Metal Hollow Sphere Structures
Typical Properties
Structure
Acoustical Properties
Influence of Sphere Diameter on Sound Sound Absorption of optimized Steel
Structure (Example: Car Exhaust System)
Absorption Rate (Examples, Compared to
Mineral Fibre)
Cell size 0.5  10 mm
Shell thickness 20  1000 µm 100
Porosity 80  96 % 80
Density 0.3  1.5 g/cm3 60
Microporosity
40
(shells) 0  10 %
20
0
200 400 600 800 1000 1200 1400 1600
Frequency (Hz)
Mechanical Properties Thermal Properties
Specific Energy Absorption of Compression Strength of Example: Thermal Conductivity of Mo
Steel Structures (Examples) Steel Structures (Example) Hollow Sphere Structure
20
Helium 1 bar
Helium 1 bar
Helium 1 bar
0,42 g/cmł
2.0
2.0
2.0
0.41 g/cmł
N2 1 bar
N2 1 bar
N2 1 bar
0.45 g/cmł
15
0.44 g/cmł
0.46 g/cmł
1.5
1.5
1.5
alloyed steel (Fe-P 0.6%)
10
1.0
1.0
1.0
Measurementsin N2
Measurementsin N2
5
0.5
0.5
0.5
unalloyed steel
l Mo= 140 W/mK
l = 140 W/mK
l = 140 W/mK
Mo
Mo
0
0.0
0.0
0.0
0 20 40 60 80
0 200 400 600 800 1000 1200
0 200 400 600 800 1000 1200
0 200 400 600 800 1000 1200
Compression (%)
Temperature [°C]
Temperature [°C]
Temperature [°C]
Absorption Rat e (% )
Compression Strength (MPa)
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