scholarly journals Characterisation of Aluminium Matrix Syntactic Foams under Static and Dynamic Loading

2011 ◽  
Vol 82 ◽  
pp. 142-147 ◽  
Author(s):  
Mohamed Altenaiji ◽  
Graham K. Schleyer ◽  
Yo Yang Zhao

Development of a lightweight, strong and energy-absorbing material that has potential application for the protection of vehicles and occupants against impact and blast, is a difficult challenge facing the materials community. Aluminium matrix syntactic foams will be investigated as a possible core material as part of a multi-layered protection system for military vehicles. Aluminium matrix syntactic foams are composite materials consisting of an aluminium matrix implanted with hollow or porous ceramic particles. This paper investigates the mechanical properties of aluminium matrix syntactic foam with different sizes of ceramic micro-spheres and different grades of aluminium, fabricated by the pressure infiltration method. The static crushing behaviour of the foam was investigated under two test conditions using an Instron 4505 machine. Results are compared and discussed. The dynamic compressive response was investigated using a drop-weight impact test machine. It was found that the particle size of the ceramic micro-spheres and the grade of the aluminium metal have a significant effect on the energy absorption capacity of the material. The compressive strength of the syntactic foam was found to increase with increasing compressive strength of the metal matrix.

2018 ◽  
Vol 280 ◽  
pp. 301-307
Author(s):  
Z. Zakaria ◽  
C.Y. Yao

This research focuses on the effect of rejected nitrile butadiene rubber (rNBR) gloves particles reinforced epoxy macrospheres (EM) on the physical properties and compressive stress of syntactic foam. Adding rNBR particles on the surface of macrospheres can increase the energy absorption as a result of improving the compressive properties of syntactic foam. Three types of macrospheres have been produced for the fabrication of syntactic foam, namely EM without rNBR, 1-layer rNBR-EM and 2-layer rNBR-EM. The results showed that increased rNBR particles layer on macrospheres has increased the wall thickness, and reduced the radius ratio of macrospheres as well as increased the density of syntactic foams. The compressive strength and modulus of syntactic foam with 2-rNBR-EM increased compared to the syntactic foams of 1-rNBR-EM and EM without rNBR. In addition, the toughness of the 2-rNBR-EM increased compared to the syntactic foams of 1-rNBR-EM and EM without rNBR.


Author(s):  
Nikhil Gupta ◽  
Eyassu Woldesenbet

Use of syntactic foam as core material in the sandwich structured composites is increasing due to its higher compressive strength, damage tolerance and low moisture absorption compared to the open cell structured foams. Extensive microscopic examination of the syntactic foams tested under compressive and three-point bending conditions is undertaken in this study. The aim of the investigation is to determine the local fracture mode and correlate it with the microscopic structure of the material. Local stress states are identified in the material based on the microscopic fracture features. Syntactic foam tested in the study has resin to microballoons ratio of 1.52 by weight. Compression tests were conducted on the syntactic foam specimens having two different aspect rations, which were 0.4 and 0.91. Three-point bend tests were conducted on the sandwich structures containing syntactic foam as core material and glass fabric as the skin material.


2011 ◽  
Vol 321 ◽  
pp. 7-10 ◽  
Author(s):  
Zhuo Chen ◽  
Zhi Xiong Huang ◽  
Yan Qin ◽  
Min Xian Shi ◽  
Qi Lin Mei ◽  
...  

In this work, syntactic foams made of microballoons having same wall thickness ratio but with different particle size was prepared. Microballoons of three size distribution ranges were selected .The property of the syntactic foams were studied by quasi-static compression test. The experimental results show the microballoons size doesn’t influent the mechanical properties of the syntactic foam significantly. The failure mode of the syntactic foams was also studied in this work.


2016 ◽  
Vol 674 ◽  
pp. 35-40 ◽  
Author(s):  
Andrej Shishkin ◽  
Viktor Mironov ◽  
Vjacheslav Zemchenkov ◽  
Maksim Antonov ◽  
Irina Hussainova

This paper addresses an innovative syntactic foam produced out of metal powder (Fe), fly ash cenospheres (CS) and clay ceramic syntactic foams composite material (CM). Due to the low density of CS (bulk density - 0.38 g/cm3), the average density of these foams is about 2.6-2.9 g/cm3. It was found that CS undergoes phase transformation during thermal treatment at a temperature of 1200°C. Microstructural observations reveal a uniform distribution of CS and Fe particles in the composite. Compressive strength, and friction coefficient of obtained Fe/CS CM are in the range between 149 - 344 MPa and 0.15 - 1.1, respectively. Dependence of compressive strength on firing temperature is demonstrated exhibiting the maximum at 344 MPa; however, dependence of coefficient of friction on a material properties, obtained at different firing temperature exhibits the minimum value of 0.15 at the firing temperature of 1150 °C. The obtained syntactic form was shown to be a candidate for wear resistant applications.


2012 ◽  
Vol 729 ◽  
pp. 68-73 ◽  
Author(s):  
Imre Norbert Orbulov ◽  
János Ginsztler ◽  
Peter Kun

The most promising process for metal matrix syntactic foam (MMSF) production is pressure infiltration. In case if it can be advanced to die casting the cost of the MMSFs will drop significantly. The first step on this road is to characterize the kinetics of the pressure infiltration with respect to infiltration pressure and time. Experimental infiltration equipment was built and many preliminary tests were performed on the AlSi12 + SLG system. The load bearing capacity is also important, therefore the compressive behaviour of MMSFs were investigated. According to the results engineering factors (matrix material, size of the microballoons, applied heat treatment, temperature of the tests) have significant effects on the compressive properties.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Dung D. Luong ◽  
Vasanth Chakravarthy Shunmugasamy ◽  
Oliver M. Strbik III ◽  
Nikhil Gupta

Polyurethane resins and foams are finding extensive applications. Seat cushions and covers in automobiles are examples of these materials. In the present work, hollow alumina particles are used as fillers in polyurethane resin to develop closed-cell syntactic foams. The fabricated syntactic foams are tested for compressive properties at quasistatic and high strain rates. Strain rate sensitivity is an important concern for automotive applications due to the possibility of crash at high speeds. Both the polyurethane resin and the syntactic foam show strain rate sensitivity in compressive strength. It is observed that the compressive strength increases with strain rate. The energy absorbed up to 10% strain in the quasistatic regime is 400% higher for the syntactic foam in comparison to that of neat resin at the same strain rate.


1999 ◽  
Vol 18 (14) ◽  
pp. 1347-1357 ◽  
Author(s):  
Nikhil Gupta ◽  
S. Sankaran

Sandwich structures, especially those with honeycomb and grid structures as the core material, are very commonly employed in aircraft structures. There is an increasing use of closed-pore rigid syntactic foams as core materials in sandwich constructions because they possess a number of favourable properties. The syntactic foams, owing to their structure and formation, behave differently under compression compared to other traditionally used core materials. In the present study, therefore, syntactic foam core sandwich constructions are evaluated for their behaviour under compression in both edgewise and flatwise orientations. Further, the work characterises the relative performance of two sets of sandwich materials, one containing glass-epoxy and the other, glass/carbon hybrid-epoxy skins. As non-standard geometry test specimens were involved, only a comparative evaluation was contemplated in this approach. The experiments indicate that the nature of the reinforcement fabric in the skin has a bearing on the test results in edgewise orientation. Thus, the tendency towards initiation of vertical crack in the central plane of the core material, which is a typical fracture event in this kind of material, was found to occur after a delay for the specimens containing the glass fabric in the skin. Attempts are made to establish the correlation between observations made on the test specimen visually during the course of testing and the post-compression microscopic examinations of the fracture features.


2017 ◽  
Vol 52 (7) ◽  
pp. 971-980 ◽  
Author(s):  
Kerrick R Dando ◽  
David R Salem

Syntactic foams comprising glass microballoons have gained considerable attention over the past several years due to mechanical and thermal properties that are advantageous for use as a core material in naval and aerospace applications. Recent advancements in the production of thermoplastic microballoon syntactic foams have allowed for an increase in microballoon volume fraction (up to 0.9 volume fraction), with correspondingly lower densities but reduced mechanical properties. In this work, carbon nanofibers and halloysite nanotubes were incorporated in thermoplastic microballoon-based syntactic foam to enhance the mechanical properties and the relative effects of these two nanoscale reinforcements were compared. X-ray micro-computed tomography was employed to analyze the microstructure of the materials produced, and scanning electron microscopy was used to assess the dispersion of nano-additives within the resin. Compressive strength and modulus enhancements as large as 180% and 250% respectively were achieved with a 0.25 wt% addition of carbon nanofiber and increases of 165% and 244% respectively were achieved with a 0.5 wt% addition of halloysite nanotube. Tensile strength and modulus enhancements as large as 110% and 165% respectively were achieved with a 0.125 wt% addition of carbon nanofiber and increases of 133% and 173% respectively were achieved with a 0.125 wt% addition of halloysite nanotube.


2016 ◽  
Vol 9 (2) ◽  
pp. 120-128
Author(s):  
Haspiadi Haspiadi ◽  
Kurniawaty Kurniawaty

Research of  the utilization solid waste of palm oil fuel ash from boiler as row materials  for manufacturing light concrete brick has been conducted. The main objective of this study is to investigate the potential use solid waste of palm oil fuel ash from palm oil mill boilers as row materials for manufacturing light concrete brick has recently attracted for an alternative environmentally sustainable application. In this study, light concrete brick made with various proportions of palm oil fuel ash from palm oil mill boilers and sand were fabricated and studied under laboratory scales. Percentage of palm oil fuel ash of 0% as a control,  10%, 20%, 30%, 40%, 50%, 60%, replacement  sand, wheras others materials such as Portland cement, lime, gypsum, foaming agent and aluminium with the numbers constant. The quality of light concreate brick   were applied followed by the compressive strength test, density and water absorption capacity. The study discovered that the compressive strength for all composition meet the recommended value to light structural of 6.89 MPa as prescribed in SNI 03-3449-2002. In the same manner density of light concrete brick for all proportion under the maximum density recommended value of 1400 Kg/m3 according to SNI 03-3449-2002. While water absorption capacity of increased by the increasing use of ashes. Therefore, palm oil fuel ash from boiler can be used as raw material for the light concrete brick which is  environmental friendly because using solid waste and also an alternative handling solid waste.ABSTRAKPenelitian pemanfaatan limbah padat abu cangkang dan serat kelapa sawit dari boiler sebagai bahan baku pembuatan bata beton ringan telah dilakukan. Tujuan dari penelitian ini adalah pemanfaatan limbah padat abu boiler berbahan bakar cangkang dan serat sebagai bahan pembuatan bata beton ringan sebagai salah satu alternatif pengelolaan lingkungan yang bekelanjutan. Dalam penelitian ini, bata beton ringan dibuat dengan berbagai komposisi abu boiler dan pasir yang diproduksi dalam  skala laboratorium. Persentase dari abu berturut-turut 0% sebagai kontrol, 10%, 20%, 30%, 40%, 50% dan 60% mensubtitusi pasir, sedangkan bahan lain yaitu semen, kapur, gypsum,  foaming  agent serta aluminium pasta dengan jumlah tetap. Mutu bata beton ringan yang diujikan adalah kuat tekan, bobot jenis dan daya serap air. Hasil penelitian menunjukkan bahwa kuat tekan untuk semua komposisi memenuhi batas minimum yang dipersyaratkan untuk stuktural ringan yaitu 6,89 MPa sesuai SNI 03-3449-2002. Demikian pula bobot jenis dari bata ringan yang dihasilkan masih dibawah dari batas maksimum yang direkomendasikan SNI 03-3449-2002 yaitu maksimal 1400 Kg/m3. Sedangkan daya serap air mengalami kenaikan dengan naiknya jumlah abu yang digunakan . Limbah padat abu boiler berbahan bakar cangkang dan serat sawit dapat dimanfaatkan sebagai bahan baku pembuatan bata beton ringan yang ramah lingkungan dengan memanfaatkan limbah dan menjadi salah satu alternatif pengelolaan limbah. Kata kunci :  Abu cangkang kelapa sawit,  bata beton ringan, bobot jenis,  daya serap air,  limbah,  kuat tekan


2021 ◽  
pp. 002199832110046
Author(s):  
Wei Feng ◽  
Chengwei Tang ◽  
Lei Liu ◽  
Jian Chen ◽  
Yang Zhang ◽  
...  

ZrB2 particles were preset to the C-AlSi interface to improve oxidation resistance of C/C preform and adjust the microstructure of the interpenetrated C/C-AlSi composite prepared through pressure infiltration of eutectic AlSi into a fiber fabric based porous C/C skeleton. Micro-morphology investigations suggested that the AlSi textures were changed from dendritic to petals-like state, and the nano to micro-scale ZrB2 particles were dispersed into AlSi and affected the distribution of Al and Si nearby carbon. Tests demonstrated that C/C-AlSi have slight lower density and thermal expansion coefficient, and higher original compressive strength, while C/C-ZrB2-AlSi composites presented an outstanding strength retention rate after thermal shock. Fracture and micro-morphology indicated that the influence of the preset ZrB2 to the interface of carbon and alloy greatly affected the generation and propagation of cracks, which determined the diverse compression behaviors of the composites before and after thermal shock.


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