Investigation of microstructural and mechanical properties of cell walls of closed-cell aluminium alloy foams

2016 ◽  
Vol 666 ◽  
pp. 245-256 ◽  
Author(s):  
M.A. Islam ◽  
M.A. Kader ◽  
P.J. Hazell ◽  
A.D. Brown ◽  
M. Saadatfar ◽  
...  
Author(s):  
D. Puspitasari ◽  
T.L. Ginta ◽  
P. Puspitasari ◽  
M. Mustapha

Purpose: The purpose of this study was to investigate the influence of three thermal processing parameter called stress relieving on mechanical properties of the aluminium alloy foam. Design/methodology/approach: The samples were undergone by stress relieving method using vacuum furnace. Hardness measurement was carried out using microhardness Vickers at 150 mN load and 15 s loading time. Compressive strength, plateau stress and energy absorption were calculated using a universal testing machine. Findings: It was found that the highest value of hardness of 192.78 Hv was obtained when the stress relieving process is set with the following parameters: heating (500°C); holding time (120 min) and stabilization temperature (450°C). Since higher heating temperature and longer holding time produce sample with larger grain size and has an adverse effect on the hardness value It was revealed that the mechanical properties of aluminium alloy foam were enhanced when the heating temperature was decreased, holding temperature was diminished and the stabilization temperature was increased. Overall, the presented results showed that the thermal processing parameters such as heating temperature, holding time and stabilization temperature have a significant influence on improving the mechanical properties of aluminium alloy foam. Research limitations/implications: The properties of closed-cell aluminium alloy foam are highly sensitive and depend on the post heat treatment process. The processing parameters should be controlled in order to manipulate the properties of closed-cell aluminium alloy foam. Originality/value: To investigate the influences of these processing parameters on the physical and mechanical properties of the closed-cell aluminium alloy foam.


2010 ◽  
Vol 5 (2) ◽  
pp. 55-63
Author(s):  
G. Raghu Babu ◽  
◽  
K.G.K. Murti ◽  
G. Ranga Janardhana ◽  
◽  
...  

Author(s):  
Mathew Alphonse ◽  
V.K. Bupesh Raja ◽  
M.S. Vivek ◽  
N.V. Sai Deepak Raj ◽  
M. Satya Sai Darshan ◽  
...  

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 968
Author(s):  
Dong Xing ◽  
Xinzhou Wang ◽  
Siqun Wang

In this paper, Berkovich depth-sensing indentation has been used to study the effects of the temperature-dependent quasi-static mechanical properties and creep deformation of heat-treated wood at temperatures from 20 °C to 180 °C. The characteristics of the load–depth curve, creep strain rate, creep compliance, and creep stress exponent of heat-treated wood are evaluated. The results showed that high temperature heat treatment improved the hardness of wood cell walls and reduced the creep rate of wood cell walls. This is mainly due to the improvement of the crystallinity of the cellulose, and the recondensation and crosslinking reaction of the lignocellulose structure. The Burgers model is well fitted to study the creep behavior of heat-treated wood cell walls under different temperatures.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 249
Author(s):  
Przemysław Rumianek ◽  
Tomasz Dobosz ◽  
Radosław Nowak ◽  
Piotr Dziewit ◽  
Andrzej Aromiński

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.


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