Effect of Phosphorus on Microstructure and Properties of Al-Mg2Si Alloys Subjected to Electromagnetic Stirring

2011 ◽  
Vol 291-294 ◽  
pp. 652-657 ◽  
Author(s):  
Yu Yan Ren ◽  
Ying Min Li

Al-Mg2Si composite has such advantages as low density, high elastic modules, simple manufacture technology and low cost. However, its strength and ductility need to be enhanced. Thus, the alloying element P was added to control the microstructure of Al-Mg2Si alloy and furthermore improve the mechanical properties of the composite. The experimental results show that the microstructure of the Al-Mg2Si alloys subjected to electromagnetic stirring can be significantly refined and the mechanical properties of the alloy get improved due to the addition of phosphorus. It is found that the best modification effect can be achieved when the adding amount of phosphorus is in the range from 0.7% to 1.1% and the holding time is about 15 minutes, and the mechanical properties of the Al-Mg2Si alloys get markedly enhanced.

Author(s):  
Sanjay Sharma ◽  
Deepak Verma

Increasing concern about global warming and depleting petroleum reserves and the high cost of petroleum products had made scientists to focus more on the use of natural fibres such as rice husk, baggase, coconut husk, hemp, sisal, jute, flax, banana etc. Past decade has shown many efforts to develop composites to replace the Petroleum and other non-decaying material products. Reinforcement with natural fibre in composites has recently gained attention due to low cost, easy availability, low density, acceptable, strength full, stiffness, ease of separation, enhanced energy recovery, biodegradability and recyclable in nature. Natural fibre composites are suitable as wood substitutes in the construction sector. All these have excellent physical, thermal and mechanical properties and can be utilized more effectively in the development of composite materials. In this connection, an investigation has been carried using rice husk, a natural fibre abundantly available in India.


2018 ◽  
Vol 25 (6) ◽  
pp. 1039-1058 ◽  
Author(s):  
Sumit Das Lala ◽  
Ashish B. Deoghare ◽  
Sushovan Chatterjee

AbstractThe inherent properties of bio-composites such as biodegradability, environment friendly, low cost of production, high strength and durability make them a suitable replacement to traditional materials such as glass and nylon. Bio-polymers are finding wide applications due to their intrinsic properties such as low density, low thermal conductivity, corrosion resistance and ease of manufacturing complex shapes. This paper aims toward a comprehensive study on polymer bio-composites. The review mainly focuses on types of reinforcements such as natural fibers, seed shells, animal fibers, cellulose, bio-polymers, bio-chemicals and bioceramics which enhance the mechanical properties, such as tensile strength, compressive strength, flexural strength, Young’s modulus and creep behavior, of the composites. The pertinent study carried out in this review explores an enormous potentiality of the composites toward a wide variety of applications.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 252
Author(s):  
Sarah Dine ◽  
Elodie Bernard ◽  
Nathalie Herlin ◽  
Christian Grisolia ◽  
David Tingaud ◽  
...  

Recent studies have shown that low grain sizes are favorable to improve ductility and machinability in tungsten, as well as a resistance to ablation and spallation, which are key properties for the use of this material in a thermonuclear fusion environment (Tokamaks such as ITER). However, as one of the possible incidents during Tokamak operation is the leakage of air or water from the cooling system inside the chamber, resulting in the so-called loss of vacuum accident (LOVA), extensive oxidation may arise on tungsten components, and the use of an alloy with improved oxidation resistance is therefore highly desirable. As current production routes are not suitable for the fabrication of bulk nanostructured tungsten or tungsten alloys samples, we have proposed a new methodology based on powder metallurgy, including the powder synthesis, the densification procedure, and preliminary mechanical testing, which was successfully applied to pure tungsten. A similar study is hereby presented on tungsten-chromium alloys with up to 6 wt.% Cr. Results show that full tungsten densification may be obtained by SPS at a temperature lower than 1600 °C. The resulting morphology strongly depends on the amount of the alloying element, presenting a possible second phase of chromium oxide, but always keeps a partial nanostructure inherited from the synthesized powders. Such microstructure had previously been identified as being favorable to the use of these materials in fusion environments and for improved mechanical properties, including hardness, yield strength and ductility, all of which is confirmed by the present study.


2019 ◽  
Vol 1 (6) ◽  
pp. 503-508
Author(s):  
Tharunkumar N ◽  
Anand G

The present investigation addresses the external strengthening of reinforced concrete (RC) T-beams using jute fiber laminates. An experimental study is mainly carried out to study the change in structural behaviour of RC T-beams using externally wrapped jute fiber laminates, to enhance the shear and flexural capacity of the beams. The effect of pattern and orientation of the strengthening fabric on the shear capacity of the strengthened beams will be examined. RC T-beams with minimum shear reinforcement is designed and then external confinement using jute fiber laminates is carried out using epoxy resin. The layer confinement is executed to study and analyze the behaviour of confined beams with respect to control beam. Experimental results showing the advantage of beam strengthened using the various lay-ups of jute fiber are to be discussed. For all developed composites, experimental results revealed that the tensile properties of the developed composites are strongly dependent on the tensile strength of jute fiber and that the tensile properties of jute fiber are very much defect sensitive. Jute as a natural fiber is eco-friendly, low cost, versatile in textile fields and has moderate mechanical properties, which replaced several synthetic fibers in development of many composite materials. However, the hydrophilic nature of the jute fiber affects the mechanical properties of the developed composites. As a result to arrest crack and improve the strength of beam.


2019 ◽  
Vol 35 (1) ◽  
pp. 200-206
Author(s):  
Mashael Alshabanat

This work aims to develop green linear low-density polyethylene (LLDPE) composites that are commercially viable due to the low cost of the date palm leaflet filler, which is a local renewable resource. The filler was naturally treated with gum arabic solution. FT-IR, XRD, and SEM techniques were used to characterize the samples. The thermal and mechanical properties were measured by TGA, DSC, and tensile testing. The results showed noticeable changes in the properties of the composites compared to those of the original LLDPE sample. TGA revealed that the composite started thermally. The composites started thermally degrading before the original polymer, owing to the degradation of the natural components in the filler. The findings from DSC suggested that the crystallinity was affected. The tensile testing results indicated that the composites were appropriate for applications requiring low tensile strength at break and high Young’s modulus. A comparison of these results with earlier ones exhibited that the basic additives in the polymer may have an effect on the filler performance.


2015 ◽  
Vol 817 ◽  
pp. 545-549 ◽  
Author(s):  
Wen Bin Wang ◽  
Lin Zhang ◽  
Chong Luo ◽  
En Gang Wang

In order to improve the distribution of second phase and performance the Cu-Cr-Zr alloy was processed by solidification under the effect of electromagnetic stirring (EMS) and in situ drawing deformation. Study of Cu-Cr-Zr conductivity and mechanical properties under different deformation strains was also carried out, to analyze the effect of EMS on Cu-Cr-Zr alloys. The experimental results showed that the Cr dendrites tended to be smaller and shorter in Cu-10Cr-0.1Zr alloy solidified with EMS (16Hz, 100A). Since electromagnetic stirring have the role to break dendrite,it’s beneficial to increase the amount of dendrites and decrease the size of dendrites. The tensile strength of Cu-10Cr-0.1Zr wire solidified with EMS was higher than that solidified without EMS.


2019 ◽  
Vol 57 (2) ◽  
pp. 208-214
Author(s):  
Zuzana Mitalova ◽  
Juliana Litecka ◽  
Dusan Mital ◽  
Marta Harnicarova ◽  
Jan Valicek ◽  
...  

The paper deals with destructive testing of �new� group of material - Wood Plastic Composite (in short WPC). WPC emerging from a fusion of two different kinds of components - thermoplastics matrix and natural reinforcement (fibres or flour). Natural fibres offer several advantages - they are renewable, inexpensive, low-density, good isolate a sound and low cost. These components are mixed under the influence of high temperature and then pressed to make various shapes. This material contains cracks localized on the interface between the wood and plastic. These cracks occurred due to inhomogeneity of WPC and affected mechanical properties of final WPC product. The testing of mechanical properties (tensile test and bending test) were determinate in VUHZ Dobra (Ostrava) - following the ISO standards. Significant differences between mechanical properties after testing were caused by non-perfect encapsulation between components and non-homogeneity of materials.


2020 ◽  
Vol 9 (1) ◽  
pp. 2304-2310

Little consume energy materials have recently received increased attention as an ecological and sustainable alternative. We propose to study a building approach with raw earth (adobe) combined with plant fibers. The latter used as reinforcement in composite materials have specific competitive mechanical properties compared to those of synthetic fibers (glass, carbon, ...) and are an environmentally friendly alternative to these fibers because of their low cost, low density, biodegradability and availability. We describe adobe stabilization and reinforcement process with treated rush fibers. We introduce our approach to formulate an earth mortar allowing the making of blocks of adobe, intended for the construction of works such as walls, arches and domes.


2021 ◽  
Vol 1 (1) ◽  
pp. 1-3
Author(s):  
Ramesh Gomasa

Foamed concrete is a special type of concrete and it can be used widely in construction of reinforced concrete structures. this study is very helpful for understanding about foamed concrete and mechanical properties of foamed concrete. Lot of researches are going on concrete material and finally we got foamed concrete. It has lot of advantages compared to conventional concrete. Fluidity and Flowability is very good in the foam concrete. It can be used for low cost of construction of structures. It has high properties and advantages compared to conventional concrete. Manufacturing and Production of poly urethane is very simple and easy. because of their low density it can be used for low-cost construction works. Weight of the concrete is also less compared to other conventional concrete.


2006 ◽  
Vol 519-521 ◽  
pp. 1251-1256
Author(s):  
X. Fang ◽  
G. Shao ◽  
Z. Fan

Al-Fe compounds are usually present in the as-cast microstructure of Al-alloys as large needles or plates. As such, they have a detrimental effect on the mechanical properties of Al-alloys containing Fe, either as an impurity element or as an alloying addition. However, Fe-containing Al-alloys also offer attractive physical properties, such as improved stiffness, wear resistance and thermal resistance. If the needle and plate morphology of the Al-Fe compounds can be modified to a more compact morphology, with refined particle size and uniform distribution, the mechanical properties of Al-Fe based Al-alloys can be substantially improved, and therefore, they will find wider applications in many engineering sectors. A new semisolid metal processing technology, rheodiecasting (RDC), has been developed for production of Al-alloy components with high integrity. The RDC process innovatively combines the dispersive mixing power of the twin-screw mechanism, for the creation of high quality semisolid slurry, with the high efficiency, low cost nature of the high-pressure diecasting (HPDC) process for component shaping. In this paper, we present our experimental results on the effects of intensive melt shearing on the size and morphology of Al-Fe compounds in A380 alloys, with different levels of Fe additions. The experimental results have shown that intensive melt shearing during solidification can effectively change the particle shape from the usual needles and plates, to an equiaxed morphology. Samples which have undergone with melt shearing, exhibit much improved strength and ductility compared to those with the same level of Fe addition, but without exposure to melt shearing.


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