher percentage of nano-silica contents up to 2.5% treatment for 7 and 14 days of curing, but decreased after 28 days curing period. The recompression index (Cr) on the other hand generally increased with increase percentage of nano-silica content and curing period. The coefficient of volume compressibility (Mv) did not follow any definite trend, but at 2.5% nano-silica content, the Mv decreased for all curing periods considered. The coefficient of consolidation (Cv) also, did not give a definite trend with increase in nano-silica content, suggesting that increasing the amount of nano-silica content in the soil has little or no impact on the time rate of settlement. The coefficient of permeability (k) decreased as the soil was treated with nano-silica especially beyond loading pressure of 40kN/m2. This study showed that nano-silica (up to 2.5%) can be used to stabilize lateritic soil to improve its consolidation properties.

Influence of Nano Silica Addition on the Behavior of Concrete and Its Impact on Corrosion Resistance

2018 ◽  
Vol 15 (2) ◽  
pp. 530-536 ◽  
Author(s):  
R. Vandhiyan ◽  
E. B. Perumal Pillai
Keyword(s):  
Corrosion Resistance ◽  
Water Demand ◽  
Silica Content ◽  
Hardened Concrete ◽  
Nano Silica ◽  
Concrete Technology ◽  
Split Tensile Strength ◽  
Accelerated Corrosion ◽  
New Material ◽  
Experimental Values

Nano materials in concrete technology can lead to structures with improved quality and better lifecycle cost. Nano Silica is an aspiring material that can change the performance of concrete in many ways. Nano Silica being a new material requires a lot of study to understand the behavior of the concrete composite with Nano Silica. In this investigation Nano Silica was added in four different proportions as 0.5 wt%, 1 wt%, 1.5 wt% and 2 wt% of cement, into the concrete mix to study its performance. The mixture was tested for its consistency to understand the water demand and workability. It was observed that the water demand increased with increase in Nano Silica content and superplasticizer can be utilized to improve the workability without increasing the water to cement (W/C) ratios. The hardened concrete displayed enhancement in compressive strength, flexural strength and split tensile strength when Nano Silica was used. The best results were seen when 1.5 wt% Nano silica was added. The corrosion resistance property was studied applying impressed current technique, where the current consumption is allowed to increase with time. The Nano Silica improves the pore structure of the concrete, this leads to improved corrosion resistance in concrete with increase in Nano Silica content. The theoretical and experimental values of mass loss due to corrosion matched only after 80 hours of accelerated corrosion for normal concrete and 60 hours for enhanced concrete.

Evaluating The Effects of Micro and Nano Size of Silica Filler on Asphalt Cement Properties

2020 ◽  
Vol 38 (12A) ◽  
pp. 1832-1841
Author(s):  
Hussein H. Zghair ◽  
Hasan H. Joni ◽  
Maan S. Hassan
Keyword(s):  
Rheological Properties ◽  
Asphalt Binder ◽  
Silica Content ◽  
Asphalt Binders ◽  
Nano Silica ◽  
Silica Powder ◽  
Asphalt Cement ◽  
Main Challenge ◽  
Silica Filler ◽  
Nano Size

This research study examines the practicability of using micro and nano size silica to improve the asphalt characteristics. Asphalt cement penetration grade of (60 /70) was prepared using (0%, 2%, 4% and 6%) of silica filler by weight of asphalt and investigated in terms of the softening point, penetration, and penetration index, viscosity, and ductility values. To modify the asphalt binder, the silica powder was mixed by a mechanical blender set at (2000) rpm at a mixing temperature of 140°C. However, the main challenge is an agglomeration of nano-silica powder which can reduce the ductility of nano silica modified binder. Therefore, this paper studies the efficiency of mixing period to obtain a homogeneous composite binder while alleviating the agglomeration issue. To do so, the effect of periods of mixing ranged between (30 to 60) minutes were examined on characteristics of modified asphalt binders. Overall, the addition of silica filler has an encouraging impact on the asphalt binder rheological properties. Also, the ductility value decreases with the addition of nano-silica content, attributed to the huge surface area and degree of agglomeration.  Furthermore, results exhibited that 6% of micro silica powder and 4 % of nano silica powder were reasonable to develop the rheological properties.

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