scholarly journals Physical-Mechanical Properties of Cupola Slag Cement Paste

2021 ◽  
Vol 11 (15) ◽  
pp. 7029
Author(s):  
Carlos Thomas ◽  
José Sainz-Aja ◽  
Israel Sosa ◽  
Jesús Setién ◽  
Juan A. Polanco ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Circular Economy ◽  
Setting Time ◽  
Casting Process ◽  
Industrial Sector ◽  
Sulphate Attack ◽  
Experimental Campaign ◽  
High Consumption ◽  
Superior Mechanical Properties ◽  
Environmental Savings

The high consumption of natural resources in the industrial sector makes it necessary to implement measures that enable the reuse of the waste generated, seeking to achieve circular economy. This work assesses the viability of an alternative to the use of CEM III B 32.5 R cement in mortars for the internal coating of centrifugally spun cast iron pipes for water piping. The proposal is to reuse the slag generated in the casting process after being finely ground, as an addition mixed with CEM I 52.5 R cement, which is basically Portland clinker. In order to analyse this possibility, an extensive experimental campaign was carried out, including the analysis of the cupola slag (micro-structural and chemical composition, leachates, setting time, vitrification, puzzolanicity and resistance to sulphate) and regarding the mortars (workability and mechanical properties). The experimental programme has shown that the optimum substitution is achieved with a replacement percentage of 20% of the cement, with which similar workability, superior mechanical properties and guaranteed resistance to sulphate attack are obtained. In addition, both economic and environmental savings are achieved by not having to transport or landfill the waste. In addition, the new cement is cheaper than the cement currently used.

Casting Process and Simulation of K19 Cylinder Block

2014 ◽  
Vol 602-605 ◽  
pp. 311-315
Author(s):  
Yi Chen ◽  
Gang Yang ◽  
Yi Yang ◽  
Kang Sheng Wang ◽  
Chen Guang Lu
Keyword(s):  
Mechanical Properties ◽  
Casting Process ◽  
Cylinder Block ◽  
Shrinkage Cavity ◽  
High Quality ◽  
Actual Experiment ◽  
Engine Cylinder ◽  
Numerical Software ◽  
Superior Mechanical Properties ◽  
Simulation Results

Cylinder blocks are the most important parts of engine, and their qualities will fundamentally determine the efficiency of engine. In this work, the casting process of K19 engine cylinder block was studied. A casting process was designed and assessed by the numerical software MAGMA to produce cylinder block castings. An actual experiment of casting was carried out and the mechanical properties of the casting were examined. The simulation results show the liquid metal smoothly fills the casting mold and no shrinkage cavity and porosity are formed in the castings. The cylinder block produced by the actual experiment exhibits superior mechanical properties to common ones, which proves the casting process designed is suitable for producing high quality cylinder block castings. The research shows that numerical simulation can provide very useful guidance for the production of castings

Metallic Nanoneedles Arrays for TEM Sample Preparation “Lift-Out”

2012 ◽  
Author(s):  
Romaneh Jalilian ◽  
David Mudd ◽  
Neil Torrez ◽  
Jose Rivera ◽  
Mehdi M. Yazdanpanah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Sample Preparation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam System ◽  
Transmission Electron ◽  
Nanoneedle Array ◽  
Superior Mechanical Properties ◽  
And Performance

Abstract The sample preparation for transmission electron microscope can be done using a method known as "lift-out". This paper demonstrates a method of using a silver-gallium nanoneedle array for a quicker sharpening process of tungsten probes with better sample viewing, covering the fabrication steps and performance of needle-tipped probes for lift-out process. First, an array of high aspect ratio silver-gallium nanoneedles was fabricated and coated to improve their conductivity and strength. Then, the nanoneedles were welded to a regular tungsten probe in the focused ion beam system at the desired angle, and used as a sharp probe for lift-out. The paper demonstrates the superior mechanical properties of crystalline silver-gallium metallic nanoneedles. Finally, a weldless lift-out process is described whereby a nano-fork gripper was fabricated by attaching two nanoneedles to a tungsten probe.

scholarly journals Effects of Steel Fiber Percentage and Aspect Ratios on Fresh and Harden Properties of Ultra-High Performance Fiber

2021 ◽  
Vol 2 (3) ◽  
pp. 501-515
Author(s):  
Rajib Kumar Biswas ◽  
Farabi Bin Ahmed ◽  
Md. Ehsanul Haque ◽  
Afra Anam Provasha ◽  
Zahid Hasan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
High Performance ◽  
Steel Fiber ◽  
Setting Time ◽  
Fiber Reinforced Concrete ◽  
Future Research ◽  
Manufacturing Cost ◽  
Aspect Ratios ◽  
High Performance Fiber

Steel fibers and their aspect ratios are important parameters that have significant influence on the mechanical properties of ultrahigh-performance fiber-reinforced concrete (UHPFRC). Steel fiber dosage also significantly contributes to the initial manufacturing cost of UHPFRC. This study presents a comprehensive literature review of the effects of steel fiber percentages and aspect ratios on the setting time, workability, and mechanical properties of UHPFRC. It was evident that (1) an increase in steel fiber dosage and aspect ratio negatively impacted workability, owing to the interlocking between fibers; (2) compressive strength was positively influenced by the steel fiber dosage and aspect ratio; and (3) a faster loading rate significantly improved the mechanical properties. There were also some shortcomings in the measurement method for setting time. Lastly, this research highlights current issues for future research. The findings of the study are useful for practicing engineers to understand the distinctive characteristics of UHPFRC.

scholarly journals Composite Material of PDMS with Interchangeable Transmittance: Study of Optical, Mechanical Properties and Wettability

2021 ◽  
Vol 5 (4) ◽  
pp. 110
Author(s):  
Flaminio Sales ◽  
Andrews Souza ◽  
Ronaldo Ariati ◽  
Verônica Noronha ◽  
Elder Giovanetti ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Room Temperature ◽  
Casting Process ◽  
Optical Characteristics ◽  
Smart Devices ◽  
Superhydrophobic Coating ◽  
Gravity Casting ◽  
High Flexibility ◽  
Physical And Chemical

Polydimethylsiloxane (PDMS) is a polymer that has attracted the attention of researchers due to its unique properties such as transparency, biocompatibility, high flexibility, and physical and chemical stability. In addition, PDMS modification and combination with other materials can expand its range of applications. For instance, the ability to perform superhydrophobic coating allows for the manufacture of lenses. However, many of these processes are complex and expensive. One of the most promising modifications, which consists of the development of an interchangeable coating, capable of changing its optical characteristics according to some stimuli, has been underexplored. Thus, we report an experimental study of the mechanical and optical properties and wettability of pure PDMS and of two PDMS composites with the addition of 1% paraffin or beeswax using a gravity casting process. The composites’ tensile strength and hardness were lower when compared with pure PDMS. However, the contact angle was increased, reaching the highest values when using the paraffin additive. Additionally, these composites have shown interesting results for the spectrophotometry tests, i.e., the material changed its optical characteristics when heated, going from opaque at room temperature to transparent, with transmittance around 75%, at 70 °C. As a result, these materials have great potential for use in smart devices, such as sensors, due to its ability to change its transparency at high temperatures.

scholarly journals An Integrated Approach to Convert Lignocellulosic and Wool Residues into Balanced Fertilisers

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 497
Author(s):  
Filippo Marchelli ◽  
Giorgio Rovero ◽  
Massimo Curti ◽  
Elisabetta Arato ◽  
Barbara Bosio ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Renewable Energy ◽  
Circular Economy ◽  
Integrated Approach ◽  
Lignocellulosic Residues ◽  
Biomass Waste ◽  
Slow Pyrolysis ◽  
C And N ◽  
Water Hydrolysis ◽  
Conversion Technologies

Valorising biomass waste and producing renewable energy or materials is the aim of several conversion technologies. In this work, we consider two residues from different production chains: lignocellulosic residues from agriculture and wool residues from sheep husbandry. These materials are produced in large quantities, and their disposal is often costly and challenging for farmers. For their valorisation, we focus on slow pyrolysis for the former and water hydrolysis for the latter, concisely presenting the main literature related to these two processes. Pyrolysis produces the C-rich biochar, suitable for soil amending. Hydrolysis produces a N-rich fertiliser. We demonstrate how these two processes could be fruitfully integrated, as their products can be flexibly mixed to produce fertilisers. This solution would allow the achievement of balanced and tuneable ratios between C and N and the enhancement of the mechanical properties. We propose scenarios for this combined valorisation and for its coupling with other industries. As a result, biomass waste would be returned to the field, following the principles of circular economy.

scholarly journals Utilization of Solid Waste from Brick Industry and Hydrated Lime in Self-Compacting Cement Pastes

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1109
Author(s):  
Mati Ullah Shah ◽  
Muhammad Usman ◽  
Muhammad Usman Hanif ◽  
Iqra Naseem ◽  
Sara Farooq
Keyword(s):  
Mechanical Properties ◽  
Solid Waste ◽  
Manufacturing Industry ◽  
Setting Time ◽  
Hydrated Lime ◽  
Pozzolanic Reaction ◽  
Early Age ◽  
Cement Pastes ◽  
Brick Powder ◽  
High Degree

The huge amount of solid waste from the brick manufacturing industry can be used as a cement replacement. However, replacement exceeding 10% causes a reduction in strength due to the slowing of the pozzolanic reaction. Therefore, in this study, the pozzolanic potential of brick waste is enhanced using ultrafine brick powder with hydrated lime (HL). A total of six self-compacting paste mixes were studied. HL 2.5% by weight of binder was added in two formulations: 10% and 20% of waste burnt brick powder (WBBP), to activate the pozzolanic reaction. An increase in the water demand and setting time was observed by increasing the replacement percentage of WBBP. It was found that the mechanical properties of mixes containing 5% and 10% WBBP performed better than the control mix, while the mechanical properties of the mixes containing 20% WBBP were found to be almost equal to the control mix at 90 days. The addition of HL enhanced the early-age strength. Furthermore, WBBP formulations endorsed improvements in both durability and rheological properties, complemented by reduced early-age shrinkage. Overall, it was found that brick waste in ultrafine size has a very high degree of pozzolanic potential and can be effectively utilized as a supplementary cementitious material.

scholarly journals Mechanical Properties of Al Matrix Composite Enhanced by In Situ Formed SiC, MgAl2O4, and MgO via Casting Process

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1767
Author(s):  
Yuhong Jiao ◽  
Jianfeng Zhu ◽  
Xuelin Li ◽  
Chunjie Shi ◽  
Bo Lu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Matrix Composite ◽  
Compression Strength ◽  
Casting Process ◽  
Al Alloy ◽  
Pyrolysis Process ◽  
Alloy Matrix ◽  
Al Matrix Composite ◽  
Al Matrix

Al matrix composite, reinforced with the in situ synthesized 3C–SiC, MgAl2O4, and MgO grains, was produced via the casting process using phenolic resin pyrolysis products in flash mode. The contents and microstructure of the composites’ fracture characteristics were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties were tested by universal testing machine. Owing to the strong propulsion formed in turbulent flow in the pyrolysis process, nano-ceramic grains were formed in the resin pyrolysis process and simultaneously were homogeneously scattered in the alloy matrix. Thermodynamic calculation supported that the gas products, as carbon and oxygen sources, had a different chemical activity on in situ growth. In addition, ceramic (3C–SiC, MgAl2O4, and MgO) grains have discrepant contents. Resin pyrolysis in the molten alloy decreased oxide slag but increased pores in the alloy matrix. Tensile strength (142.6 ± 3.5 MPa) had no change due to the cooperative action of increased pores and fine grains; the bending and compression strength was increasing under increased contents of ceramic grains; the maximum bending strength was 378.2 MPa in 1.5% resin-added samples; and the maximum compression strength was 299.4 MPa. Lath-shaped Si was the primary effect factor of mechanical properties. The failure mechanism was controlled by transcrystalline rupture mechanism. We explain that the effects of the ceramic grains formed in the hot process at the condition of the resin exist in mold or other accessory materials. Meanwhile, a novel ceramic-reinforced Al matrix was provided. The organic gas was an excellent source of carbon, nitrogen, and oxygen to in situ ceramic grains in Al alloy.

Sign in / Sign up

Export Citation Format

Share Document