Initial yield behaviour of closed-cell aluminium foams in biaxial loading

2021 ◽  
Vol 191 ◽  
pp. 106063
Author(s):  
Balaji Vengatachalam ◽  
Rong Huang ◽  
Leong Hien Poh ◽  
Zishun Liu ◽  
Qinghua Qin ◽  
...  
Keyword(s):  
Biaxial Loading ◽  
Initial Yield ◽  
Closed Cell ◽  
Yield Behaviour

Numerical Analysis of Elastoplastic Behavior of Foams with Ellipsoidal Pores

2011 ◽  
Vol 462-463 ◽  
pp. 301-306 ◽  
Author(s):  
Zhi Min Xu ◽  
Wei Xu Zhang ◽  
Tie Jun Wang
Keyword(s):  
Yield Stress ◽  
Gas Pressure ◽  
Uniaxial Tensile ◽  
Face Centered Cubic ◽  
The Finite Element Method ◽  
Elastoplastic Behavior ◽  
Initial Yield Stress ◽  
Initial Yield ◽  
Closed Cell ◽  
Face Centered

The objective of this work is to numerically investigate the elastoplastic behavior of closed-cell foams. Anisotropic geometry with ellipsoidal pores is considered and the contribution of the inner gas pressure within the cells is incorporated to the model. Based on face centered cubic (FCC) arrangements of pores and the finite element method, macroscopic elastic constants and initial yield stress against the relative density and cell aspect ratio are discussed in this paper. Through a systematic study we find that the initial yield stress is dependent on the loading direction. The inner gas pressure results in the asymmetry of uniaxial tensile-compressive stress-strain curves and significantly affects the initial yield stress of the foams for different loading directions.

Electron energy loss near edge structures of intermetallic alloys and grain boundaries in NiAl

1996 ◽  
Vol 54 ◽  
pp. 522-523
Author(s):  
G.A. Botton ◽  
C.J. Humphreys
Keyword(s):  
High Temperature ◽  
Transition Metal ◽  
Energy Loss ◽  
Grain Boundaries ◽  
Industrial Applications ◽  
Edge Structure ◽  
Structural Applications ◽  
Yield Behaviour ◽  
Late Transition ◽  
Metal Aluminides

Transition metal aluminides are of great potential interest for high temperature structural applications. Although these materials exhibit good mechanical properties at high temperature, their use in industrial applications is often limited by their intrinsic room temperature brittleness. Whilst this particular yield behaviour is directly related to the defect structure, the properties of the defects (in particular the mobility of dislocations and the slip system on which these dislocations move) are ultimately determined by the electronic structure and bonding in these materials. The lack of ductility has been attributed, at least in part, to the mixed bonding character (metallic and covalent) as inferred from ab-initio calculations. In this work, we analyse energy loss spectra and discuss the features of the near edge structure in terms of the relevant electronic states in order to compare the predictions on bonding directly with spectroscopic experiments. In this process, we compare spectra of late transition metal (TM) to early TM aluminides (FeAl and TiAl) to assess whether differences in bonding can also be detected. This information is then discussed in terms of bonding changes at grain boundaries in NiAl.

Effect of cell size on the energy absorption of closed-cell aluminum foam

2018 ◽  
Vol 60 (6) ◽  
pp. 583-590 ◽  
Author(s):  
Jinglin Xu ◽  
Jianqing Liu ◽  
Wenbin Gu ◽  
Zhenxiong Wang ◽  
Xin Liu ◽  
...  
Keyword(s):  
Cell Size ◽  
Energy Absorption ◽  
Aluminum Foam ◽  
Closed Cell

Innovative Closed-Cell Reactor Permits In Situ Heating and Gas Reactions with Atomic Resolution at Atmospheric Pressure

2012 ◽  
Vol 18 (S2) ◽  
pp. 1118-1119 ◽  
Author(s):  
L. Allard ◽  
S.H. Overbury ◽  
M.B. Katz ◽  
W.C. Bigelow ◽  
D. Nackashi ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Atomic Resolution ◽  
Closed Cell ◽  
Cell Reactor ◽  
In Situ Heating ◽  
Gas Reactions

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

On multiaxial failure behavior of closed-cell aluminum foams under medium strain rates

2021 ◽  
Vol 160 ◽  
pp. 107278
Author(s):  
Erdong Wang ◽  
Guangyong Sun ◽  
Gang Zheng ◽  
Qing Li
Keyword(s):  
Failure Behavior ◽  
Strain Rates ◽  
Aluminum Foams ◽  
Closed Cell

scholarly journals Polyurethane Composite Foams Synthesized Using Bio-Polyols and Cellulose Filler

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3474
Author(s):  
Katarzyna Uram ◽  
Milena Leszczyńska ◽  
Aleksander Prociak ◽  
Anna Czajka ◽  
Michał Gloc ◽  
...  
Keyword(s):  
Cross Sections ◽  
Raw Materials ◽  
Polyurethane Foams ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Polyurethane Composite ◽  
Composite Foams ◽  
Closed Cell ◽  
Ft Ir ◽  
The Fourier Transform

Rigid polyurethane foams were obtained using two types of renewable raw materials: bio-polyols and a cellulose filler (ARBOCEL® P 4000 X, JRS Rettenmaier, Rosenberg, Germany). A polyurethane system containing 40 wt.% of rapeseed oil-based polyols was modified with the cellulose filler in amounts of 1, 2, and 3 php (per hundred polyols). The cellulose was incorporated into the polyol premix as filler dispersion in a petrochemical polyol made using calenders. The cellulose filler was examined in terms of the degree of crystallinity using the powder X-ray diffraction PXRD -and the presence of bonds by means of the fourier transform infrared spectroscopy FT-IR. It was found that the addition of the cellulose filler increased the number of cells in the foams in both cross-sections—parallel and perpendicular to the direction of the foam growth—while reducing the sizes of those cells. Additionally, the foams had closed cell contents of more than 90% and initial thermal conductivity coefficients of 24.8 mW/m∙K. The insulation materials were dimensionally stable, especially at temperatures close to 0 °C, which qualifies them for use as insulation at low temperatures.

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