Effect of Foaming Temperature on Pore Morphology of Al/AlN Composite Foam Fabricated by Melt Foaming Method

2010 ◽  
Vol 658 ◽  
pp. 189-192 ◽  
Author(s):  
Yeong Hwan Song ◽  
Masakazu Tane ◽  
Takuya Ide ◽  
Yoshihiro Seimiya ◽  
Bo Young Hur ◽  
...  
Keyword(s):  
Nitrogen Atmosphere ◽  
Al Alloy ◽  
Pore Morphology ◽  
Composite Foam ◽  
Blowing Agents ◽  
Composite Foams ◽  
Foaming Behavior ◽  
Foaming Temperature ◽  
Powder Compacts ◽  
Al Foams

Al foams whose matrix contains dispersed AlN particles (Al/AlN composite foams) were prepared by a melt foaming method, and the effect of foaming temperature on the pore morphology of the prepared foams was investigated. First, Al/AlN composites were prepared by non-compressive infiltration of Al powder compacts with molten Al alloy in nitrogen atmosphere. Next, the prepared composites were melted by induction heating and foamed at various temperatures using TiH2 powders as blowing agents. The porosity of prepared Al/AlN composite foams slightly decreases with increasing foaming temperature, and the pore morphology of the foam becomes homogeneous simultaneously. When the foaming temperature is 1123 K, homogeneous pores are formed in all over the ingot. This pore homogeneity is probably achieved by the stabilization of the foaming behavior due to the formation of Al3Ti particles in the melt and dispersion of AlN particles.

The Influence of Amount of Wood Fiber on New Flame-Retardant Melamine-Urea-Formaldehyde (MUF) Composite Foam

2011 ◽  
Vol 393-395 ◽  
pp. 1012-1017 ◽  
Author(s):  
Yu Feng Ma ◽  
Wei Zhang ◽  
Ling Li ◽  
Ming Ming Zhang ◽  
Zeng Hui Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Cell Shape ◽  
Urea Formaldehyde ◽  
Wood Fiber ◽  
Cell Size Distribution ◽  
Composite Foam ◽  
Composite Foams ◽  
Flame Retardant Properties ◽  
Irregular Cell

New composite foams were prepared by co-foaming of Melamine-Urea-Formaldehyde (MUF) resin and wood fiber in the closed mould at 70°C. The effects of amount of wood fiber on mechanical properties, brittleness, flame-retardant, insulation and microscopic structures of wood fiber-MUF foam were investigated. Results indicated that the flame-retardant properties increased, and the brittleness and mechanical properties decreased with the increase of the amount of wood fiber in composite foams. The addition of wood fiber resulted in more uniform cell size distribution and irregular cell shape, but had little effect on insulation properties.

scholarly journals Study on Flame Retardancy and Mechanism of Talc Composite Foams

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiujuan Li ◽  
Ruisong Guo ◽  
Xiaodong Qian
Keyword(s):  
High Temperature ◽  
Fire Resistance ◽  
Flame Retardancy ◽  
Dense Layer ◽  
Composite Foam ◽  
Fire Extinguishing ◽  
Fuel Burning ◽  
Composite Foams ◽  
Film Forming ◽  
Improved Stability

Under high temperature, aqueous film forming foam extinguishing agent has poor flame retardancy and low fire efficiency. In order to solve this problem, talc was introduced into foam to form composite foam. The fire resistance and fire extinguishing properties of the composite foam were studied. The results showed that talc composite foam had good flame retardant resistance. when the concentration of talc reached 40 g/100 ml, the 50% liquid separation time of the composite foam was 21.1 min. The fuel burning in the anti burning tank did not ignite the gasoline in the oil pan, and burned out at 51.5 min. It was related to the structure of composite foam and the properties of talc. Due to the introduction of talc, the viscosity of the composite foam increased. The network structure of composite foam was important to the improved stability of foam. Talc powder formed a dense layer covering the oil surface, which effectively isolated the oil from the air.

Tensile Properties of Natural Fibre Reinforced Polymer Composite Foams: A Systematic Review

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
NurFadhlin Sakina Jamil ◽  
◽  
Mazatusziha Ahmad ◽  
Ahmad Hakiim Jamaluddin ◽  
◽  
...  
Keyword(s):  
Systematic Review ◽  
Tensile Properties ◽  
Polymer Composite ◽  
Natural Fibre ◽  
Fibre Content ◽  
Composite Foam ◽  
Fibre Size ◽  
Reinforced Polymer ◽  
Composite Foams ◽  
Fibre Reinforced Polymer

Biodegradable foam packaging was chosen as an alternative food packaging material due to non-toxic and produced from renewable sources. Researchers has turned to incorporate natural fibre to enhance the mechanical properties of polymer composite foam. In this study, the objective is to identify the studies which investigated on the tensile properties of natural fiber incorporated polymer composite foam and analyzed the effect of natural fibre content and size on tensile properties. Further correlation between the natural fibre content and size on tensile properties of composite polymer foam was conducted. The studies on the natural fibre incorporated polymer composite was identify via PRISMA method. The effect of natural fibre content and natural fibre size on tensile properties of polymer composite foam were analyzed in terms of qualitative analysis via systematic review. This study employs systematic review method on the existing literature. This study has utilized supplementary databases such as SAGE Journals, ScienceDirect, Taylor & Francis, Emerald Insight, ERIC ProQuest, SpringerLink and IEEE Xplore to cater all the possible relevant literature for a comprehensive review. The systematic review method comprised of the steps that explain on the review process in the sequence of the (identification, screening, eligibility), data analysis and data abstraction. From the article used in this systematic review, most of the result shown the increased tensile properties on natural fibre reinforced polymer composite foams. The study by Texteira et al. (2014) shows that the softwood fibre with 33% of PLA loading has the highest elongation at break, and highest natural fibre size (2470 µm). While the study by Long et al. (2019) has the highest tensile strength with 30% of ABF fibre content. The composition of 20 wt% BF with 80 wt% PLA composites were concluded to have the optimum tensile properties

scholarly journals The Fabrication of Geopolymer Foam Composites Incorporating Coke Dust Waste

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1052
Author(s):  
Buczkowska Katarzyna ◽  
Chi Hiep Le ◽  
Petr Louda ◽  
Szczypiński Michał ◽  
Totka Bakalova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
Composite Foam ◽  
Coke Dust ◽  
Composite Foams ◽  
Negative Effect ◽  
Geopolymer Binder

This paper reports the results of an experimental investigation on the mechanical properties of geopolymer foams incorporating filler from the coke dust waste (CDW). In this work, CDW was used to replace a part of geopolymer paste at 5%, 10%, 20%, and 30% by geopolymer binder mass. The physico-mechanical properties and thermal resistance against high temperatures of CDW/geopolymer foams are presented. The primary results obtained show that the use of CDW in the production of geopolymer foam composites made it possible for them to achieve relatively good mechanical properties. However, the incorporation of the CDW into the geopolymer had a slightly negative effect on thermal conductivity, but significantly improved the mechanical strength of the final product. Moreover, this waste also helped the composite foam to achieve a structure with more uniform open pores distribution, compared to the pure foam. After exposure to elevated temperatures, the residual strength of the composite foams maintained well compared to the pure foams.

Preparation and properties of polyimide/Fe3O4 composite foams

2018 ◽  
Vol 47 (2) ◽  
pp. 173-179 ◽  
Author(s):  
Ling Weng ◽  
Ting Wang ◽  
Pei-Hai Ju ◽  
Li-Zhu Liu
Keyword(s):  
Electromagnetic Interference ◽  
Temperature Stability ◽  
Electromagnetic Shielding ◽  
Great Promise ◽  
Electromagnetic Interference Shielding ◽  
High Temperature Stability ◽  
Composite Foam ◽  
Content Type ◽  
Nanocomposite Foams ◽  
Composite Foams

Purpose This paper aims to develope the electromagnetic interference shielding materials with high performance. To develop advanced polymer-based electromagnetic interference shielding materials with rather high temperature stability, good processability and moderate mechanical properties, the authors chose the polyimide (PI) foam as matrix and ferriferrous oxide (Fe3O4) as fillers to prepare the composite foams with lightweight and rather good electromagnetic interference shielding performance. Design/methodology/approach Some polyimide nanocomposite foams with Fe3O4 as fillers have been prepared by in situ dispersion and foaming with pyromellitic dianhydride (PMDA) and isocyanate (PAPI) as raw materials and water as foaming agent. By varying the Fe3O4 contents, a series of PI/Fe3O4 nanocomposite foams with fine microstructures and high thermal stability were obtained. The structure and performances of nanocomposite foams were examined, and the effects of Fe3O4 on the microstructure and properties of composite foams were investigated. Findings This work demonstrates that PI/Fe3O4 foams could be fabricated by thermally treating the polyimide foam intermediates with Fe3O4 nanoparticles through a blending reaction of precursors. The final PI/Fe3O4 composite foams maintained the excellent thermal property and showed a super paramagnetic behaviour, which has a positive effect on the improvement of electromagnetic shielding performance. Research limitations/implications In this paper, the effects of Fe3O4 on the performances of PI/Fe3O4 composite foam were reported. It provided an effective methodology for the preparation of polymer/Fe3O4 nanocomposite foams, which hold great promise towards the potential application in the areas of electromagnetic shielding materials. Originality/value A series of PI/Fe3O4 composite foams with different contents of Fe3O4 were prepared by blending reaction of the precursors. The effects of Fe3O4 on the structures and properties of PI/Fe3O4 composite foam were discussed in detail.

Formability of Open-Cell Aluminum Foams by Laser

2010 ◽  
Author(s):  
Loredana Santo ◽  
Alessandro Guglielmotti ◽  
Fabrizio Quadrini
Keyword(s):  
Element Model ◽  
Laser Forming ◽  
Process Conditions ◽  
Al Alloy ◽  
Aluminum Foams ◽  
Bending Tests ◽  
Open Cell ◽  
Laser Velocity ◽  
Material Interaction ◽  
Al Foams

A new forming method for open-cell aluminum (Al) foams by laser was introduced. Laser forming is generally applied to sheet metals but a good formability was observed also for Al alloy cellular structures. In this study, laser bending tests were performed on rectangular samples made of open-cell Al alloy foams by means of a diode laser. Laser scan velocity and power were changed in the experimentation so as to identify the best process conditions for three different Al foams. A finite element model was implemented to simulate the laser-material interaction during forming in dependence of the foam structure. At fixed values of laser velocity and power, higher bending angles were obtained for foams with smaller pores but, changing the process parameters, a better formability was observed for the foams with bigger pores.

Flame Retardant Effect of a Modified Intumescent Flame Retardant on a Rigid Polyurethane Foam

2017 ◽  
Vol 748 ◽  
pp. 51-54
Author(s):  
Pei Bang Dai ◽  
Lin Ying Yang ◽  
Ting Zheng ◽  
Chang Qin ◽  
Qi Chen Tang
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Intumescent Flame Retardant ◽  
Limiting Oxygen Index ◽  
Composite Foam ◽  
Composite Foams ◽  
Suitable Amount ◽  
Ul 94 ◽  
Pu Foams

A rigid polyurethane (PU) flame retardant composite foam was prepared by the compounding of polyols and diisocyanates with a modified intumescent flame retardant (MIFR). The MIFR was based on the three components of intumescent flame retardant normally used and was modified in a surfactant TX-10 solution. The flame retardancy of the PU flame retardant composite foams were evaluated by using the limiting oxygen index (LOI), the UL-94 (vertical flame) test and scanning electron microscopy (SEM). When MIFR was fixed at 20.0 wt% in PU/MIFR composite foams, the MIFR could enhance the flame retardancy and pass V-0 rating of UL-94 test. The microstructures observed by SEM demonstrate that a suitable amount of MIFR can promote formation of compact intumescent charred layers in PU foams.

scholarly journals Al-Based Foams as Permanent Cores in Al Castings: Effect of Surface Skin Thickness and Composition on Infiltration and Core-Shell Bonding

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1715
Author(s):  
Sara Ferraris ◽  
Antonio Santostefano ◽  
Antonio Barbato ◽  
Roberto Molina ◽  
Graziano Ubertalli
Keyword(s):  
Skin Thickness ◽  
Al Alloy ◽  
Strength Increase ◽  
Aluminum Foams ◽  
Gravity Casting ◽  
Acoustic Insulation ◽  
Metallurgical Bonding ◽  
Compression Resistance ◽  
Effect Of Surface ◽  
Al Foams

An emerging and still poorly explored application of aluminum foams is their potential use as permanent cores (inserts) in the casting of aluminum alloys. In this context, Al-based foams can introduce a weight reduction, the obtainment of cavities, a strength increase, the ability to absorb impact energy and vibration, acoustic insulation ability, the possibility to simplify the technological processes (no removal/recycling of traditional sand cores), and finally, they can be fully recyclable. Cymat-type Al foams with thin outer skin were used as permanent cores in Al-alloy gravity casting in the present research. Al-foams were characterized in terms of porosity, density, cell wall and skin thickness, surface chemical composition and morphology, and compression resistance. Cast objects with foam inserts were characterized by means of optical microscopy. The preservation of up to 50% of the initial porosity was observed for foam inserts with higher density. Metallurgical bonding between the foam core and the cast metal was observed in some regions.

Modelling the Strength of Cellulose Nanofiber-Filled Rigid Low-Density PU Foams

2019 ◽  
Vol 827 ◽  
pp. 159-164 ◽  
Author(s):  
Janis Andersons ◽  
Mikelis Kirpluks ◽  
Ugis Cabulis
Keyword(s):  
Cellulose Nanofibers ◽  
Low Density ◽  
Insulation Material ◽  
Composite Foam ◽  
Foaming Process ◽  
Composite Foams ◽  
Closed Cell ◽  
Strength And Stiffness ◽  
Sufficient Strength ◽  
Pu Foams

Rigid low-density closed-cell polyurethane (PU) foams are used primarily as a thermal insulation material. The foams have to possess a sufficient strength and stiffness in order to ensure their mechanical integrity and dimensional stability in service. The mechanical characteristics of foams are enhanced by adding cellulose nanofibers to the polyol system, which both modify the foaming process and act as a reinforcement of cell struts and walls. A model of composite foam strength is developed based on a regular unit cell and assuming the onset of strut failure as the foam fracture criterion. The load-bearing capacity of foam struts is estimated by the modified Fukuda and Chou model considering the orientation of nanofibers along the strut axis. The model developed is shown to provide a reasonably accurate prediction for the nanofiber loading effect on the strength of composite foams.

Sign in / Sign up

Export Citation Format

Share Document