Study on Fabrication, Defects and Compression Properties of Al Foams at Different Foaming Temperatures

2011 ◽  
Vol 214 ◽  
pp. 70-74 ◽  
Author(s):  
Wei Min Zhao ◽  
Hui Zhang ◽  
Hai Peng Li ◽  
Zhi Feng Wang ◽  
Yang Zhao ◽  
...  
Keyword(s):  
Pore Structure ◽  
Aluminum Foams ◽  
Foaming Agent ◽  
Compression Properties ◽  
Al Powder ◽  
Fabrication Defects ◽  
Lower Temperature ◽  
Foaming Temperature ◽  
Better Than ◽  
Al Foams

Using Al powder as thickening agent and CaCO3 powder as foaming agent, Al foams with above 85% porosity, pore sizes between 1mm and 4mm and relatively uniform pore structure have been fabricated by melt foaming method at different foaming temperatures. Meanwhile, the paper researched the effect of foaming temperature on foaming effect and analyzed the defects in Al foams. At last, compression test were taken in order to investigate the mechanical properties of aluminum foams. The results showed that pore structure, pore distribution and compression properties of Al foams fabricated at 720°C were much better than that fabricated at lower temperature.

scholarly journals The correction of foam glass composition based on its principal parameters

2021 ◽  
Vol 350 ◽  
pp. 00009
Author(s):  
Dmitry Safonchik ◽  
Svetlana Maksimovich
Keyword(s):  
Mechanical Characteristics ◽  
Glass Composition ◽  
Foam Glass ◽  
Cost Price ◽  
Foaming Agent ◽  
Insulating Material ◽  
Leading Position ◽  
The Cost ◽  
Foaming Temperature ◽  
Better Than

Thermal insulation materials are the main link in solving the problem of enclosing constructions energy efficiency. The number of heat insulators is relatively low, that`s why it is important to develop new insulators that would be better than the existing ones in their characteristics. Such heat-insulating material as foam glass is known, but it is practically not applied, despite the fact that it possesses high heatinsulating and mechanical characteristics, it is non-combustible, durable and environmentally friendly. All the advantages of foam glass are inferior to one drawback. It is the high cost price of this material. If the cost price of foam glass was reduced and its main characteristics were at the same level, foam glass would take a leading position among other heatinsulating materials. The article presents some information about the development of foam glass, in which dolomite flour is used as a foaming agent. The material proposed by the authors has a density of about 200 kg / m3, water absorption of 25%. The material is manufactured at maximum foaming temperature of 750 °C.

scholarly journals Effects of Porosity and Pore Structure on Compression Properties of Blowing-Agent-Free Aluminum Foams Fabricated from Aluminum Alloy Die Castings

2012 ◽  
Vol 53 (8) ◽  
pp. 1515-1520 ◽  
Author(s):  
Yoshihiko Hangai ◽  
Hiroki Kato ◽  
Takao Utsunomiya ◽  
Soichiro Kitahara ◽  
Osamu Kuwazuru ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Pore Structure ◽  
Aluminum Foams ◽  
Blowing Agent ◽  
Compression Properties ◽  
Die Castings

scholarly journals Enhancing Density-Based Mining Waste Alkali-Activated Foamed Materials Incorporating Expanded Cork

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 523-540
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
Porous Structures ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

This study focuses on the development of an alkali-activated lightweight foamed material (AA-LFM) with enhanced density. Several mixes of tungsten waste mud (TWM), grounded waste glass (WG), and metakaolin (MK) were produced. Al powder as a foaming agent was added, varying from 0.009 w.% to 0.05 w.% of precursor weight. Expanded granulated cork (EGC) particles were incorporated (10% to 40% of the total volume of precursors). The physical and mechanical properties of the foamed materials obtained, the effects of the amount of the foaming agent and the percentage of cork particles added varying from 10 vol.% to 40% are presented and discussed. Highly porous structures were obtained, Pore size and cork particles distribution are critical parameters in determining the density and strength of the foams. The compressive strength results with different densities of AA-LFM obtained by modifying the foaming agent and cork particles are also presented and discussed. Mechanical properties of the cured structure are adequate for lightweight prefabricated building elements and components.

FOAMING AGENT FOR ALLOYS OF ALUMINIUM FOAMS

2018 ◽  
Vol 32 (2) ◽  
pp. 53-59
Author(s):  
Jozsef Juhasz ◽  
Vasile Hotea ◽  
Keyword(s):  
Thermal Analysis ◽  
Pore Structure ◽  
Powder Compact ◽  
Matrix Alloy ◽  
Aluminium Foam ◽  
Foaming Agent ◽  
Melting Technique ◽  
Foam Production

The powder compact melting technique for aluminium foam production as practised today accepts a certain mismatch between foaming agent decomposition and matrix alloy melting temperatures.This mismatch is believed to influence the pore structure in an unfavourable way. Adjustment of TiH 2 decomposition as well as liquidus and solidus temperatures of matrix alloys can be used to counteract it. Effects of TiH 2 thermal are investigated using thermal analysis. TiH 2 variants gained via annealing treatments were used to produce aluminium foam precursor materials.

scholarly journals Effect of the Operational Conditions in the Characteristics of Ceramic Foams Obtained from Quartz and Sodium Silicate

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1806
Author(s):  
Lina Uribe ◽  
Juan D. Giraldo ◽  
Alejandro Vargas
Keyword(s):  
Pressing Pressure ◽  
Melting Points ◽  
Statistical Software ◽  
Powder Mixtures ◽  
Foaming Agent ◽  
Ceramic Foams ◽  
Cellular Solid ◽  
Operational Conditions ◽  
Volumetric Expansion ◽  
Foaming Temperature

Ceramic foams were fabricated without using melting pots through the direct foaming of compacted powder mixtures of commercial quartz (SiO2) with fluxing agents (Na2CO3 and CaO) and a foaming agent (Na2SiO3·5H2O) at a relatively low temperature range (850−870 °C). The effects of the pressing pressure of the powders, the foaming time, foaming temperature, and mixture content were evaluated. The obtained cellular solid materials presented an acceptable volumetric expansion at a pressing pressure of 4 t. The materials only presented porosity at a minimum temperature of 850 °C and at a minimum time of 30 min. All the foamed samples showed an acceptable symmetric expansion and non-appreciable fissures. The study of the mixture content through the statistical software MODDE® shows that the porosity of the samples was principally affected by the Na2SiO3 content and the foaming temperature. The samples obtained at the optimum controlling factors proposed by this statistical software presented an apparent density, porosity, and mechanical strength of 1.09 ± 0.03 g/cm3, 56.01% ± 1.12%, and 3.90 ± 0.16 MPa, respectively. Glass and ceramics foams such as those obtained in this work become attractive as insulation materials in applications where high temperatures occur due to their higher melting points.

scholarly journals Effect of Phenolic Particles on Mechanical and Thermal Conductivity of Foamed Sulphoaluminate Cement-Based Materials

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3596 ◽  
Author(s):  
Xiuzhi Zhang ◽  
Qing Yang ◽  
Qinfei Li ◽  
Heng Chen ◽  
Guofa Zheng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Pore Structure ◽  
Dry Density ◽  
Mechanical And Thermal Properties ◽  
Foaming Agent ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Performance Indexes ◽  
Foamed Concrete ◽  
Inorganic Matrix

Foamed concrete materials based on sulpoaluminate cement were prepared by the chemical foaming method. The effects of water–cement ratio, foaming agent, and foaming stabilizer on the mechanical and thermal properties of foamed concrete were studied. Meanwhile, a portion of cement was replaced with foamed phenolic particles to further optimize the performance of foamed concrete; the results show that when the water–cement ratio was 0.53, the foaming agent content was 5%, the foam stabilizer was 1%, and the substitution of phenolic particles was 20%, the performance indexes of foamed concrete were the best. Methods, describing briefly the main methods or treatments applied: dry density was 278.4 kg/m3, water absorption was 19.9%, compressive strength was 3.01 MPa, and thermal conductivity was 0.072 W/(m·K). By the pore structure analysis of the foamed concrete suing Micro-CT, it was found that when the replacement amount of phenolic particles was 20%, the pore size of foamed concrete was relatively uniform, the minimum D90 was 225 μm respectively. The combination of organic and inorganic matrix and optimized pore structure improved the performance of foamed concrete.

Preparation of Foam Glass Ceramics from Phosphorus Slag

2010 ◽  
Vol 105-106 ◽  
pp. 600-603 ◽  
Author(s):  
Ben Xu ◽  
Kai Ming Liang ◽  
J.W. Cao ◽  
Y.H. Li
Keyword(s):  
Glass Powder ◽  
Foam Glass ◽  
Glass Ceramics ◽  
Processing Parameters ◽  
Treatment Temperature ◽  
Homogeneous Distribution ◽  
Sintering Process ◽  
Foaming Agent ◽  
Foaming Temperature ◽  
Foam Glass Ceramics

Phosphorus slag could be used to prepare wollastonite glass ceramics. With the aid of incorporated foaming agent, foam glass ceramics can be obtained via the sintering of the slag-based glass. After the glass powder reacted with graphite, macro-size pores with homogeneous distribution were formed. The level of porosity of the fabricated foams was controlled by varying heat treatment temperature and amount of foaming agent. It was found that the preferential processing parameters for producing foam glass ceramics were foaming temperature of 1000°C with holding time of 10 min and 1 wt. % of graphite. In this case, the porosity reached about 80%. The results show that dominant crystalline phase is wollastonite, and the high compression strength results from the crystallization of glass during sintering process.

Porous Material Production and Material Properties

2019 ◽  
Vol 946 ◽  
pp. 84-90
Author(s):  
Liudmila Shtirc ◽  
Svetlana G. Vlasova ◽  
Dmitry Meshcherskikh
Keyword(s):  
Porous Material ◽  
Caustic Soda ◽  
Material Properties ◽  
Foaming Agent ◽  
Experimental Glass ◽  
Material Production ◽  
Foaming Process ◽  
Foaming Temperature ◽  
Glass Compositions

In our work we defined two directions for synthesizing porous material: pulping selected experimental glass compositions and using caustic soda as a foaming agent. We studied the foaming temperature settings, investigated the porous material properties. The intensity of the foaming process was estimated from the value of the foaming coefficient.

scholarly journals Expansion volume of alkali activated foamed cork composites from tungsten mining mud waste with aluminium

2019 ◽  
Vol 274 ◽  
pp. 03002
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes ◽  
Haroon Ihsan ◽  
John Pickstone ◽  
Nuno Estrada
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical And Mechanical Properties ◽  
Mechanical And Thermal Properties ◽  
Porous Structures ◽  
Expansion Process ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

Several mixes of alkali activated foams from tungsten mud waste (MW), grounded glass (GG) and metakaolin (MK) were developed incorporating expanded granulated cork (EGC). This study presents preliminary results of the expansion process obtained with the addition of aluminium (AL) powder as a foaming agent. 0.3 wt.%, 0.4 wt.% to 0.5wt.% of AL powder were added to the alkali activated matrix. The physical and mechanical properties of the obtained foams, the effects of the type and amount of the foaming agent added are presented and discussed. Highly porous structures were obtained, with overall expansion up to 68.2% when the AL powder was added. The size and distribution of pores are shown. The compressive strength of foams in the case of highly porous structures achieved of 1.2 MPa for the samples containing 0.5 wt.% of AL powder. Mechanical and thermal properties of the cured structure are good and can therefore be used for applications in acoustic panels and lightweight prefabricated components for thermal insulation purposes.

Desiccation survival of larval and abult stages of the plant parasitic nematodes, Ditylenchus dipsaci and D. myceliophagus

Parasitology ◽  
1977 ◽  
Vol 74 (2) ◽  
pp. 139-148 ◽  
Author(s):  
R. N. Perry
Keyword(s):  
Stage Larva ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
General Survival ◽  
Ditylenchus Dipsaci ◽  
Lower Temperature ◽  
Plant Parasitic ◽  
Better Than

The effect of different relative humidities on the survival of individual larvae and adults of Ditylenchus dispasci and D. myceliophagus has been examined; experiments were carried out at 5 and 18°C with D. myceliophagusand at 18°C with D. dipsaci. Survival of both species was enhanced when they were dried at high humidities and, for D. myceliophagus, by the lower temperature. The survival of all stages of D. myceliophagus was poor. Generally it was expressed in minutes only; 4th-and 3rd-stage larvae, however, were marginally better at surviving drying than adults and much better than 2nd-stage larvae.Although the 4th-stage larva of D. dipsaci was overwhelmingly superior to all other stages, the 3rd stage, and to a lesser extent, the adult of this species also showed remarkable powers of survival to desiccation. In general, survival of 4th-, 3rd- and 2nd-stage larvae could be expressed in weeks, days and minutes respectively; for adults, survival was expressed in hours at relative humidites under 50% but in days at higher relative humidites.The results are discussed in relation to the survival value of the aggregations formed by these species; the validity of the term ‘resistantstage’ as applied to the 4th-stage larva of D. dipsaci is assessed.

Sign in / Sign up

Export Citation Format

Share Document