Structure and Deformation of Gradient Metal Foams Produced by Machining

2019 ◽  
Author(s):  
H. Qiao ◽  
T. G. Murthy ◽  
C. Saldana
Keyword(s):  
Aluminum Foam ◽  
Mechanical Performance ◽  
Metal Foams ◽  
Aluminum Foams ◽  
Open Cell ◽  
Computed Tomographic ◽  
Surface Gradient ◽  
Structure Changes

Abstract The effects of surface structure on mechanical performance for open-cell aluminum foam specimens was investigated in the present study. A surface gradient for pore structure and diameter was introduced into open cell aluminum foams by machining-based processing. The structure changes in the strut and pore network were evaluated by computed tomography characterization. The role of structure gradients in affecting mechanical performance was determined using digital volume correlation and in situ compression within the computed tomographic scanner. These preliminary results show that the strength of these materials may be enhanced through surface structural gradients.

Structure and Deformation of Gradient Metal Foams Produced by Machining

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Haipeng Qiao ◽  
Tejas G. Murthy ◽  
Christopher Saldana
Keyword(s):  
Aluminum Foam ◽  
Mechanical Performance ◽  
Metal Foams ◽  
Aluminum Foams ◽  
Open Cell ◽  
Computed Tomographic ◽  
Surface Gradient ◽  
Structure Changes

The effects of surface structure on mechanical performance for open-cell aluminum foam specimens were investigated in the present study. A surface gradient for pore structure and diameter was introduced into open-cell aluminum foams by machining-based processing. The structure changes in the strut and pore network were evaluated by computed tomography characterization. The role of structure gradients in affecting mechanical performance was determined using digital volume correlation and in situ compression within the computed tomographic scanner. These preliminary results show that the strength of these materials may be enhanced through surface structural gradients.

The Effects of Compression and Pore Size Variations on the Liquid Flow Characteristics in Metal Foams

2001 ◽  
Vol 124 (1) ◽  
pp. 263-272 ◽  
Author(s):  
K. Boomsma ◽  
D. Poulikakos
Keyword(s):  
Flow Characteristics ◽  
Maximum Flow ◽  
Metal Foams ◽  
Heat Sinks ◽  
Convection Heat ◽  
Hydraulic Characteristics ◽  
Aluminum Foams ◽  
Transitional Regime ◽  
Open Cell ◽  
Flow Velocities

Open-cell aluminum foams were investigated using water to determine their hydraulic characteristics. Maximum fluid flow velocities achieved were 1.042 m/s. The permeability and form coefficient varied from 2.46×10−10 m2 and 8701 m−1 to 3529×10−10 m2 and 120 m−1, respectively. It was determined that the flowrate range influenced these calculated parameters, especially in the transitional regime where the permeability based Reynolds number varied between unity and 26.5. Beyond the transition regime where ReK≳30, the permeability and form coefficient monotonically approached values which were reported as being calculated at the maximum flow velocities attained. The results obtained in this study are relevant to engineering applications employing metal foams ranging from convection heat sinks to filters and flow straightening devices.

Dynamic Crushing of All-Metallic Corrugated Panels Filled With Close-Celled Aluminum Foams

2015 ◽  
Vol 82 (1) ◽  
Author(s):  
B. Yu ◽  
B. Han ◽  
C. Y. Ni ◽  
Q. C. Zhang ◽  
C. Q. Chen ◽  
...  
Keyword(s):  
Aluminum Foam ◽  
Sandwich Panel ◽  
Dominant Role ◽  
Sandwich Panels ◽  
Rate Sensitivity ◽  
Aluminum Foams ◽  
Foam Filling ◽  
Plastic Hardening ◽  
Insight Into

Under quasi-static uniaxial compression, inserting aluminum foams into the interstices of a metallic sandwich panel with corrugated core increased significantly both its peak crushing strength and energy absorption per unit mass. This beneficial effect diminished however if the foam relative density was relatively low or the compression velocity became sufficiently high. To provide insight into the varying role of aluminum foam filler with increasing compression velocity, the crushing response and collapse modes of all metallic corrugate-cored sandwich panels filled with close-celled aluminum foams were studied using the method of finite elements (FEs). The constraint that sandwich panels with and without foam filling had the same total weight was enforced. The effects of plastic hardening and strain rate sensitivity of the strut material as well as foam/strut interfacial debonding were quantified. Three collapse modes (quasi-static, transition, and shock modes) were identified, corresponding to different ranges of compression velocity. Strengthening due to foam insertion and inertial stabilization both acted to provide support for the struts against buckling. At relatively low compression velocities, the struts were mainly strengthened by the surrounding foam; at high compression velocities, inertia stabilization played a more dominant role than foam filling.

Fatigue of As-Fabricated Open Cell Aluminum Foams

2005 ◽  
Vol 127 (1) ◽  
pp. 40-45 ◽  
Author(s):  
J. Zhou ◽  
Z. Gao ◽  
A. M. Cuitino ◽  
W. O. Soboyejo
Keyword(s):  
Shear Bands ◽  
Digital Camera ◽  
Image Correlation ◽  
Ex Situ ◽  
Aluminum Foams ◽  
Open Cell ◽  
Strain Jump ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

This paper presents the results of the combined experimental investigation and digital image correlation (DIC) analysis of the fatigue failure of open cell aluminum foams. Compression–compression cyclic loads were applied to foam specimens under the as-fabricated condition. Following characterization of the S-N curve behavior, the macroscale deformation of the tested foam under fatigue was recorded using an in-situ digital camera. The deformation sequence was then analyzed using DIC technique. It was found that foams failed with an abrupt strain jump when shear bands were formed, and serious deformation up to more than 30% was developed in the center of the shear band. The ex-situ scanning electron microscopy analysis indicated that the abrupt strain jump was due to the microscale damage accumulation in struts where surface cracks were formed and propagated.

Application of Superplastic Flow to Manufacturing of Microcellular Aluminum Foams

2005 ◽  
Vol 475-479 ◽  
pp. 3021-3024 ◽  
Author(s):  
Shinya Kamimura ◽  
Koichi Kitazono ◽  
Eiichi Sato ◽  
Kazuhiko Kuribayashi
Keyword(s):  
Thermal Conductivity ◽  
Cell Shape ◽  
Aluminum Foam ◽  
Oblate Spheroid ◽  
Metal Foams ◽  
Aluminum Foams ◽  
Roll Bonding ◽  
Heat Insulator ◽  
5083 Aluminum Alloy ◽  
Superplastic Condition

A new application of superplasticity was proposed in the manufacturing process of metal foams. Preform sheets were manufactured using superplastic 5083 aluminum alloy sheets through accumulative roll-bonding (ARB) process. Microcellular aluminum foam plates with 50% porosity were produced through solid-state foaming under the superplastic condition. The cell shape was oblate spheroid, which is effective to reduce the thermal conductivity. The present aluminum foam plates have a potential as an excellent heat insulator.

Preliminary NVH Characterization of Metal Foam-Polymer Interpenetrating Phase Composites

2009 ◽  
Author(s):  
Satish Sharma ◽  
Nassif E. Rayess ◽  
Nihad Dukhan
Keyword(s):  
Mathematical Model ◽  
Thermal Stability ◽  
Hybrid Material ◽  
Aluminum Foam ◽  
Metal Foam ◽  
Dynamic Properties ◽  
Metal Foams ◽  
Thermoplastic Polymer ◽  
Open Cell

The damping and basic dynamic properties of a novel type of multifunctional hybrid material known as Metal Foam-Polymer Composite are investigated. This material is obtained by injection molding a thermoplastic polymer through an open cell Aluminum Foam, in essence creating two contiguous morphologies; an Aluminum Foam interconnected “skeleton” with the open pores filled with a similarly interconnected polymer substructure. This coexistence of both materials allows each to contribute its salient properties (e.g. the plastics contributing surface toughness and the metal foams contributing thermal stability). Basic damping testing results are presented for various Aluminum Foam porosities and pore sizes as well as for three types of polymers. A basic mathematical model of the damping is also presented. The integrity of the interface between the Aluminum Foam and the Polymer is discussed in terms of its effect on the overall material damping.

Effect of Precursor Design on Preparing Open-Cell Aluminum Foam Fabricated by Space-Holder Method

2021 ◽  
Vol 1035 ◽  
pp. 169-174
Author(s):  
Tan Wan ◽  
Yuan Liu ◽  
Fa Ting Xu ◽  
Xiang Ding
Keyword(s):  
Aluminum Foam ◽  
Functional Performance ◽  
Cell Structure ◽  
Flow Characteristics ◽  
Aluminum Foams ◽  
Open Cell ◽  
Lower Porosity ◽  
Negative Effect ◽  
Spherical Cells ◽  
Good Flow

Open-cell aluminum foams with spherical cells have great potential application due to their reliable structural and functional performance. However, a problem of poor cell connectivity always arises during fabrication. Three precursor designs were explored to optimize the cell structure. The results showed that the lack of the treatment of the space holders caused poor cell connectivity and a lower porosity, which could be resolved by introducing alcohol as a binder or hot-pressing space holders in precursor designs. Nevertheless, a poor fluid of the granules in the former had a negative effect on porosity improvement, whereas the latter created a precursor with strong bonding between the granules with good flow characteristics and led to a significant improvement in cell connectivity and porosity. This work could provide an approach to designing precursor structures in order to tailor the structure of the final open-cell aluminum foam.

Preparation of High Performance Aluminum Foam Using Carbon Fibers as Stabilizing Additive

2011 ◽  
Vol 308-310 ◽  
pp. 53-57
Author(s):  
Zhuo Kun Cao ◽  
Huan Liu ◽  
Jin Jing Du ◽  
Guang Chun Yao
Keyword(s):  
Mechanical Property ◽  
Carbon Fibers ◽  
High Performance ◽  
Aluminum Foam ◽  
Mechanical Performance ◽  
Metallic Foams ◽  
Aluminum Foams ◽  
Foam Structure ◽  
Stable Foam ◽  
Fiber Fraction

Carbon fibers are used as novel stabilizing additives for aluminum foams production at the aim of manufacturing metallic foams of high mechanical performance. The effect of carbon fiber fraction on the foam structure and mechanical property is studied in the present paper. Results shows that the change in foam structure can be slowed down by increasing fiber fraction, which would led to more stable foam. The yield strength of aluminum foams increase with fiber fraction, but the foams are also getting brittle. High performance aluminum foams can also prepared by using aluminum alloy as start material, and the resulting foams show much higher compressive strength than that of commercial aluminum foams.

A Theoretical and Experimental Study on the Dynamic Constitutive Model of Aluminum Foams

2010 ◽  
Vol 638-642 ◽  
pp. 1878-1883
Author(s):  
Ji Lin Yu ◽  
Er Heng Wang ◽  
Liu Wei Guo
Keyword(s):  
Experimental Study ◽  
Material Parameter ◽  
Aluminum Foam ◽  
Extended Model ◽  
Strain Rates ◽  
Compression Tests ◽  
Dynamic Tests ◽  
Aluminum Foams ◽  
Open Cell ◽  
Dynamic Experiments

The phenomenological constitutive framework for compressible elasto-plastic solids presented by Chen and Lu [1] is extended to the dynamic cases by assuming that the material parameter curves in the stress potential depend also on the strain rate. To check the applicability of the extended model, three types of dynamic experiments, i.e., uniaxial compression, lateral-constrained compression and side-constrained compression tests, are conducted for an open-cell aluminum foam at different strain rates. The first two types of dynamic tests are used as characteristic tests to determine the material parameter curves at different strain rates which are then used to construct the stress potential function in the model. The results show that the stress-strain curves under side-constrained compression predicted by the model are in agreement with those obtained experimentally.

In‐situ and ex‐situ micro mechanical testing of open‐cell metal foams

PAMM ◽  
2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Anne Jung ◽  
Jutta Luksch ◽  
Thomas Bleistein ◽  
Jerome Adrien ◽  
Eric Maire
Keyword(s):  
Mechanical Testing ◽  
Metal Foams ◽  
Ex Situ ◽  
Open Cell
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