scholarly journals Closed-Cell Powder Metallurgical Aluminium Foams Reinforced with 3 vol.% SiC and 3 vol.% Graphite

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 2031
Author(s):  
Jaroslav Kováčik ◽  
Martin Nosko ◽  
Natália Mináriková ◽  
František Simančík ◽  
Jaroslav Jerz
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Modulus Of Elasticity ◽  
Nominal Composition ◽  
Constant Density ◽  
Damping Properties ◽  
Compression Tests ◽  
Foaming Agent ◽  
Reinforcing Particles ◽  
Closed Cell

Closed-cell aluminium foams (nominal composition: AlSi12Mg0.6Fe0.3) were prepared by the powder metallurgical route (using 0.4 wt.% TiH2 untreated powder as the foaming agent). Pure foams and foams with the addition of 3 vol.% graphite or SiC powder were prepared. The microstructure and mechanical properties of the prepared aluminium foams containing reinforcing particles were investigated at constant density and compared to those of the pure foam. Vibration measurements were performed to determine the damping properties and modulus of elasticity of the foams. Uniaxial compression tests were performed to determine the following mechanical properties: collapse stress, efficiency of energy absorption, plateau length and densification strain of the foams. All the foams behaved in a brittle manner during compression. Finally, the effect of admixed graphite and SiC powders on the properties of the investigated foam was evaluated, discussed and modelled. The addition of powders changed all investigated properties of the foams. Only the efficiency of energy absorption at constant density was almost identical.

scholarly journals Static Mechanical Properties of Expanded Polypropylene Crushable Foam

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 249
Author(s):  
Przemysław Rumianek ◽  
Tomasz Dobosz ◽  
Radosław Nowak ◽  
Piotr Dziewit ◽  
Andrzej Aromiński
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Strain Rate ◽  
Energy Absorption ◽  
Experimental Tests ◽  
Absorption Capacity ◽  
Strain Rates ◽  
Foam Density ◽  
Energy Absorption Capacity ◽  
Closed Cell

Closed-cell expanded polypropylene (EPP) foam is commonly used in car bumpers for the purpose of absorbing energy impacts. Characterization of the foam’s mechanical properties at varying strain rates is essential for selecting the proper material used as a protective structure in dynamic loading application. The aim of the study was to investigate the influence of loading strain rate, material density, and microstructure on compressive strength and energy absorption capacity for closed-cell polymeric foams. We performed quasi-static compressive strength tests with strain rates in the range of 0.2 to 25 mm/s, using a hydraulically controlled material testing system (MTS) for different foam densities in the range 20 g/dm3 to 220 g/dm3. The above tests were carried out as numerical simulation using ABAQUS software. The verification of the properties was carried out on the basis of experimental tests and simulations performed using the finite element method. The method of modelling the structure of the tested sample has an impact on the stress values. Experimental tests were performed for various loads and at various initial temperatures of the tested sample. We found that increasing both the strain rate of loading and foam density raised the compressive strength and energy absorption capacity. Increasing the ambient and tested sample temperature caused a decrease in compressive strength and energy absorption capacity. For the same foam density, differences in foam microstructures were causing differences in strength and energy absorption capacity when testing at the same loading strain rate. To sum up, tuning the microstructure of foams could be used to acquire desired global materials properties. Precise material description extends the possibility of using EPP foams in various applications.

Correlation between Zirconium Addition and Compressive Properties of AZ31 Mg Alloy Foams

2011 ◽  
Vol 121-126 ◽  
pp. 75-79
Author(s):  
Bo Young Hur ◽  
Rui Zhao
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Mg Alloy ◽  
Compressive Properties ◽  
Absorption Properties ◽  
Compression Behavior ◽  
Foaming Agent ◽  
Az31 Mg Alloy ◽  
Absorption Characteristics ◽  
Zirconium Addition

The compressive behaviors of AZ31-Zr foams using Ca particles as thickening agent and CaCO3 powder as foaming agent were investigated in this study. The porosity was about 48.7%~72.9%, pore size was between 0.43~0.97 mm, and homogenous pore structures were obtained. Mechanical properties of AZ31 Mg alloy foams were investigated by means of UTM. The cellular AZ31 Mg foams possess superior comprehensive mechanical properties. The energy absorption characteristics and the effects of compression behavior on the energy absorption properties for the cellular AZ31 Mg foams have been investigated and discussed. The results show that with the addition of Zr, the Mg alloy foam has the highest energy absorption value of 16.26 MJ/m3 and the hardness value of 81.8 HV, which is much higher than that of the foams fabricated without Zr.

Controlling of Distribution of Mechanical Properties in Functionally-Graded Syntactic Foams for Impact Energy Absorption

2012 ◽  
Vol 706-709 ◽  
pp. 729-734 ◽  
Author(s):  
Masahiro Higuchi ◽  
Tadaharu Adachi ◽  
Yuto Yokochi ◽  
Kenta Fujimoto
Keyword(s):  
Mechanical Properties ◽  
Density Distribution ◽  
Energy Absorption ◽  
Impact Energy ◽  
Volume Fraction ◽  
Functionally Graded ◽  
Syntactic Foams ◽  
Compression Tests ◽  
Density Distributions ◽  
Control Distribution

In the study, novel fabrication processes of functionally-graded (FG) syntactic foams were developed to control distribution of the mechanical properties in the FG foams for highly impact energy absorption. In order to control mechanical properties, the density distributions in FG foams were graded by floating phenomenon of the light-weight micro-balloons in matrix resin during curing process. The density distribution in the foam could be controlled by adjusting the average volume fraction and the turning procedure of the mold before grading the micro-balloons in the foam. The compression tests of the fabricated FG foams suggested that the foams had high absorption of impact energy since the foams collapsed progressively due to the grading of the density distribution.

Methods for Filling Hollow Structures with Aluminium Foam

2010 ◽  
Vol 638-642 ◽  
pp. 61-66 ◽  
Author(s):  
Joachim Baumeister
Keyword(s):  
Energy Absorption ◽  
Hybrid Structure ◽  
Absorption Capacity ◽  
Aluminium Foam ◽  
Compression Tests ◽  
Foaming Agent ◽  
Hollow Structures ◽  
Industrial Sectors ◽  
Foam Filling ◽  
Application Potential

Aluminium foams produced according to the powder metallurgical/foaming agent process are currently being used in several industrial sectors, such as automotive, rail transport or machine tools. Nevertheless there still is a high further application potential to be exploited. Especially in hybrid structures, e.g. in automotive structures that are locally filled with aluminium foam, great improvements regarding the energy absorption capacity and the sound absorption behaviour can be obtained. In the present paper several methods that allow for filling or local filling of hollow structures are investigated and presented. The effect of the foam filling on the energy absorption behaviour of the hybrid structure is discussed. Similar effects were also observed in compression tests on foam filled hollow profiles. The results of these investigations are presented.

Effect of Blowing Agent and Polyethylene Glycol on Cellular Structure and Mechanical Properties of Chloroprene Rubber

2012 ◽  
Vol 217-219 ◽  
pp. 517-521 ◽  
Author(s):  
Hong Ling Yi ◽  
Ting Wei ◽  
Lin Heng ◽  
Bai Cun Zheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Zinc Oxide ◽  
Polyethylene Glycol ◽  
Cellular Structure ◽  
Foaming Agent ◽  
Blowing Agent ◽  
Swell Ratio ◽  
Closed Cell ◽  
Chloroprene Rubber

In this paper the closed-cell sponge of chloroprene rubber(CR) were produced by foaming agent Azodicarbonamide (AC) and Oxybis (benzene sulfonyl) hydrazide (OBSH). The blend blowing agent AC/OBSH was more effective than the pure AC as it could produce chloroprene foam with greater cell porosity, more uniform and better cell distributions. The CR foam prepared with AC/OBSH had better tensile strength and tear strength than pure AC, but higher Shore C hardness. The Polyethyene glycol (PEG) modified Zinc Oxide (ZnO) could accelerate curing and foam process simultaneously. Increase the content of PEG, CR foam has bigger swell ratio, smaller cell size, and better softness.

Experimental Determination of Mechanical Properties of Aluminium Foams Using Digital Image Correlation

2014 ◽  
Vol 601 ◽  
pp. 254-257 ◽  
Author(s):  
Tudor Voiconi ◽  
Emanoil Linul ◽  
Liviu Marsavina ◽  
Jaroslav Kováčik ◽  
Marcin Kneć
Keyword(s):  
Mechanical Properties ◽  
Digital Image Correlation ◽  
Yield Stress ◽  
Digital Image ◽  
Compressive Loading ◽  
Image Correlation ◽  
Compression Tests ◽  
Closed Cell

This paper presents an experimental characterization of three different types of closed-cell aluminium alloy foams (AlMg1Si0.6, AlSi12Mg0.6 and AlMg0.6Si0.3) under static compressive loading. This study was carried out on half-cylindrical specimens with skin. The influence of foam density on compressive behaviour was investigated for densities ranging from 430 kg/m3 to 935 kg/m3. The compression tests were performed at room temperature (23°C) with a constant crosshead speed of 0.5 mm/min. Strain distribution, yield stress and compressive modulus values were recorded using Digital Image Correlation. Experimental results show that the mechanical properties (Youngs Modulus, yield stress and plateau stress) increase with density.

scholarly journals 3D Printing of Thermoplastic Elastomers: Role of the Chemical Composition and Printing Parameters in the Production of Parts with Controlled Energy Absorption and Damping Capacity

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3551
Author(s):  
Marina León-Calero ◽  
Sara Catherine Reyburn Valés ◽  
Ángel Marcos-Fernández ◽  
Juan Rodríguez-Hernandez
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
3D Printing ◽  
Energy Absorption ◽  
Thermoplastic Elastomers ◽  
Damping Capacity ◽  
Compression Tests ◽  
Wide Range ◽  
Printing Parameters

Additive manufacturing (AM) is a disruptive technology that enables one to manufacture complex structures reducing both time and manufacturing cost. Among the materials commonly used for AM, thermoplastic elastomers (TPE) are of high interest due to their energy absorption capacity, energy efficiency, cushion factor or damping capacity. Previous investigations have exclusively focused on the optimization of the printing parameters of commercial TPE filaments and the structures to analyse the mechanical properties of the 3D printed parts. In the present paper, the chemical, thermal and mechanical properties for a wide range of commercial thermoplastic polyurethanes (TPU) filaments were investigated. For this purpose, TGA, DSC, 1H-NMR and filament tensile strength experiments were carried out in order to determine the materials characteristics. In addition, compression tests have been carried out to tailor the mechanical properties depending on the 3D printing parameters such as: infill density (10, 20, 50, 80 and 100%) and infill pattern (gyroid, honeycomb and grid). The compression tests were also employed to calculate the specific energy absorption (SEA) and specific damping capacity (SDC) of the materials in order to establish the role of the chemical composition and the geometrical characteristics (infill density and type of infill pattern) on the final properties of the printed part. As a result, optimal SEA and SDC performances were obtained for a honeycomb pattern at a 50% of infill density.

Mechanical Properties of E21 Ti3AlC-base Alloy

2006 ◽  
Vol 980 ◽  
Author(s):  
Hideki Hosoda ◽  
Tomonari Inamura ◽  
Kenji Wakashima
Keyword(s):  
Mechanical Properties ◽  
Base Alloy ◽  
The Body ◽  
Nominal Composition ◽  
Second Phase ◽  
Positive Temperature ◽  
Compression Tests ◽  
Octahedral Interstitial Site ◽  
Temperature Range ◽  
Average Grain Size

AbstractMechanical properties and phase constitution of an E21-type Ti3AlC-base alloy were investigated by compression tests in a temperature range from room temperature (RT) to 1273K, scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The unit cell of E21 Ti3AlC is constructed by ¡§L12 Ti3Al¡¨ and a carbon atom occupying the body-center octahedral-interstitial-site surrounded by the Ti atoms. The nominal composition of the alloy was chosen to be the stoichiometric composition of 60mol%Ti-20mol%Al-20mol%C. The alloy was synthesized by mechanical alloying using high purity elemental powders followed by hot pressing at 1473K for 3hrs. It was found by XRD and SEM that the alloy was mainly composed of E21 Ti3AlC in addition to Cr2AlC-type Ti2AlC precipitates as a second phase. The density of Ti3AlC is calculated to be 4.29g/cm3 based on the lattice parameter of 0.4134nm of E21. The average grain size was 2μm by SEM. By the compression tests, the 0.2% flow stress at the temperature range from RT to 1073K exceeded 1GPa. The yield stress is comparably higher than those of other E21 intermetallic carbides: at 1073K, 1084MPa for Ti3AlC, 50MPa for Mn3AlC and 135MPa for Fe3AlC. Besides, a weak positive temperature dependence of strength was observed where the peak temperature was around 900K. This suggests that a Kear-Wilsdorf type dislocation pinning mechanism may be activated. It is concluded that E21 Ti3AlC-base alloy shows promise for a new high-temperature light-weight structural material.

On the Damping Properties of a Polyurea Elastomer

2014 ◽  
Vol 887-888 ◽  
pp. 21-25 ◽  
Author(s):  
Fabrizia Ghezzo ◽  
Xi Geng Miao ◽  
Chun Lin Ji ◽  
Ruo Peng Liu
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Energy Absorption ◽  
Mechanical Characterization ◽  
Environmental Engineering ◽  
Damping Properties ◽  
Structural Vibrations ◽  
Bulk Materials ◽  
Absorption Properties ◽  
Impact Events

The development of materials with high damping and energy absorption properties in the form of bulk materials or coatings is today a target for designing components and structures with improved durability and survivability to serve in fields such as aeronautical, mechanical, civil and environmental engineering. This paper presents the results of the dynamic mechanical characterization conducted on reinforced polyurea composites. The mechanical properties of two types of composite materials utilizing the polyurea elastomer as a matrix are compared with those of the pure polymer. The composite materials show a substantial increase of the damping ability. Such materials can be produced in the form of coatings and successfully applied for maximizing the damping of mechanical and structural vibrations or for limiting the damage effects of impact events on structures and components.

Preparation and Properties of Closed Cell Aluminum–Fly Ash Floating Beads Composite Foam

2012 ◽  
Vol 217-219 ◽  
pp. 59-62
Author(s):  
Hong Feng Luo ◽  
Shao Jie Weng ◽  
Yue Li ◽  
Zhi Shui Chen ◽  
Mao Lin
Keyword(s):  
Fly Ash ◽  
Strain Curve ◽  
Processing Parameters ◽  
Compression Tests ◽  
Static Compression ◽  
Composite Foam ◽  
Foaming Agent ◽  
Closed Cell ◽  
Compression Region ◽  
Foaming Temperature

Closed cell aluminum–fly ash floating beads composite foam was fabricated by stirring casting method. The reasonable processing parameters are: the foaming temperature is 750°C, the amount of foaming agent is 2%, and the foaming time is 8 min. Quasi-static compression tests shows that stress and strain curve of closed cell aluminum–fly ash floating beads composite foam have three regions, i.e. the elastic region, the stress platform region and the compression region.

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