|
Vol.40, No.8, 910 ~ 915, 2002
|
| Title |
| Research Papers / Materials Processing : A Study on the Mechanical and Sound Absorption Properties of Aluminum Foam |
| 김상열Sang Youl Kim,허보영Bo Young Hur,권철규Chol Kyu Kwon,박수한Soo Han Park,안득규Duck Kyu Ahn |
|
|
|
| Abstract |
| Mechanical properties of metal foams depend on cell type, shape, size, homogeneity, surface area and relative density, and particularly are proportional to its density. Deformation of metal foams includes the plastic deformation and collapse and shows a plateau area followed by yielding point. Metal foams follow the morphological rules that are about cell type, size and homogeneity. Metal foams with homogeneous wall thickness and linear cell boundary show the similar mechanical properties to bulk metal and thickness averaged by diameter affect the mechanical properties more seriously than cell size. In this paper, the effects of holding furnace temperature on macrostructure of Al foams were studied, sound absorption and thermal conductivity tests were carried out and impact test did with different cell size. To avoid the disappearing of bubbles by coalescence or burst, foaming agent(TiH_2) containing gas releasing component was used to fabricate the closed-cell Al foams. Melting was carried out near at 680℃ considering the melting point of recycled Al alloy and gas releasing point of TiH_2. The velocity of decomposition decreased with decrease of the time and temperature. Impact absorption energy of Al foam has 27 ㎏-㎝ at about cell size 2.7 ㎜. The acoustical performance of Al foam is considerably improved: its absorption coefficient shows over NRC 0.7 from 2000 to 4000 ㎐. Thermal conductivity of Al has about 2 W/mk. |
|
|
| Key Words |
| Al foam , Sound absorption , Foaming agent , Viscosity , Closed cell |
|
|
 |
|
