Aluminum foam is used for applications that requires high level of energy and sound absorption characteristics. UiTM researchers have developed an innovative process to make high strength cellular aluminium foam with help from some salt.
Aluminium foam exhibits unique properties when compared to its dense form, particularly its lightweight characteristics. Generally, the foam can be divided into two categories; closed cell and open cell, both have different characteristics and applications.
The features of the closed cell are, the pores structure is isolated and they are not connected to each other. This type of aluminium foam is suitable for application that requires high level of energy and sound absorption characteristics. It has been used widely in many structural parts, particularly in areas exposed to high damping capacity, for example in the automotive front bumper component.
Meanwhile, the open cell, owing to greater level of connectivity of the pores, the structure has been accepted and used in thermal management applications. One such promising application is as a heat exchanger, particularly as a cooling medium to transfer heat, due to the development of its porous structure, which provides greater surface area, thus, enabling improved heat transfer efficiency. Producing a combined structure of open and closed cell in one volume component appears to be a difficult process due to the different processing techniques involved and their individual limitations.
Therefore, in this study, an innovative processing route for high strength cellular aluminium foam (CAF) by integrating porous and dense structures is presented. The CAF is well known as a light-weight product exhibiting high level of inter-connected porosity which is very useful as a thermal management application, particularly as a heat transfer or cooling medium. However, the level of strength for the CAF is not really promising when it is subjected to high impact; thus, limit its potential application, particularly in the automotive industry.
Subsequently, an alternative route by integrating dense and porous structure has been investigated. The solid aluminium at the centre acts as a pillar providing excellent strength for the surrounding foam structure. The product has demonstrated functionally graded properties which is possible for applications that require both properties of heat transfer and high strength.
The product was fabricated using infiltration of NaCl space holder combined with central solid aluminium foam. It is well known that NaCl has a greater melting point than that of aluminium. Therefore, when aluminium melts, the liquid fills the interstitial spaces between the NaCl grain. Prior to melting, the NaCl is sieved according to the desired porous structure.
The materials (NaCl, central aluminium core and dense Aluminium ingot) are placed in the cylindrical steel mould and heated at temperature range between 670 and 700oC. The NaCl is placed at the bottom mould with aluminium central pillar and bulk Aluminium placed at the top of NaCl so that after the aluminium turns into liquid, it penetrates along the interstitial spaces between NaCl. Upon solidification, the part is removed from the mould and further machining is carried out to remove surface roughness caused by the solidification process. The part is then leached in an ultrasonic water bath in order to remove the NaCl completely.
The final product is the cellular aluminium foam exhibiting excellent interconnected pores structure with dense central pillar. The central solid pillar provides extra strength for the surrounded foam structure. The foams structure produced was examined for its density, porosity and strength by compression test. Thermal conductivity was also carried out to investigate the effect of space holder size and the NaCl fractions on the final properties.
MUHAMMAD HUSSAIN BIN ISMAIL
Faculty of Mechanical Engineering
University Teknologi MARA, Malaysia
University Teknologi MARA
New algorithm for optimized stability of planar-rod objects
11.08.2016 | Institute of Science and Technology Austria
Automated driving: Steering without limits
05.02.2016 | FZI Forschungszentrum Informatik am Karlsruher Institut für Technologie
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences