My recent research title is "Production and Characterization of Metallic Foams", particularly Aluminum (Al) Foams. There are various production methods and I am using "Powder Metallurgy Route". Although foaming takes place at temperatures higher than melting point of Al (between 700-850 °C) and material is mostly in liquid form, because starting materials are powders this name is often used. Method is patented by Fraunhofer Research Institute, Germany and products are already commercialized (e.g. Alulight).
The purpose of my study is to understand and analyze the stabilizing and improved foaming effects of oxide and carbide ceramics on aluminum foams which makes them in fact metal-matrix composite (MMC) foams.
First stage in foam production is selection of powders. Matrix material is Al powder. I am using air atomized powders of Al supplied from Gürel Makina A.Ş, Gebze, a domestic manufacturer of metal powders and PM products. Foaming is achieved by addition of a "blowing agent", a powder which releases "gas" at elevated temperatures. Entrapped gas in Al matrix initiates expansion. Titanium hydride (TiH2) which starts decomposition at approximately 400 °C is believed to be the most appropriate material for this purpose. It is important to know that maximum gas release of the blowing agent must be close to melting temperatures of the surrounding matrix for good foaming. Unfortunately this material cannot be found in domestic market and is imported. I must also note that this is the most expensive raw material. However, only 0.6-1 wt% of this material is enough for foam production in this method unlike other methods like foaming of melts which requires 6-10 wt%. Finally by 5-20 wt% of ceramic particle addition we are ready for the next step, preparation of the mixture.
At this stage PM method has some advantages. Most important one is the ease of mixing ceramic powders with metal powders at any size and amount. This is much more difficult when working with Al melts. You can also add other powders like Si, Mg and Cu which will give you Al alloy like precursors.
Having the mixture in hand, next step is compaction. Target here is to have a "dense" matrix, very close to theoretical density of matrix material (for Al it is approximately 2700 kg/m3). This can be done with some of the well known PM techniques, cold compaction and hot forming, or hot compaction. Achievable density by cold forming is usually not enough for foaming. A subsequent "hot" process is necessary.
Now it is time for the "soothing crème" of this study, foaming. Precursor is placed in a preheated furnace (700-850 °C) and all I have to do is sit back on a lab stool and watch. Unfortunately this lasts for only 3 to 10 minutes. Then still expanding foam is taken out from the furnace for cooling.
Density of foamed products can change from 25-30% to 45-50% of matrix material which is mostly below the density of water. Yes, Al foams can float on water.
If you are interested in Al foams, or generally in metallic foams I recommend you to visit metalfoam.net a portal like site which provides information about current research, companies in this field and recent literature. Site is organized by Prof. Jonh Banhart who is a pioneer in this area.
Date of Birth
April 20, 1976
Place of Birth
Istanbul - Turkey
Excellent command in both written and spoken English, Beginner level in German
PhD Student in Mechanical Engineering Department, Boğaziçi University, Istanbul - Turkey
1999 - 2002
MS in Mechanical Engineering, Boğaziçi University, Istanbul - Turkey
1993 - 1998
BS in Mechanical Engineering, İstanbul Technical University, Istanbul - Turkey
Research Assistant, Mechanical Engineering Department Boğaziçi University, Istanbul - Turkey
Summer Training Production Department (Gear units) A. Friedr. Flender AG., Bocholt, Germany
Packages Matlab, ANSYS, AutoCAD, ABAQUS
Languages Visual Basic
Software MS Office Applications
BUMED (Boğaziçi University Alumni)
ASME (The American Society of Mechanical Engineers, member since 1999)
Current Job Description/Responsibilities
Materials Science laboratory in B.U.
Manufacturing Techniques laboratory in B.U.
Evaluating laboratory reports and projects of ME 212 Materials Science and ME 318 Manufacturing Techniques Class in B.U.
Organizing and helping M.Sc. Students Experimental Studies in B.U. Materials Laboratory Facility.