Investigation of producibility of aluminium based metallic foam by mechanical alloying method

The aim of this study is to search the production parameters of metallic foam that has homogeneous porous structure. 0,8-1-1,2% TiH2 powder as a foamer and 0,6% Mg were added into the matrix material of pure aluminium and AlSi7 powder in the production of Metal Matrix Composite (MMC) metallic powder. 2%, 4%, 8% ratios of SiC and Al2O3 powders were used as a reinforcement element. Powders were pre-mixed in three dimensional turbola instrument by 30 minutes and then mixed in Szegvari type Mechanical Alloying (MA) Mill with 350 rev/min milling speed by 15, 30, 60, 120 minutes. Steel balls wtih a diameter of 10mm were used and 1/10 value is selected as a powder/ball ratio during the mechanical alloying procass. Powders were pressed in a die of 30mm. diameter under 450Mpa pressure. Pressed powders were extruded after pre-heating process at 550ºC for 2 hours. Later, they became as plate of 5mm thickness after pre-heating process at 500ºC by 30 minutes and foaming process was applied at 690ºC and 710ºC. Experimental studies showen that increasing MA times have increased the densities and disorders were observed in porous structures of powder materials. As the quantity of TiH2 is increased in the structure, the density of powder material is decreased and porosities are dispersed more homogeneously in the structure.Key Words : Powder Metallurgy, Metallic Foam, Metal Matrix Composite, Mechanical AlloyingPages: